Here I will be laying out the main ideas of some of history’s most important philosophers. These will be extremely brief, simplified explanations of some of the big ideas for each of these philosophers. This should not be construed as a replacement or substitute for a deeper reading on these philosophers.

Preface

As I said, these summaries will be very brief. Entire books could (and have been) written by, and about, each and every one of these philosophers and their various ideas. There have been numerous ways of interpreting, and refuting, practically every word I’ll be writing here. As such, it’s important to keep in mind that what will be written here is not the definitive or settled consensus, though I have tried to stay within the sort of “orthodox” interpretation on all these things. The point of this post is to be a resource for (A) seeing the historical development of thought and (B) getting a general sense of what each of these thinkers was about.

In the name of brevity, there will be minimal biographical information provided for each of these philosophers, aside from the best known dates of birth and death. Even though historical context is important, this is meant to be a quick overview of main concepts.

Most of what will be here is western philosophy, which is European, American, and some Middle Eastern. I am likely not qualified to speak on much eastern philosophy (assuming I’m even qualified to speak on western philosophy), so entries on East Asian, South Asian, and African philosophy will be minimal, covering only a few of the most towering figures in those areas.

Also note that this will be a progressive entry, where I will update and add to it over time, so what you see is likely not the final form, and there will likely be empty entries (names without any information for them). Feel free to leave comments asking for clarifications or with suggestions for further additions. Without further ado, lets get into it.

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Ancient to Medieval Philosophy

The ancients (mostly Greek) and the medieval scholastics (mostly European and Arabic) can perhaps be broadly thought of as the pre-scientific philosophers. Their concerns (speaking very generally) tended to be more metaphysical and their approach tended to be deferential to their predecessors. Notable exceptions were people like Socrates, Plato, and Aristotle in the west and Lao Tzu, Siddhartha Gautama, and Confucius in the east (hence why they are such towering figures). The pre-Socratics were original thinkers as well, but they suffer from having so little known about them (much of it coming from sources like Aristotle, who was looking to refute them).

Pre-Socratics

Orpheus (said to have lived several generations before Homer): a Thracian bard, legendary musician and prophet in ancient Greek religion. He was also a renowned poet and, according to the legend, travelled with Jason and the Argonauts in search of the Golden Fleece, and even descended into the Underworld of Hades to recover his lost wife Eurydice. Many Greeks believed Orpheus to be a real person, but others (like Aristotle) believed he was just a legend.

1. Orphism: religious beliefs and practices originating in the ancient Greek and Hellenistic world, associated with literature ascribed to the mythical poet Orpheus, who descended into the Greek underworld and returned. Orphics revered Dionysus (who once descended into the Underworld and returned) and Persephone (who annually descended into the Underworld for a season and then returned). Orphism has been described as a reform of the earlier Dionysian religion, involving a re-interpretation or re-reading of the myth of Dionysus and a re-ordering of Hesiod‘s Theogony, based in part on pre-Socratic philosophy.

Homer (8th or 9th century): legendary author to whom the authorship of the Iliad and the Odyssey (the two epic poems that are the foundational works of ancient Greek literature) is attributed. He is regarded as one of the greatest and most influential authors of all time.

Hesiod (8th or 9th century): generally regarded by Western authors as ‘the first written poet in the Western tradition to regard himself as an individual persona with an active role to play in his subject.’ Ancient authors credited Hesiod and Homer with establishing Greek religious customs. Modern scholars refer to him as a major source on Greek mythology, farming techniques, early economic thought, Archaic Greek astronomy, cosmology, and ancient time-keeping.

Thales of Miletus (624 B.C.E. – 548 B.C.E.): Water.

1. “That from which is everything that exists and from which it first becomes and into which it is rendered at last, its substance remaining under it, but transforming in qualities, that they say is the element and principle of things that are. …For it is necessary that there be some nature (φύσις), either one or more than one, from which become the other things of the object being saved… Thales the founder of this type of philosophy says that it is water.” -Aristotle speaking on Thales
2. Thales’ Theorem states that if A, B, and C are distinct points on a circle where the line AC is a diameter, then the angle ∠ABC is a right angle.

Anaximander of Miletus (610 B.C.E. – 546 B.C.E.): Apeiron.

1. Claimed that nature is ruled by laws, just like human societies, and anything that disturbs the balance of nature does not last long.
2. Anaximander explains how the four elements of ancient physics (air, earth, water and fire) are formed, and how Earth and terrestrial beings are formed through their interactions. Unlike other Pre-Socratics, he never defines this principle precisely, and it has generally been understood (e.g., by Aristotle and by Saint Augustine) as a sort of primal chaos. According to him, the Universe originates in the separation of opposites in the primordial matter Apeiron (“that which is limitless”). It embraces the opposites of hot and cold, wet and dry, and directs the movement of things; an entire host of shapes and differences then grow that are found in “all the worlds” (for he believed there were many).

Anaximenes of Miletus (586 B.C.E. – 526 B.C.E.): Ancient Greek, Ionian Pre-Socratic philosopher from Miletus in Asia Minor, active in the latter half of the 6th century BC. The details of his life are obscure because none of his work has been preserved. Air as the arche, with more condensed air made for colder, denser objects and more rarefied air made for hotter, lighter objects.

Xenophanes of Colophon (570 B.C.E. – 475 B.C.E.): Greek philosopher, theologian, poet, and critic of Homer from Ionia who traveled throughout the Greek-speaking world in early Classical Antiquity. As a poet, Xenophanes was known for his critical style, writing poems that are considered among the first satires.

1. Water and Earth: Xenophanes concluded from his examination of fossils of sea creatures that were found above land that water once must have covered all of the Earth’s surface. He used this evidence to conclude that the cosmic principle of the universe was a tide flowing in and out between wet and dry, or earth (γῆ) and water (ὕδωρ). These two extreme states would alternate between one another, and with the alternation human life would become extinct, then regenerate (or vice versa depending on the dominant form).
2. Reincarnation: These two extreme states (wet and dry) would alternate between one another, and with the alternation human life would become extinct, then regenerate (or vice versa depending on the dominant form).

Pythagoras of Samos (570 B.C.E. – 495 B.C.E.): Ionian Greek philosopher and the eponymous founder of Pythagoreanism. His political and religious teachings were well known in Magna Graecia and influenced the philosophies of Plato, Aristotle, and, through them, the West in general. Namesake of the Pythagorean Theorem.

Lao Tzu (ca. 571 B.C.E.): alternatively Laozi or Lao-Tze. Author of the Tao Te Ching and founder of Taoism (Daoism). The existence of Laozi is somewhat mythical, with much of Taoism actually coming from a later philosopher Zhuangzi (aka Zhuang Zhou) who lived between 369 B.C.E. and 286 B.C.E. As with much of eastern philosophy, I am quite unqualified to speak on it, so I am going to leave some links that do a better job of explaining it than I could (text is all copied and pasted from the linked article).

1. Laozi: “The name “Laozi” is best taken to mean “Old (lao) Master (zi),” and Laozi the ancient philosopher is said to have written a short book, which has come to be called simply the Laozi, after its putative author, a common practice in early China.”
2. Daoism: “Daoism is an umbrella that covers a range of similarly motivated doctrines. The term “Daoism” is also associated with assorted naturalistic or mystical religions.”
3. Religious Daoism: “Even if the term “religious Daoism” is accepted, it is not clear which entity it should define, and different scholars might explain its meaning in different ways. Should “religion” include all of Daoism except for its “philosophy”? This would probably exclude the views of the Daode jing (Book of the Way and Its Virtue; §1.1 below), which Daoists have seen as an integral part—in fact, as the source—of their tradition. Omitting these views would be something like writing a survey of Christianity that intentionally neglects to consider the thought and works of the theologians. Should “religion” only include communal ritual with the related pantheons of gods, on the one hand, and the priestly and monastic institutions, on the other? If so, an article on “religious Daoism” would exclude meditation, alchemy, and other individual practices that Daoists—including those who did not practice them—have seen as major components of their tradition.”
4. Neo-Daoism: “The term “Neo-Daoism” (or “Neo-Taoism”) seeks to capture the focal development in early medieval Chinese philosophy, roughly from the third to the sixth century C.E. Chinese sources generally identify this development as Xuanxue, or “Learning (xue) in the Profound (xuan).””
5. Metaphysics in Chinese Philosophy: “[W]hile European metaphysics has tended to center on problems of reconciliation (how ontologically distinct things can interact), Chinese metaphysics has been more concerned with problems of distinction. The most central problems are around the status of individualized things, the relationship between the patterns of nature and specifically human values, and how to understand the ultimate ground of the world in a way that avoids either reification or nihilism. These become problems precisely because of the underlying assumptions of holism and change.”

The following videos are a great introduction to Daoism:

Siddhartha Gautama (ca. 563 B.C.E. – ca 483 B.C.E.): an ascetic and a religious teacher of South Asia who lived in the latter half of the first millennium BCE. He is the founder of Buddhism and revered by Buddhists as an enlightened being whose teachings sought a path to freedom from ignorance, craving, rebirth and suffering. Probably the broadest teachings common to Buddhism are the Four Noble Truths and the Noble Eight-Fold Path, which I will explicate below:

1. Four Noble Truths (source): this is all just copy-pasted from the Wikipedia article
   1. dukkha (suffering, incapable of satisfying, painful) is an innate characteristic of existence in the realm of samsara;
   2. samudaya (origin, arising, combination; ’cause’): together with dukkha arises taṇhā (“craving, desire or attachment, lit. “thirst”);
   3. nirodha (cessation, ending, confinement): dukkha can be ended or contained by the renouncement or letting go of this taṇhā; the confinement of tanha releases the excessive bind of dukkha;
   4. magga (path, Noble Eightfold Path) is the path leading to the confinement of tanha and dukkha
2. The Noble Eight-Fold Path (source): this is all just copy-pasted from the Wikipedia article
   1. Right Resolve or Intention: the giving up of home and adopting the life of a religious mendicant in order to follow the path; this concept aims at peaceful renunciation, into an environment of non-sensuality, non-ill-will (to loving kindness), away from cruelty (to compassion). Such an environment aids contemplation of impermanence, suffering, and non-Self.
   2. Right Speech: no lying, no rude speech, no telling one person what another says about him to cause discord or harm their relationship.
   3. Right Conduct or Action: no killing or injuring, no taking what is not given, no sexual misconduct, no material desires.
   4. Right Livelihood: no trading in weapons, living beings, meat, liquor, and poisons.
   5. Right Effort: preventing the arising of unwholesome states, and generating wholesome states, the bojjhagā (Seven Factors of Awakening). This includes indriya-samvara, “guarding the sense-doors”, restraint of the sense faculties.
   6. Right Mindfulness (sati; Satipatthana; Sampajañña): “retention”, being mindful of the dhammas (“teachings”, “elements”) that are beneficial to the Buddhist path. In the vipassana movement, sati is interpreted as “bare attention”: never be absent minded, being conscious of what one is doing; this encourages the awareness of the impermanence of body, feeling and mind, as well as to experience the five aggregates (skandhas), the five hindrances, the four True Realities and seven factors of awakening.
   7. Right samadhi (passaddhi; ekaggata; sampasadana): practicing four stages of dhyāna (“meditation”), which includes samadhi proper in the second stage, and reinforces the development of the bojjhagā, culminating into upekkha (equanimity) and mindfulness. In the Theravada tradition and the vipassana movement, this is interpreted as ekaggata, concentration or one-pointedness of the mind, and supplemented with vipassana meditation, which aims at insight.
   8. Right View: our actions have consequences, death is not the end, and our actions and beliefs have consequences after death. The Buddha followed and taught a successful path out of this world and the other world (heaven and underworld/hell). Later on, right view came to explicitly include karma and rebirth, and the importance of the Four Noble Truths, when “insight” became central to Buddhist soteriology.

I am quite unqualified to speak on Buddhism with any authority. I will link to some great articles on Buddhism and offer some videos.

1. The Buddha: “teachings, preserved in texts known as the Nikāyas or Āgamas, concern the quest for liberation from suffering. While the ultimate aim of the Buddha’s teachings is thus to help individuals attain the good life, his analysis of the source of suffering centrally involves claims concerning the nature of persons, as well as how we acquire knowledge about the world and our place in it. These teachings formed the basis of a philosophical tradition that developed and defended a variety of sophisticated theories in metaphysics and epistemology.”
2. Mind in Indian Buddhism:
3. Ethics in Indian and Tibetan Buddhism
4. Nāgārjuna (ca 150–250 CE): “the most important Buddhist philosopher after the historical Buddha himself and one of the most original and influential thinkers in the history of Indian philosophy. His philosophy of the “middle way” (madhyamaka) based around the central notion of “emptiness” (śūnyatā) influenced the Indian philosophical debate for a thousand years after his death”
5. Abhidharma: ” [the method of] Abhidharma is to be contrasted with Sūtrānta, the system of the Buddha’s discourses (Skt., sūtras, Pali, suttas). Unlike the earlier Buddhist discourses that are colloquial in nature, the Abhidharma method presents the Buddha’s teachings in technical terms that are carefully defined to ensure analytical exactitude. In content, Abhidharma is distinctive in its efforts to provide the theoretical counterpart to the Buddhist practice of meditation and, more broadly, a systematic account of sentient experience.”
6. Japanese Zen Buddhism: “aims at the perfection of personhood. To this end, sitting meditation called “za-zen” is employed as a foundational method of prāxis across the different schools of this Buddha-Way—which is not an ideology, but a way of living. Through za-zen the Zen practitioner attempts to embody non-discriminatory wisdom vis-à-vis the meditational experience known as “satori” (enlightenment). A process of discovering wisdom culminates, among other things, in the experiential apprehension of the equality of all thing-events.”

I could never do a better job of explaining Buddhism than the following videos:

Confucius (September 28, 551 B.C.E. – April 11, 479 B.C.E.): real name Kǒng Fūzǐ. Confucius was a Chinese philosopher and politician of the Spring and Autumn period who is traditionally considered the paragon of Chinese sages. Confucius’s teachings and philosophy underpin East Asian culture and society, remaining influential across China and East Asia to this day.

1. Analects (from Wikipedia): It is believed to have been written during the Warring States period (475–221 BC), and it achieved its final form during the mid-Han dynasty (206 BC–220 AD). By the early Han dynasty the Analects was considered merely a “commentary” on the Five Classics, but the status of the Analects grew to be one of the central texts of Confucianism by the end of that dynasty. The Five Classics are the following:
   1. I Ching or Classic of Change or Book of Changes.
   2. Classic of Poetry or Book of Songs is the earliest anthology of Chinese poems and songs.
   3. Book of Documents or Book of History Compilation of speeches of major figures and records of events in ancient times embodies the political vision and addresses the kingly way in terms of the ethical foundation for humane government.
   4. Book of Rites describes the social forms, administration, and ceremonial rites of the Zhou Dynasty.
   5. Spring and Autumn Annals chronicles the period to which it gives its name, Spring and Autumn period (771–476 BCE) and these events emphasise the significance of collective memory for communal self-identification, for reanimating the old is the best way to attain the new.

Again, I defer to the following videos (made by the same person as the ones above on Buddha).

Sun Tzu (544 B.C.E. – 496 B.C.E.): Chinese military general, strategist, philosopher, and writer who lived during the Eastern Zhou period. Sun Tzu is traditionally credited as the author of The Art of War, an influential work of military strategy that has affected both Western and East Asian philosophy and military thinking.

Heraclitus of Ephesus (535 B.C.E. – 475 B.C.E.): Fire.

1. Everything changes: “Everything changes and nothing remains still … and … you cannot step twice into the same stream.”
2. If objects are new from moment to moment so that one can never touch the same object twice, then each object must dissolve and be generated continually momentarily and an object is a harmony between a building up and a tearing down. Heraclitus calls the oppositional processes ἔρις (eris), “strife”, and hypothesizes that the apparently stable state, δίκη (dikê), or “justice”, is a harmony of strife.

Parmenides of Elea (Born c. 515 B.C.E.): The Parmenidean One.

1. The every-day perception of reality of the physical world is mistaken, and that the reality of the world is ‘One Being’ – an unchanging, ungenerated, indestructible whole.
2. He argued that movement was impossible because it requires moving into “the void”, and Parmenides identified “the void” with nothing, and therefore (by definition) it does not exist.

Anaxagoras (510 B.C.E. – 428 B.C.E.): Disagreed with Parmenides.

1. Described the world as a mixture of primary imperishable ingredients, where material variation was never caused by an absolute presence of a particular ingredient, but rather by its relative preponderance over the other ingredients; in his words, “each one is… most manifestly those things of which there are the most in it”.
2. He introduced the concept of Nous (Cosmic Mind) as an ordering force, which moved and separated out the original mixture, which was homogeneous, or nearly so.

Empedocles of Acagras (494 B.C.E. – 434 B.C.E.): Fire, Air, Water, Earth.

1. The four elements are eternal and unchanging, but are brought together and separated by Love and Strife. As the best and original state, there was a time when the pure elements and the two powers co-existed in a condition of rest and inertness in the form of a sphere. The elements existed together in their purity, without mixture and separation, and the uniting power of Love predominated in the sphere: the separating power of Strife guarded the extreme edges of the sphere. Since that time, strife gained more sway and the bond which kept the pure elementary substances together in the sphere was dissolved.
2. He was a firm believer in Orphic mysteries, as well as a scientific thinker and a precursor of physics.
   • Like Pythagoras, Empedocles believed in the transmigration of the soul, that souls can be reincarnated between humans, animals and even plants.

Leucippus (5^th Century B.C.E.): Atomist – pre-Socratic Greek philosopher who has been credited as the first philosopher to develop a theory of atomism. Leucippus’ reputation, even in antiquity, was obscured by the reputation of his much more famous pupil, Democritus, who is also credited with the first development of atomic theory.

Democritus (460 B.C.E. – 370 B.C.E.): Atomist – Ancient Greek pre-Socratic philosopher from Abdera, primarily remembered today for his formulation of an atomic theory of the universe. None of his work has survived.

Protagoras of Abdera (490 B.C.E. – 420 B.C.E.): pre-Socratic Greek philosopher and rhetorical theorist. He is numbered as one of the sophists by Plato. In his dialogue Protagoras, Plato credits him with inventing the role of the professional sophist.

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The Big Three

Socrates (470 B.C.E. – 399 B.C.E.):

1. Socrates does not have a lot of philsophy of his own that has been passed down to posterity since he never wrote anything himself. All we know about him comes from second hand accounts. That being said, probably the main thing attributed to him is the so-called Socratic method, which is interrogating a person’s presuppositions with questions that expose where a person’s beliefs are contradictory. This is often thought to be a precursor of Hegelian/Marxian dialectical logic.

Plato (428 B.C.E. – 348 B.C.E.):

1. Platonic Forms or Ideas are one of Plato’s largest contributions to philosophy. This is the notion that all the physical objects that we come in contact with are deviations from a perfect version of themselves. There is a realm of Forms, for instance, where there is the perfect Tree, and all the trees that you ever come in contact with are imperfect approximations of this. This is true as well of more abstract things, such as perfect Justice and perfect Love.
2. Because we are exposed to imperfect versions of things like Justice and Love, it takes the great mind of a philosopher to glimpse the perfect Forms of these things. This is where the famous allegory of the cave comes in. Plato asks us to consider people chained in a cave, only able to see shadows cast on the wall in front of them. All they have ever known are the shadows, and so this is their whole world. Then one of these people becomes freed and walks out of the cave to see the real world for the first time. If that person were to go back down and tell his fellows about the world above, they would likely think the escapee mad, yet the escapee is someone who knows more truth than them. Someone who has glimpsed the perfect Forms is like the person who has left the cave – a philosopher.
3. It’s from this that Plato’s Republic is based, where we have philosopher kings at the top, since they have glimpsed the Forms and therefore have much greater knowledge than everyone else. Plato splits his ideal Republic into a hierarchy of three strata:
   1. Philosopher Kings or Guardians: wise rulers who live communally
   2. Auxiliaries: soldiers and police
   3. Craftsman: the bulk of the population who carry out all the labor jobs
4. This Republic is a type of aristocracy, which Plato thought the best form of government. The other ones he thought, in descending order of desirability, are the levels that each such government will degenerate into over time; it is the wise philosopher kings of an aristocracy that must prevent this. The following are the other types:
   1. Timocracy: essentially a government where the Auxiliaries have taken over. Plato thought that Sparta, with its warrior rulers, was a Timocracy. This is more favorable than Oligarchy because the soldiers are at least high-minded and honorable people.
   2. Oligarchy: rule by a small number of rich and influential people. This is better than democracy, Plato thinks, because at least such people would be more enlightened than the masses.
   3. Democracy: rule by the masses.
   4. Tyranny: when the most vicious and ruthless people among the masses take power and rule by terror and violence.

Aristotle (384 B.C.E. – 322 B.C.E.): Aristotle is probably the most important philosopher in western philosophy. His shadow still hangs over just about everything in western philosophy, whether someone is using his ideas or attempting to refute or subvert them. It would not even be that much of an exaggeration to argue that until perhaps the 1800’s that all of philosophy was just extensions, footnotes, and commentaries on Aristotle.

1. Categories: the ten ways that Aristotle said are the ways in which something can be described. The first one is of primary importance and the other nine are secondary substances (called predicates in modern parlance). They are the following (source):
   • (1) substance,
   • (2) quantity,
   • (3) quality,
   • (4) relation,
   • (5) where,
   • (6) when,
   • (7) being-in-a-position,
   • (8) possessing,
   • (9) doing or
   • (10) undergoing something or being affected by something
2. Substance and Predicates (secondary substances): a substance is what something is, and is that which other things are predicated of. For instance, Alice is a substance, and human is a predicate. Thus, we can make the proposition “Alice is human” where human has been predicated of Alice.
3. Essential and Accidental Properties: an essential property is one that a thing has to have in order to be what it is, whereas an accidental property is one that the object has only contingently. In other words, if the object ceased to have that property, it would remain the object that it is. For instance, a cup is something that has to be able to contain things, and so something like a hoola-hoop is not a cup because it lacks this essential property of being able to contain things. Having a handle, on the other hand, is an accidental property, since a cup can either have a handle or not have a handle.
4. Four Causes
   1. Material Cause: what the object is made out of
   2. Formal Cause: the form or structure of the object
   3. Efficient Cause: how the object came to be. Also our modern day kind of cause, such as the billiard ball picture, where a ball contacts another one and causes it to move
   4. Final Cause: the purpose of the object, i.e., what the object was made for (it’s functionality)
5. Logic
   1. We’ll begin with the laws of thought. While these were never expressed in this way by Aristotle, the medieval scholastic philosophers were able to identify these three, sometimes four, so-called laws of thought in Aristotle’s logic
      • Law of identity: things are identical with themselves
        • A = A
      • Law of non-contradiction: a proposition and its negation cannot both be true
        • not (A and not-A)
      • Law of excluded middle: either A must be true or not-A must be true
        • either A or not-A
      • Law of sufficient reason (disputable): everything must have a cause
   2. Now we will look at propositions and syllogisms. We’ll begin with Aristotle’s table of oppositions:

• Is & Are: these are what are called copulae, which link the subject and predicate. They are essentially words that broadly mean “to be”. We might say that “S is P” means something like “S being P” or “P = the way of being for S” or to get even worse in our grammar “S be’s P”
  • The ‘A’ proposition, the universal affirmative: ‘every S is a P’
    • In logic, if there is only 1 thing in the category, then that 1 thing is exhaustive and therefore counts as all. In other words, to say that “Socrates is P” is like saying “all of Socrates is P” since referring to Socrates exhausts everything in the category of “Socrates” (assuming we know by context that our referent is Socrates, the well-known Greek philosopher, that we’re talking about, but getting into how we fix our reference will bring us too far afield at this point).
  • The ‘E’ proposition, the universal negative: ‘no S are P’
  • The ‘I’ proposition, the particular affirmative: ‘some S are P’
    • In logic, the word some means any amount that isn’t zero or all. It could be read as “at least one S are/is P”
  • The ‘O’ proposition, the particular negative: ‘some S are not P’
• Contradictory propositions possess opposite truth-values.
• Contrary propositions cannot both be true.
• The relationship of subalternation results when the truth of a universal proposition, “the superaltern,” requires the truth of a second particular proposition, “the subaltern.”
• Subcontrary propositions cannot both be false.
• Syllogisms: there are two premises of the above A, E, I, or O forms. If the syllogism is valid, then the conclusion is guaranteed if the premises are true. If the syllogism is sound, then the premises are true and the syllogism is valid, and so the conclusion is both true and guaranteed. All valid syllogisms must have at least one universal premise. A syllogism takes the following form:
  • • Major premise
    • Minor premise
    • Conclusion
  • Syllogism Example:
    • All S is P
    • X is S
    • ∴ X is P
• Moods: with the four types of proposition and three propositional positions (major premise, minor premise, and conclusion) there are 256 possible syllogisms. There are, however, only 24 valid syllogisms, which are often divided into four “figures” based on the placement of the minor premise and are the following (parenthetical ones are known as weakened moods and derive particular conclusions from two universal “all” or “none” premises):
  • First figure: AAA, EAE, AII, EIO, (AAI), (EAO).
  • Second figure: AEE, EAE, AOO, EIO, (AEO), (EAO).
  • Third figure: AAI, EAO, AII, EIO, IAI, OAO.
  • Fourth figure: AAI, AEE, EAO, EIO, IAI, (AEO).

Aristotle was a rare genius who touched on just about every intellectual, scholarly topic. He was a biologist, performing many animal disections and mapping the anatomy of humans and numerous animals (many, famously, sent back by his pupil, Alexander the Great, during his conquest). Indeed, Aristotle’s anatomical work was used for over a millenium after his work.

In philosophy he also theorized about ethics, epistemology, aesthetics, politics, and numerous other areas. I will cover these in more detail in future edits of this post. For now it will suffice to say that his virtue ethics, with the golden mean, is still important in modern ethics. He also came up with the notions of eudaimonia and catharsis, which are still popular in ethics and aesthetics respectively. Needless to say, the works of Aristotle can fill (and has filled) a great many volumes.

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Ancient (323 B.C.E. – 400 C.E.)

Antisthenes (445 B.C.E. – 365 B.C.E.): Cynicism.

Mencius (372 B.C.E. – 289 B.C.E.): born Mèng Kē; or Mèngzǐ was a Chinese Confucian philosopher who has often been described as the “second Sage”, that is, after only Confucius himself. He is part of Confucius’ fourth generation of disciples. Mencius inherited Confucius’ ideology and developed it further.

Euclid of Alexandria (fl. Ca. 300 B.C.E.): Mathematician.

Zeno of Citium (332 B.C.E. – 262 B.C.E.): Early Stoicism.

Epicurus (341 B.C.E. – 270 B.C.E.): Epicureanism.

Nāgasena (ca 150 B.C.E.): the interlocutor in the Milinda Pañha

Marcus Tullius Cicero (106 B.C.E. – 7 December 43 B.C.E.): Orator and Philosopher.

Philo of Alexandria (ca. 20 B.C.E. – 40 C.E.): Hellnistic Jewish Philosopher. Perhaps best known for trying to harmonize the Torah with Greek philosophy. Although Jewish, much of his work is thought to have been an inspiration for Christian thought.

Seneca the Younger (4 B.C.E. – 65 C.E.): Roman Stoic philosopher, statesman, and dramatist.

1. Stoicism: Seneca’s teachings align with the core principles of Stoicism, which advocate for living in accordance with nature and reason, understanding that the only true goods are internal virtues like wisdom, justice, courage, and moderation. Everything external—wealth, health, fame—is considered indifferent, not truly contributing to happiness or the good life.
2. Rational Control and Emotion: Seneca emphasizes the importance of controlling one’s reactions and emotions through the use of reason. He believed that emotional suffering and disturbances result from incorrect judgments about the external world, which can be corrected by aligning one’s perspective with Stoic wisdom.
3. Tranquility and the Good Life: A central theme in Seneca’s philosophy is the pursuit of tranquility (ataraxia), a state of inner peace achieved by living virtuously and rationally, free from perturbations and in harmony with the universe. Seneca suggests that this state can be reached through practice, ethical living, and philosophical reflection.
4. Ethical Practices and Self-Improvement: Seneca advocates for continuous self-improvement through practices such as daily self-examination, reflection on one’s thoughts and actions, and reading and meditating on philosophical texts. He also encourages the cultivation of empathy, generosity, and fairness in interpersonal relationships.
5. Mortality and Death: Reflecting on death and mortality is another significant aspect of Seneca’s thought. He argues that contemplating death teaches us how to live, emphasizing that life’s brevity should inspire us not to waste time on trivial matters. Seneca’s letters and essays often advise how to face death with equanimity and dignity, viewing it as a natural, inevitable event that should neither be feared nor desired prematurely.
6. Fate and Providence: Seneca believes in the Stoic concept of providence, wherein everything happens according to a divine rational plan, and therefore, what happens is always, in some sense, for the best. Accepting fate — the logos or rational order of the universe — is crucial to achieving tranquility.

Jesus (Christ) of Nazareth (4 B.C.E. – 30 C.E.): Apocalyptic Jewish Prophet and Christian Messiah. There are literally thousands of books and other resources discussing, debating, and reinterpreting the “philosophy” of Jesus, but here I will lay out some of the aspects of his teachings that are broadly agreed upon (though even these each probably have plenty of critics who would disagree).

1. Kingdom of God: One of the central themes of Jesus’ teaching is the Kingdom of God. This concept, while multifaceted, generally refers to the reign or rule of God over all things. Jesus spoke of the Kingdom of God as both a present reality and a future promise, emphasizing that it is at hand and urging people to repent and believe in the gospel.
2. Love and Compassion: Jesus famously taught the importance of love and compassion. He summarized the entire Jewish law in two commandments: loving God with all one’s heart, soul, and mind, and loving one’s neighbor as oneself. He extended the definition of “neighbor” to include not just fellow countrymen but also strangers, enemies, and the marginalized, illustrating his teachings through parables like the Good Samaritan.
3. Forgiveness: Jesus emphasized forgiveness, teaching that individuals should forgive others, not just seven times, but seventy times seven times, symbolizing an unbounded forgiveness. He linked the forgiveness of sins to one’s willingness to forgive others, a principle highlighted in the Lord’s Prayer.
4. Peace and Nonviolence: Jesus promoted peace and nonviolence. One of his well-known teachings is to “turn the other cheek,” suggesting a non-retaliatory way of dealing with aggression. His message included loving one’s enemies and praying for those who persecute you, highlighting a radical approach to conflict and opposition.
5. Humility and Service: Jesus praised the virtues of humility and service over seeking power or privilege. He taught that “the last shall be first, and the first last” and demonstrated servanthood by washing his disciples’ feet, an act usually reserved for servants.
6. Justice and the Poor: Jesus had a special concern for the poor, marginalized, and oppressed. He criticized the hypocrisy and legalism of religious leaders who burdened people without lifting a finger to help them. He also spoke about the need for justice and right action rather than mere adherence to ritual.
7. Eschatological Warnings and Promises: Much of Jesus’ teaching included warnings about the coming judgment and the need for readiness. He described the final judgment as separating the righteous from the wicked based on their deeds of compassion and mercy towards the needy.
8. Salvation and Eternal Life: Central to Jesus’ teaching is the concept of salvation—deliverance from sin and its consequences. He offered himself as the way to eternal life, emphasizing faith in him and his sacrificial death and resurrection as the path to reconciliation with God.

Paul of Tarsus (5 B.C.E. – 64 C.E.): Jewish Apostle of Christ and Christian Evangelist. Quite possibly the most important person in the development of Christian thought. One of his biggest contributions was the notion that gentiles could become Christian. As with Jesus, there has been a lot of ink spilled on interpretations and reinterpretations of Paul.

1. Author of at least seven of the thirteen Pauline Epistles (Galatians, Romans, 1 Corinthians, 2 Corinthians, Philemon, Philippians, 1 Thessalonians), while three of the epistles in Paul’s name are widely seen as pseudepigraphic (1 Timothy, 2 Timothy, and Titus). Three others (2 Thessalonians, Ephesians and Colossians) are widely debated.

Epictetus (ca. 135 C.E.): Greek Stoic philosopher whose teachings are primarily preserved in the works “Discourses,” compiled by his student Arrian, and the “Enchiridion,” a concise manual of his core ideas. Born into slavery, Epictetus gained his freedom and established a school of philosophy in Nicopolis. His philosophy emphasizes ethics over theoretical questions and is centered on the practice of philosophy as a way of life.

1. Dichotomy of Control: One of the central tenets of Epictetus’s philosophy is the distinction between things that are within our control and things that are not. He argues that our own opinions, impulses, desires, and aversions are within our control, while external events—what happens to us—are not. True wisdom involves identifying this distinction and focusing our energy only on what we can control.
2. Inner Freedom and Serenity: Epictetus teaches that by focusing on our internal state and practicing self-control, we can attain freedom and tranquility. This inner serenity comes from accepting the external world as it is, rather than trying to control the uncontrollable. This acceptance allows us to endure pain, hardship, and misfortune without distress.
3. Role of Reason: For Epictetus, reason is a divine faculty that allows us to understand the world and our place within it. By using reason, we can align our desires with reality, act virtuously, and fulfill our role as rational beings. Living according to reason means living in harmony with nature and the universe, which is the essence of Stoic ethics.
4. Virtue as the Sole Good: Following Stoic principles, Epictetus holds that virtue—defined as the correct use of impressions—is the only true good. All other things typically regarded as goods, such as health, wealth, and reputation, are indifferent. They do not contribute to the goodness of our lives and should not be the focus of our desires or aversions.
5. Practical Wisdom: Epictetus emphasizes the practical application of philosophy. The “Enchiridion” provides specific advice for maintaining equanimity and ethical integrity in daily life. He encourages constant vigilance over one’s thoughts and actions to ensure they are in line with Stoic principles.
6. Resilience and Suffering: A significant part of Epictetus’s teaching is the idea that suffering arises from trying to control or desiring things that are inherently uncontrollable. By changing our expectations and reactions, we can overcome unnecessary suffering. He advocates for enduring suffering with dignity and viewing challenges as opportunities to demonstrate virtue.
7. Role of Relationships: Although Stoics are often thought of as detached, Epictetus underscores the importance of fulfilling social roles and responsibilities naturally and without emotional disturbance. He teaches that we should engage with others in a manner that is free from passion but full of love and fairness.

Marcus Aurelius (April 26, 121 C.E. – March 17, 180 C.E.): Late Stoicism.

Tertullian (155 C.E. – 240 C.E.): Christian Apologist and Theologian. Called “the father of Latin Christianity” and “the founder of Western theology.”

Origen of Alexandria (184 C.E. – 253 C.E.): Christian Apologist and Theologian.

1. His treatise On the First Principles (230 C.E.) systematically laid out the principles of Christian theology and became the foundation for later theological writings. It attempts to reconcile Christian doctrine with Greek philosophical traditions.
   1. Theology of the Godhead: Origen articulates a complex theological system that describes the nature of the Godhead. He posits a hierarchy within the Trinity, with the Father as the supreme principle, the Son (Logos) as emanating from the Father, and the Holy Spirit as proceeding from the Father through the Son. Despite this hierarchy, Origen emphasizes the unity and co-eternality of the Trinity, contributing to early Trinitarian theology.
   2. Logos Christology: Origen extensively discusses the Logos (Word), identifying Jesus Christ as the incarnate Logos who mediates between the transcendent God and creation. He argues that the Logos serves as a rational principle through which the universe was created and continues to be sustained.
   3. Creation and Cosmology: Origen proposes that God created the world from nothing (creatio ex nihilo), a doctrine that became central in later Christian theology. He describes creation as a fundamentally good act by a benevolent God, but he also introduces the notion that souls pre-existed their bodily existence and fell into material bodies as a result of sin.
   4. Universal Salvation and Apokatastasis: One of Origen’s more controversial teachings is the concept of apokatastasis, or universal restoration, in which he speculates that all creatures, including the devil and fallen souls, might eventually be restored to their original purity and reunited with God. This view was later deemed heretical by many Church authorities.
   5. Allegorical Interpretation of Scripture: Origen is known for his allegorical approach to biblical exegesis. He argues that Scripture contains multiple levels of meaning: the literal, the moral, and the spiritual (or allegorical). This method allowed Origen to interpret difficult or problematic passages in ways that were consistent with his theological system.
   6. Free Will and Predestination: Origen maintains a strong belief in human free will while also discussing God’s foreknowledge and predestination. He navigates these topics by suggesting that God’s foreknowledge does not constrain human freedom, positing that foreknowledge is not causative.
   7. Role of Prayer and Asceticism: Origen emphasizes the importance of prayer, ascetic practices, and moral striving in the Christian life. He believes that through prayer and self-discipline, Christians can progress spiritually and come closer to God.

Plotinus (204 C.E. – 270 C.E.): Neoplatonist. Sought to synthesize Plato’s teachings with a profound mystical and spiritual interpretation. His work, primarily recorded in the “Enneads” by his student Porphyry, is marked by its depth and complexity, addressing metaphysics, epistemology, and ethics.

1. The One: At the top of Plotinus’ metaphysical system is the One, also known as the Good. The One is beyond all categories of being and non-being, transcending all existence and thought. It is the ultimate source of all reality, and its nature is such that it cannot be described or comprehended by rational thought. The One is perfect unity and the cause of all that exists without being affected or diminished by its emanations.
2. Emanation: Plotinus introduced the concept of emanation to describe how everything else derives from the One. This is not a creation as in making something from nothing, but an overflowing of its essence. Below the One is the Intellect (or Divine Mind), where all Forms (ideal archetypes) exist. The Intellect contemplates the One and itself, producing a realm of real beings and structures. Below the Intellect is the Soul, which links the spiritual and material worlds. Souls emanate from the Intellect, and individual souls emanate from a World Soul.
3. The World Soul and Nature: The World Soul, according to Plotinus, is responsible for the life and order of the physical universe. It animates all living things and embeds the Forms into matter, crafting the sensory world. This process is both an act of creation and an expression of the Soul’s contemplative nature, mirroring the activity of the higher realm of the Intellect.
4. The Ascent of the Soul: A central theme in Plotinus’ philosophy is the soul’s potential to return to the divine, transcending the material realm and its own lower nature. This ascent involves ethical purification, intellectual development, and ultimately mystical contemplation. The soul’s journey back to the One requires a retraction of consciousness from the external world and a turning inward, culminating in a mystical union with the divine, which transcends normal modes of knowing.
5. Ethics and the Good Life: For Plotinus, the ethical life is a necessary preparation for the mystical ascent. Virtue is defined as a life lived in accordance with the Intellect. The virtues purify the soul, free it from passions, and prepare it for the return to the divine. Plotinus emphasizes the inner disposition and the alignment of one’s life with the Good rather than adherence to a set of external actions.

Porphyry of Tyre (234 C.E. – 305 C.E.): Neoplatonist. Extends Plotinus’ ideas while also introducing his own interpretations and systems, particularly in logic, metaphysics, and ethics.

1. Hierarchy of Beings: Like Plotinus, Porphyry structured reality in a hierarchical framework, with the One at the top, followed by the Intellect, and the Soul. Porphyry expanded on these ideas, giving more details about the intermediary beings and the process of emanation between these levels. His system also includes a more elaborate categorization of souls and their progression.
2. Problem of Universals: Porphyry is perhaps best known for his contributions to the problem of universals, which he outlined in his introduction to Aristotle’s “Categories,” known as the “Isagoge.” He posed the famous Porphyrian Tree which discusses whether categories (genera and species) are real and exist independently of the mind, or whether they exist only when thought of. This work became a fundamental text in medieval scholastic philosophy, influencing debates about universals for centuries.
3. Philosophy and Religion: Porphyry integrated religious elements more explicitly into his philosophical system compared to Plotinus. He was deeply interested in the role of religion in philosophical practice and wrote extensively on theurgy, rituals, and mysteries, seeing them as paths to spiritual ascent and union with the divine.
4. Ethics and Vegetarianism: Ethically, Porphyry advocated for a lifestyle that promoted purification and ascent of the soul. Notably, he argued for vegetarianism, believing that abstaining from animal food contributes to the purity of the soul and avoids the violence that stains the soul, which is counterproductive to spiritual progress.
5. Works on Logic and Philosophy: Beyond his metaphysical and ethical writings, Porphyry made significant contributions to logic and philosophy. His work included commentaries on Aristotle’s logic, which were crucial in transmitting Aristotelian logic to later generations. His own philosophical works also addressed a wide range of other topics, reflecting his broad intellectual pursuits.
6. Critique of Christianity: Porphyry was also a critic of Christianity, writing against the religion in his work “Against the Christians,” which was ordered to be burned in 448 AD and survives only in fragments. His criticisms were based on his philosophical beliefs and his view of Christianity as intellectually and morally inferior to pagan philosophy.

Athanasius of Alexandria (298 C.E. – 373 C.E.): Christian theologian and the 20th pope of Alexandria (Coptic Christianity). Chief proponent of Trinitarianism against Arianism. Attended the first Council of Nicaea.

1. On the Incarnation: This is one of Athanasius’ most famous and influential works, where he articulates the reasons and necessity for the Word (Logos) becoming flesh in Jesus Christ. He explains that Christ’s incarnation was essential for the redemption and salvation of humanity, emphasizing the defeat of corruption and death through His resurrection. The work is celebrated for its clear and profound theology, explaining the divine nature of Christ and His role in the restoration of human nature.
2. Against the Heathens: Often paired with “On the Incarnation,” this work argues against paganism and criticizes non-Christian religions and philosophies. Athanasius presents Christianity as the fulfillment and truth towards which all earlier religions were reaching. He critiques the moral and logical failures of pagan practices, setting the stage for his exposition on Christian doctrine in “On the Incarnation.”
3. Letters Concerning the Arian Controversy: Athanasius wrote numerous letters defending the Nicene Creed against Arianism, a theological doctrine that denied the full divinity of Jesus Christ. His letters, especially those concerning his multiple exiles due to his opposition to Arianism, detail his theological arguments and his struggles to uphold Nicene orthodoxy.

Council of Nicaea (325 C.E.): Its main accomplishments were settlement of the Christological issue of the divine nature of God the Son and his relationship to God the Father, the construction of the first part of the Nicene Creed, establishing uniform observance of the date of Easter, and promulgation of early canon law.

First Council of Constantinople (381 C.E.): repudiated Arianism and Macedonianism, declared that Christ is “born of the Father before all time”, revised the Nicene Creed in regard to the Holy Spirit (procession from the Father).

Hypatia (Ca. 360 C.E. – 415 C.E.): philosopher, mathematician, and astronomer who lived and taught in Alexandria, Egypt. She was one of the last great thinkers of ancient Alexandria and a prominent figure in the Hellenistic intellectual tradition. Hypatia’s philosophy combined elements of Neoplatonism, a school of thought that emphasized the role of intellect and contemplation in reaching a higher understanding of the cosmos and the divine.

1. Neoplatonism: Hypatia was a follower of Neoplatonism, the school of philosophy founded by Plotinus. Neoplatonists believed in the existence of a single, transcendent One from which all existence emanates. For them, the goal of philosophy was to understand the nature of the One and to achieve a mystical union with it through intellectual purification and contemplation.
2. Intellectualism and Rationality: Hypatia is known for her dedication to logic, reasoning, and the sciences as pathways to understanding the universe. She taught mathematics, astronomy, and philosophy, emphasizing the importance of rational thought and empirical knowledge.
3. The Ethical Application of Philosophy: Although specific details of Hypatia’s ethical teachings are sparse, her life and work suggest a commitment to the Neoplatonic view that living a virtuous, rational life is essential to philosophy. This includes the pursuit of knowledge and the development of personal virtues such as wisdom, courage, and temperance.

Augustine of Hippo (November 13, 354 C.E. – August 28, 430 C.E.): Christian Theologian. One of the most influential Christian philosophers, he is still often considered an authority on many issues important to the faith.

1. Epistemology: Augustine was a Platonist when it came to knowledge. For Plato, knowledge of the forms came from our prior acquaintance with them before life – the knowledge was already buried deep within ourselves, recoverable through the use of reason. Augustine thought that knowledge came through personal intellectual insight. But, the possibility of such an insight was conditioned on God.
   • Augustine actually came up with a formulation of Descartes’s “I think therefore I am” a millennium earlier. Wanting to stave off skepticism, Augustine came up with the following indubitable sources of knowledge (source):
     1. the certainty of self-referential knowledge (the wise person “knows wisdom”, Contra Academicos 3.6; the Academic skeptic “knows” the Stoic criterion of truth, ib. 3.18–21);
     2. the certainty of private or subjective knowledge (I am certain that something appears white to me even if I am ignorant whether it is really white, ib. 3.26);
     3. the certainty of formal, logical or mathematical, structures (ib. 3.24–29), knowledge of which is possible independently of the mental state of the knower, whereas the reliability of sense impressions differs according as we are awake or dreaming, sane or insane.
2. The Soul: the immortality of the soul can be proven, according to Augustine, though his proof is not a very good one. He says that “since truth is both eternal and in the soul as its subject, it follows that soul, the subject of truth, is eternal too” and says “that soul is immortal because of the inalienable causal presence of God (= Truth) in it” (source). What is interesting, however, is that even though Augustine thought the soul was incorporeal and could persist outside the body, he thought that the soul preferred to be embodied and that the soul would be reunited with the body at the end of time (this was pretty typical back then as most Christians and Jews of the time thought that the final kingdom of God would be here on earth).
3. Grace and Original Sin: probably the biggest impact that Augustine has on modern Christianity, however, are his concepts of Grace and Original Sin. The latter says that all humans are born with original sin, a sinful nature that they are born with instead of due to something they have done. Indeed, it is this original sin that makes it impossible for humans to do any good at all. All humans, therefore, deserve punishment. But, due to the Grace of God through Christ, which restores humanity’s ability to do good works, some humans will be saved. I say some because Augustine was a proponent of predestination, i.e., that some people were “elected” by God prior to their creation to be saved from the damnation that all humans deserve. This is fine, according to Augustine, because, as I said, he thought all humans deserved eternal damnation, so it is actually a demonstration of God’s grace to save even a handful of them.
4. City of God: according to Augustine, history is driven by the celestial battle of good vs. evil. The Catholic church (the eponymous City of God) fights on the side of good against evil. Therefore, any government that aligns itself with the Catholic church is fighting on the side of good. This book was written in response to the 410 C.E. sack of Rome by the Visigoths, which was blamed by some on Rome’s abandoning its old Pagan religion. Augustine disagreed, saying that Rome’s success was due to aligning with the Catholic church and making Christianity the religion of the Empire. Furthermore, the success of Rome would continue in the afterlife, which was much more important than the goings-on of the physical world.

Council of Chalcedon (451 C.E.): Its most important achievement was to issue the Chalcedonian Definition, stating that Jesus is “perfect both in deity and in humanness; this selfsame one is also actually God and actually man” (Dyophysitism). The council’s judgments and definitions regarding the divine marked a significant turning point in the Christological debates.

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Late Antiquity (400 C.E. – 800 C.E.)

Pseudo-Dionysius the Areopagite (Late 400’s C.E. – Early 500’s C.E.): Christian Theologian. His integration of Neoplatonism with Christian dogma created a theological framework that emphasized the transcendence and unknowability of God, the spiritual hierarchy of the universe, and the potential for direct mystical engagement with the divine. His works, particularly “The Divine Names,” “The Mystical Theology,” and “The Celestial Hierarchy,” have had a lasting impact on both Eastern Orthodox and Western Christian mystical traditions. His thought influenced later mystics such as Meister Eckhart and St. John of the Cross, as well as contributing to the development of scholastic theology in the Middle Ages.

1. Apophatic Theology (Negative Theology): Pseudo-Dionysius emphasized that God transcends all human understanding and language. According to his apophatic theology, the best way to approach the divine is through negation—understanding what God is not, rather than what God is. This means that God’s essence is beyond all categories of being and non-being, and cannot be adequately described by human language.
2. Mystical Union with God: He believed in the possibility of a direct, personal union with the Divine, which can be achieved through contemplation and the stripping away of all material concerns and conceptual thoughts. This mystical approach involves a deepening inward journey to reach the “Divine Darkness,” where one experiences the presence of God beyond all sensory and intellectual understanding.
3. Hierarchical Cosmos: Pseudo-Dionysius outlined a detailed hierarchy of celestial beings and ecclesiastical orders, reflecting his view that the universe is structured in a complex hierarchy that mirrors the order and harmony of the Divine. His celestial hierarchy includes different orders of angels, from seraphim and cherubim to archangels and angels, each with specific roles in the divine order.
4. Theurgy and Liturgy: He saw liturgical practices as a form of theurgy, meaning that sacred rites and ceremonies could help elevate the soul towards God. This connection between liturgical practice and mystical theology emphasizes the transformative power of the Eucharist and other sacraments in achieving communion with God.

Boëthius (477 C.E. – 524 C.E.): Christian Theologian.

1. God’s prescience of the future is not a contradiction with free will because for humans, future events are contingent (the outcome is not fixed) but from God’s point of view as an eternal being, they are.
   • God’s eternity ‘is the complete, simultaneous, and perfect possession of unending life.’ The past, present, and future are all experienced as the present from God’s point of view. Freedom happens in the present, therefore freedom is conserved even if God is present to our future.

Proclus Lycaeus (February 8, 412 C.E. – April 17, 485 C.E.): Pagan Neoplatonist Philosopher.

Muhammad (570 C.E. – June 8, 632 C.E.): Prophet of Islam. Muhammad is considered by Muslims to be the last prophet sent by God to mankind. His teachings are recorded primarily in the Quran, which Muslims believe is the literal word of God as revealed to Muhammad, and in the Hadith, collections of sayings and actions attributed to Muhammad.

1. Monotheism (Tawhid): The core of Muhammad’s message is the emphasis on monotheism—the belief in the oneness of God (Allah in Arabic). He preached against the polytheistic practices prevalent in Arabia at the time and emphasized that Allah is the only deity worthy of worship. This principle is encapsulated in the Shahada, the Islamic declaration of faith: “There is no god but Allah, and Muhammad is His messenger.”
2. The Quran: Muhammad’s revelations, which he received over the course of approximately 23 years, are compiled in the Quran. The Quran covers a wide range of topics, including theology, morality, guidance for personal conduct, and legal principles. Muslims believe the Quran to be the final and complete revelation and a correction of previous scriptures such as the Torah and the Bible.
3. Prophethood: Muhammad is regarded as the “Seal of the Prophets,” which means he is considered the last in a long line of prophets sent by God, which includes figures like Abraham, Moses, and Jesus. The role of the prophet, in Islamic thought, is to guide humanity according to God’s will.
4. Ethical and Moral Conduct: Muhammad’s teachings strongly emphasize moral and ethical conduct. Principles such as honesty, generosity, justice, and compassion for the poor and needy are recurrent themes in his teachings. He also stressed the importance of family bonds, good neighborliness, and fair business practices.
5. Community and Ummah: Muhammad established a tightly knit community of followers in Medina, which served as a model for the ummah, the global community of Muslims. He set forth guidelines for social and political conduct within this community, including the rights and responsibilities of individuals and leaders. The Constitution of Medina, a document created under his leadership, is one of the earliest examples of a formal agreement between different religious and tribal groups, emphasizing coexistence and mutual obligations.
6. Legal and Judicial Reforms: Muhammad introduced a number of reforms to the legal practices of his time, including rights for women in marriage, divorce, and inheritance. He also reformed aspects of the penal system, emphasizing justice tempered with mercy, and the importance of intention in judging actions.
7. Jihad: In the context of Muhammad’s teachings, jihad refers to “striving” or “struggling” in the way of God. While often interpreted in the context of self-defense, the broader and more significant meaning involves struggling against sin, striving for moral self-improvement, and spreading the teachings of Islam through peaceful means.
8. Eschatology: Muhammad’s teachings include detailed descriptions of the afterlife, including the Day of Judgment, heaven (Paradise), and hell. These teachings are meant to guide believers towards moral and righteous living, with the promise of heavenly rewards and warnings of punishment for wrongdoing.

Third Council of Constantinople (680/681): Condemned monoenergism and monothelitism as heretical and defined Jesus Christ as having two energies and two wills (divine and human).

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Medieval (800 C.E. – 1600 C.E.)

Al-Kindī (801 C.E. – 873 C.E.): Islamic Theologian.

Al-Fārābī (872 C.E. – 950 C.E.): Islamic Theologian.

1. Ten levels of intelligence, emanating from God, the First Cause, down the concentric spheres to the lowest intelligence, the Agent Intellect (has no sphere of its own), which bestows form to matter and lets humans understand universals.
   1. Plotinian emanational cosmology.
   2. God’s principle activity is self-contemplation. This thinking “overflows” into the second intellect and so on down to the physical world.
2. Ethics: based on Plato’s Republic. The rulers should be philosophers/imams who have gained access to the Agent Intellect (rather than Plato’s philosopher kings who have gained access to the Ideas).

John Scotus Eriugena (815 C.E. – 877 C.E.):

Al-Ash’ari (874 C.E. – 936 C.E.): Islamic Theologian.

Ibn Sina aka Avicenna (980 C.E. – 1037 C.E.): Persian Islamic Theologian.

1. Realist in terms of universals: particular things have a nature that we base our concepts on. For example, a horse has some nature – it’s horseness – and I base my conception of horse on that nature. But the nature – the horseness – is not a thing; it is not a subject for predication, such that the question of whether ‘horseness’ is one or not one is incoherent (solving the problem of having one thing (the universal) be fully present in multiple things (the particulars)).
2. Accepts Al-Fārābī’s Plotinian emanational cosmology.
3. Metaphysics and God: Avicenna developed a distinctive metaphysical framework. At the center is the concept of the Necessary Existent (God), who is the ultimate cause of all existence. God, as the only necessary being, exists independently, whereas all other beings are contingent and derive their existence from Him through a process of emanation. This idea elaborates on the Neoplatonic themes found in the works of Plotinus and Proclus.
4. Theory of the Intellect: Avicenna posited a complex hierarchy of intellects, culminating in the Active Intellect, which plays a critical role in human cognition. According to Avicenna, the Active Intellect is a transcendent source that endows human minds with the forms or universals needed to comprehend the material world. This engagement facilitates not only human understanding but also the soul’s potential ascent back to the divine.
5. Epistemology: Avicenna made significant contributions to the theory of knowledge. He argued that all human knowledge begins with perception, which is then abstracted into concepts by the intellect. He is famous for his “floating man” thought experiment, which seeks to demonstrate the existence of the soul as a self-aware entity independent of the body, highlighting the soul’s awareness of itself even in the absence of external sensory inputs.
6. Philosophy of Science and Medicine: In science and medicine, Avicenna extended his philosophical theories into practical domains, arguing that empirical investigation and rational analysis must work hand-in-hand. His “Canon of Medicine” was a monumental work in the field, serving as a standard medical text in both the Islamic world and Europe for centuries.
7. Ethics and the Soul: Avicenna’s ethical views emphasize the development of virtues through rational reflection and the cultivation of the soul’s knowledge. The ultimate ethical aim is to achieve a state of intellectual and spiritual perfection, leading to the soul’s union with the Divine, echoing the Neoplatonic pursuit of returning to the source.
8. Existence and Essence: Another major contribution of Avicenna to philosophy is his distinction between essence and existence in created beings. In his framework, existence is an accidental attribute of an essence (the nature of a thing), which is a key departure from the Aristotelian positions and influenced later medieval thinkers, including Thomas Aquinas.

Catholic-Orthodox Christian Schism (1054 C.E.): The immediate cause of the schism was the mutual excommunications in 1054. Pope Leo IX sent a delegation led by Cardinal Humbert to Constantinople to deal with the issues concerning the use of unleavened bread in the Eucharist and other matters. The mission failed to achieve reconciliation and ended with Humbert excommunicating Patriarch Michael Cerularius of Constantinople, who, in turn, excommunicated the papal delegates. Although these excommunications were later lifted in 1965, they symbolized the deep-seated rift that had developed. Other causes are often said to be the following:

1. Filioque: It is not in the original text of the Creed, attributed to the First Council of Constantinople (381), the second ecumenical council, which says that the Holy Spirit proceeds “from the Father”, without additions of any kind, such as “and the Son” or “alone”. In the late 6th century, some Latin Churches added the words “and from the Son” (Filioque) to the description of the procession of the Holy Spirit, in what many Eastern Orthodox Christians have at a later stage argued is a violation of Canon VII of the Council of Ephesus, since the words were not included in the text by either the First Council of Nicaea or that of Constantinople. This was incorporated into the liturgical practice of Rome in 1014, but was rejected by Eastern Christianity.
2. Ecclesiastical Authority and Jurisdiction: There was a long-standing disagreement over the extent of the authority of the Bishop of Rome (the Pope). The Western Church viewed the Pope as the supreme spiritual authority, derived from his status as the successor to Saint Peter, whom they considered the first bishop of Rome. The Eastern Church, however, regarded the Pope as merely first among equals, a primacy of honor more so than of absolute authority, and resisted Papal claims to jurisdiction over the entire Christian Church.
3. Political Factors: The political division between the Eastern and Western parts of the Roman Empire (formally divided in 395) contributed to the schism. The fall of the Western Roman Empire in the 5th century and the continuation of the Eastern Roman (Byzantine) Empire intensified these divisions. Political conflicts, especially leadership disputes and differences in imperial and ecclesiastical alliances, exacerbated ecclesiastical disagreements.
4. Cultural and Linguistic Differences: Cultural and linguistic divergences also played a significant role. Latin was the language of the Church in the West, while Greek was used in the East. Over time, this linguistic division came to reflect deeper cultural and theological differences, making communication and mutual understanding increasingly difficult.
5. Liturgical Differences: Variations in liturgical practices also contributed to the growing divide. Differences over clerical celibacy (priests in the Western Church were required to be celibate, whereas in the Eastern Church they were not), the use of unleavened bread in the Eucharist in the West, and other ritualistic differences highlighted the distinct identities of the two traditions.

Saint Anselm of Canterbury (1033 C.E. – 1109 C.E.): Christian Theologian.

1. His biggest claim to fame is probably his ontological argument for the existence of God. It goes like this:
   1. By definition, God is a being than which none greater can be imagined.
   2. A being that necessarily exists in reality is greater than a being that does not necessarily exist.
   3. Thus, by definition, if God exists as an idea in the mind but does not necessarily exist in reality, then we can imagine something that is greater than God.
   4. But we cannot imagine something that is greater than God.
   5. Thus, if God exists in the mind as an idea, then God necessarily exists in reality.
   6. God exists in the mind as an idea.
   7. Therefore, God necessarily exists in reality.

Al-Ghazālī (1058 C.E. – 1111 C.E.): Sufi Islamic Kalam Theologian.

Peter Abelard (1079 C.E. – 1142 C.E.): Christian Theologian.

1. First to defend nominalism (as opposed to realism) in regards to the question of universals: he said that universals are nothing but words, not actual things. Words ‘nominate’ (refer to) things in the world while also ‘signifying’ things by producing the concept in a person’s mind. Universal words do not nominate universal things but nominate all the particular things which fall under them – universals nominate how particulars come together (e.g., under the status of ‘horse’).

Gilbert of Poitiers (1085 C.E. – 1154 C.E.): Christian Theologian.

Ibn Tufayl (1105 C.E. – 1185 C.E.): Andalusian Sufi Muslim Polymath.

Ibn Rušd aka Averroes (1126 C.E. – 1198 C.E.): Andalusian Islamic Theologian. He had a profound influence on medieval philosophy, especially in the Latin West, where his works ignited the Averroism movement among scholars in medieval Europe. His interpretations of Aristotle were pivotal in shaping the intellectual landscape of the Middle Ages and the Renaissance, particularly influencing figures such as Thomas Aquinas and later Scholastic philosophers.

1. A single possible intellect for all humans: that which individuates things is bodily, but the possible intellect is not bodily, so it must be unindividuated. Therefore, there is only one intellect shared by all humans. That’s why when person A and person B learn astronomy, they learn the same
   • The object is to the sense organ what the imaginative form of the universal is to the possible intellect; the Agent Intellect is analogous to the light shining on the object. The imaginative form of the universal is mine even if the possible intellect is shared by all humans, therefore we do not all share the same thoughts.
2. Rejects Al-Fārābī’s Plotinian emanational cosmology. There is a First Mover and intelligences which move the celestial spheres, but only because they desire for the most perfect being. The Agent Intellect does not give forms to the physical (sublunar) world, but is used only for rendering universals in the possible intellect.
3. Harmony of Religion and Philosophy: One of Averroes’ central tenets was the compatibility of religion and philosophy. He argued that both the Quran and philosophy pursue the truth, and therefore they cannot ultimately contradict one another. Wherever they seem to conflict, interpretation must reconcile them, with philosophy interpreting the hidden meanings of scripture.
4. Aristotelianism and Rationalism: Averroes is often regarded as one of the most influential Aristotelian philosophers of his time. He wrote extensive commentaries on nearly all of Aristotle’s works, aiming to restore the true ideas of Aristotle after centuries of what he saw as misinterpretation by earlier scholars, particularly in the Christian and Islamic worlds. He emphasized the use of reason and was particularly interested in Aristotle’s works on logic, metaphysics, and ethics.
5. Theory of the Intellect: Averroes proposed a controversial theory known as the “unity of the intellect,” suggesting that all humans share a single separate intellect, a universal Agent Intellect. This theory posits that while individual souls are endowed with a ‘potential intellect’ capable of rational thought, the ‘active intellect’ is a transcendent and impersonal force that actualizes human thought. This idea faced criticism for seeming to undermine personal immortality and individual responsibility.
6. Natural Philosophy: In the realm of science and natural philosophy, Averroes affirmed the importance of empirical observation and rational analysis. He believed that philosophical inquiry could lead to a deeper understanding of the natural world and supported the use of Aristotelian physics and metaphysics to explain natural phenomena.
7. Ethics and Law: Averroes was also a judge and an expert in Islamic jurisprudence. His ethical and legal writings reflect a commitment to justice and rational analysis in the interpretation of Sharia (Islamic law). He believed that ethical and legal norms should promote the well-being of individuals and society, which resonates with Aristotelian virtue ethics.

Moses ben Maimonides (1135 C.E. – 1204 C.E.): Sephardic Jewish Theologian.

1. God’s Prescience: uses negative theology. When we talk about God, we can’t apply the human meanings of words used to describe Him (human language is used equivocally when talking about God). That means when we say God ‘knows’ contingent future events, we don’t actually understand what that means as it pertains to God. This leads to his formulation of the “via negativa” approach to discussing God, focusing on stripping away human attributes from God rather than attributing human qualities to the divine.
2. Guide for the Perplexed: This is Maimonides’ most famous philosophical work, written for Jews who were well-educated in philosophy and science but found themselves perplexed by apparent contradictions between Torah teachings and rational thought. In this work, Maimonides seeks to harmonize and reconcile Hebrew Scripture with Aristotelian philosophy, advocating for a rational approach to understanding religious texts.
3. Ethics and the Law: Maimonides placed a strong emphasis on ethics, which he saw as deeply embedded in the Jewish law (Halakha). He believed that the purpose of the law was to perfect the soul, helping individuals to cultivate moral virtues and intellectual abilities. His “Mishneh Torah,” a comprehensive code of Jewish law, also reflects his systematic approach to ethics, law, and daily life.
4. Rationalism and Faith: Maimonides was a staunch rationalist, believing that reason and faith are not only compatible but also mutually reinforcing. He argued that true understanding of God and the Torah requires the use of reason, and that philosophical inquiry can lead to a deeper understanding of divine truths. He maintained that conflicts between reason and scripture typically arise from misunderstandings of scripture, which should be interpreted in the light of rational evidence.
5. The Messiah and Resurrection: While Maimonides’ approach to many theological topics was marked by rationalism, he also upheld traditional Jewish beliefs in the coming of the Messiah and the resurrection of the dead. These beliefs, he posited, should be understood and accepted as fundamental components of Jewish faith.
6. Influence on Jewish and Non-Jewish Thought: Maimonides’ works had a lasting impact on Jewish theology and were instrumental in shaping the subsequent development of Jewish thought. His ideas also influenced Christian and Islamic philosophers, demonstrating the broad reach of his rationalist and ethical perspectives.

Shahāb ad-Dīn” Yahya ibn Habash Suhrawardī (1154 C.E. – 1191 C.E.): Persian Islamic Theologian.

Fakhr al-Dīn al-Rāzī (1150 C.E. – 1210 C.E.): Persian Sunni Islamic Theologian.

Ibn Arabi (July 26, 1165 C.E. – November 16, 1240 C.E.): Andalusian Islamic Theologian.

Saint Thomas Aquinas (1225 C.E. – March 7, 1274 C.E.): Christian Theologian.

1. If Aquinas had one lasting impact on western philosophy, it would be in popularizing Aristotle in European philosophy and theology. Prior to Aquinas, the European philosophers were much more Platonic in their ethos, while the Arabic philosophers were more Aristotelian. Aquinas was deeply Aristotelian, offering incisive commentaries on Aristotle’s works and adopting much or Aristotle’s philosophy into his own. With Aristotle’s more worldly philosophy, this made what is called natural theology a much more prominent part of the European Christian tradition.
2. The second thing that Aquinas is most known for are his “Five Ways” which are five arguments for the existence of God. I will give a brief overview of these five arguments here.
   • (1) Unmoved Mover: a movement (whether in the usual sense of a moving object or as a movement from potentiality to actuality) must be moved by something else. Since there cannot be an infinite regress, there must be an unmoved mover. God is that unmoved mover.
   • (2) First Cause: nothing can cause itself, because then it would have to have been prior to itself, which is a contradiction. That means everything has a cause external to it. But again there cannot be an infinite regress, so there must be something that was not cause, i.e., a first cause. God is that first cause.
   • (3) Contingency: if it is possible for something to exist, then it is also possible for it not to exist. But if everything was contingent (merely possible instead of necessary) then nothing would exist. Therefore there must be something that exists necessarily. God is that necessary thing.
   • (4) Degree: things like love, justice, mercy, holiness, and so on all exist to different degrees in the things that exist. But, just like in a room full of people with varying degrees of height, one of them must be the tallest. Therefore there must be something that has the most of all those things (love, justice, etc.). God is that which has the highest degree of all those things.
   • (5) Final Cause: the world proceeds by regular, reliable, and predictable laws. Since matter has no intelligence of its own, it could not have given itself this regularity on its own. Therefore there must be an intelligence that gave matter its reliable nature. God is that intelligence.
3. Aquinas rejects Averroes’s idea of the Agent Intellect. Says it’s like an eye (the Agent Intellect) looking at a colored (imaginative universal) wall (the possible intellect) and the colored wall somehow seeing the color. Says instead that the human soul is itself intellective and is the substantial form of the human body; intellectual reasoning, unlike perceiving or imagining, requires no bodily organ and therefore the soul can exist independent of the body.
4. Accepts Boëthius’s view of God’s prescience.

Dante Alighieri (1265 C.E. – 1321 C.E.): Italian Poet. He wasn’t a philosopher per se, but his depctions of Heaven, Hell, and Purgatory have been extremely influential as to our conceptions of them.

John Duns Scotus (1266 C.E. – 1308 C.E.): Christian Theologian.

1. Agreed with Avicenna on universals, but altered it somewhat. Said there are two sorts of unity: numerical unity and singularity (which is less than numerical). Horses have the same singular horseness, but this horseness is not numerically the same – in the same way that any white thing (not just a single white thing) is the opposite in color to a single black thing. It is a things haecceity – it’s thisness – that individuates things, ‘contracting’ the common nature into an individual.
2. For God’s prescience: God knows all the possible ways the entire existence of humankind could be, but he wills only one of them. God was free in that he could have willed existence to be otherwise, but is providential in that he does not change what he has

William of Ockham (1287 C.E. – 1347 C.E.): Christian Theologian.

1. Rejected Duns Scotus’s realism on universals (though he never read Abelard’s works). If A = horse1, B = horseness, and C = horse2, then A = B and C = B must mean that A = C and it’s absurd for horse1 = horse2.
2. Accepted Duns Scotus’s view on God’s prescience.

Levi ben Gershon aka Gersonides (1288 C.E. – 1344 C.E.): French Jewish philosopher.

1. God’s prescience: rejects Maimonides negative theology. If words applied to God don’t have the same meaning as when applied otherwise, anything can be applied to God by just saying the meaning is different for God.
   • Gersonides says God does not know particular events, but knows their providential order. God knows the reason for events, but not the particular outcome: using their intellects, humans can turn away from divine providence.
     • This was rejected by Gersonides’s contemporaries and successors since it contradicts God’s perfection by limiting God’s knowledge and providence.

Martin Luther (November 10, 1483 C.E. – February 18, 1546): German theologian

1. Famous for his 1517 C.E. ninety-five theses that sparked the protestant reformation. These theses famously called the Catholic church out for indulgences (paying the Catholic church in order to have punishment for sins reduced) and for arguing that salvation comes through a personal relationship with God instead of through the Sacraments of Penance.
2. Another of his lasting influences is the printing of the Bible into German. It was previously almost exclusively printed in Latin, which few people could read. Printing the Bible in a more common language made it available for many more people to read (and interpret) on their own. Making it so people did not have to go through the Catholic church to read and interpret the Bible rivals the ninety-five theses in importance.

Nicolaus Copernicus (February 19, 1473 C.E. – May 24, 1543 C.E.): Polish Renaissance polymath, mathematician, and astronomer

1. Most famous for coming up with the heliocentric model of the universe. This de-centering of the earth also famously demonstrated that humans were not as special as they once thought. This has come to be called the Copernican Principle, where a scientific hypothesis is supposed to avoid privileging humans in any special way.

Niccolò Machiavelli (May 3, 1469 C.E. – June 21, 1527 C.E.): Italian philosopher

Pietro Pomponazzi (September 16, 1462 C.E. – May 18, 1525 C.E.): Italian philosopher.

1. Criticizes Aquinas’s view of the soul – how can intellective soul be form of the body and still live independently of it? How can they be individuated if individuation is by matter?
   1. Says the soul does not survive human death – no reward or punishment. Being virtuous ought to be for virtue itself, not a reward after death, which makes it less virtuous.
   2. Though he defends his position, he accepts Aquinas’s view of immortality anyway – reason cannot answer the question, so one must turn to faith.

John Calvin (Jean Cauvin) (July 10, 1509 C.E. – May 27, 1564): French theologian, pastor, and reformer in Geneva.

1. Sensus Divinitatis (“sense of divinity”): “That there exists in the human mind and indeed by natural instinct, some sense of Deity [sensus divinitatis], we hold to be beyond dispute, since God himself, to prevent any man from pretending ignorance, has endued all men with some idea of his Godhead…. …this is not a doctrine which is first learned at school, but one as to which every man is, from the womb, his own master; one which nature herself allows no individual to forget.”
2. Famous for his focus on predestination, which says that there are a certain number of people who are God’s elect. These elect are people who will go to heaven. Being elect is not something you can earn or lose, but is something you were predestined with.

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The Moderns

This section will things from Descartes to Immanuel Kant and then up to some of the important 19th century thinkers, like Karl Marx. As usual, making these kinds of demarcations can be somewhat arbitrary, but it’s useful for getting an understanding of the evolution of thought. Modern philosophy is often said to begin with Descartes, where philosophy transcended scholasticism, which was characterized by a sort of religious adherence to the ancients, whose wisdom was thought to be sacred. It was Descartes who wanted to move past the slavish adherence to Plato and especially Aristotle, though even most of these thinkers (including Descartes) didn’t move past most of the Platonic/Aristotelian presuppositions.

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Early Modern (1600 C.E. – 1800 C.E.)

Descartes (March 31, 1596 C.E. – February 11, 1650 C.E.): French philosopher.

1. Methodological Doubt: Descartes is famous for his extreme skepticism, which is somewhat ironic since what he had set out to do was try to find indubitable certainty. He thought that to do this he needed to doubt every possible thing that he could in order to find those things that could not possibly be doubted. From there, in a foundationalist epistemological formulation, he would be able to erect all the rest of knowledge on those indubitable, self-evident foundations.
2. You can think about it this way: if A and B are undoubtable, self-evident propositions, then they are certain knowledge. Now, if C, D, and E all are not self-evident, but indubitably follow from A and B, then I can be absolutely confident in C, D, and E as well. And then if F, G, H, I, and J all indubitably follow from some combination of A, B, C, D, and E, then I can be absolutely certain of those as well. And in this fashion, all knowledge can be regained with absolute certainty.
3. Evil Demon/Genius/Genie (depending on your translation): Descartes began by considering that even those things that seem obvious can be doubted. That I am seeing my computer screen in front of me can be doubted because it is not logically impossible that some evil demon is fooling me (in modern times, we often propose that we might be a brain in a vat or living in a simulation). My memories can be doubted because this evil demon may have implanted false memories in me. Everything can be doubted… except the fact that I am doubting. And if I am doubting, that means I am thinking. And if I am thinking, that means I must exist. Hence, Descarte’s famous “Cogito ergo Sum” – I think, therefore I am.
4. Descartes then proves to himself the existence of God using a formulation of the ontological argument. With certainty that God exists, and that God, being benevolent, would not fool him the way his evil demon would, Descartes then feels assured that the world exists.
5. Mind-Body Dualism: according to Descartes, the mind can doubt the existence of the body, but it cannot doubt its own existence. This means that the mind and body are separate substances. There is the immaterial mind (or soul) and the material body. He conjuctured that the immaterial soul could interact with the body through the pineal gland.

Francis Bacon (January 22, 1561 C.E. – April 9, 1626 C.E.): English philosopher. His works are seen as contributing to the scientific method and remained influential through the later stages of the scientific revolution.

Galileo Galilei (February 15, 1564 C.E. – January 8, 1642 C.E.): Italian astronomer and physicist

Thomas Hobbes (April 5, 1588 C.E. – December 4, 1679 C.E.): English philosopher

1. Leviathan: important work in the field of political philosophy and social contract theory. In this work, Hobbes outlines his views on the nature of human beings, the necessity of government, and the ideal form of political organization.
   1. State of Nature: Hobbes begins with the concept of the ‘state of nature’, a hypothetical condition in which humans exist without any form of government or social structure. In this state, humans are motivated by natural desires and their actions are guided by their own perceptions of good and evil. Hobbes famously describes the state of nature as a state where life is “solitary, poor, nasty, brutish, and short,” due to the inherent selfishness and aggression of human beings.
   2. Social Contract: To escape the anarchic state of nature, Hobbes proposes that individuals collectively agree to surrender their natural freedoms to an absolute sovereign. This agreement constitutes the social contract. By consenting to this arrangement, individuals gain security and protection from the constant fear of death and violence that prevails in the state of nature.
   3. Sovereignty: Hobbes argues for a form of absolute sovereignty as the only viable form of government capable of maintaining peace and order. The sovereign, whether a monarch or an assembly, holds unchecked authority over subjects to enforce laws and ensure peace. The power of the sovereign is not subject to the consent of the people after it is established, except in matters where the sovereign fails to provide security.
   4. Legitimacy of the Sovereign: The legitimacy of the sovereign’s power comes not from divine right or heredity but from the social contract itself. As long as the sovereign can protect those who have consented to the contract, his or her power remains legitimate. If the sovereign cannot provide protection, the agreement is void, and the people have the right to form a new government.
   5. Civil Society and Laws: Hobbes discusses the importance of laws within civil society, which are created not merely to restrain individuals but to guide them towards a peaceful and cooperative existence. Laws, according to Hobbes, should be designed as if all men were knaves, looking out for their own interests.
   6. Religion and Government: Hobbes also integrates the role of religion into his political framework, asserting that the sovereign has the authority to control religious practices in order to prevent discord and maintain social harmony.

John Locke (August 29, 1632 C.E. – October 28, 1704 C.E.): English philosopher

In what follows, quotes are all from Locke, except where stated otherwise. My main source for this has been The Cambridge Companion to Locke, edited by Vere Chappel.

1. Representational Theory: Locke posited Ideas as the representation of what someone is thinking about. He says in his Essay Concerning Human Understanding: “[Idea] being the Term which, I think, serves best to stand for whatsoever is the Object of the Understanding when a Man thinks, I have used it to express whatever is meant by Phantasm, Notion, Species, or whatever it is, which the Mind can be employ’d about in thinking.” And “whatsoever the Mind perceives in it self, or is the immediate object of Perception, Thought, or Understanding, that I call Idea.” This tells us that for Locke, the idea is a representation in the mind – they are the immediate objects of thought which mediate between objects in the world and our perceptions of them. This produces what critics call a “veil” between the perceiver and an external world, where we don’t have direct perception of the object, but instead must go through the intermediate step of the Idea.
   • Locke makes distinctions between simple and complex ideas, particular and general ideas, concrete and abstract ideas, adequate and inadequate ideas. The main one is that of simple and complex Ideas, which I’ll define further.
     • Simple Ideas: Locke says of simple Ideas that “being…in itself uncompounded, contains in it nothing but one uniform Appearance, or Conception in the Mind, and is not distinguishable into different Ideas.” In other words, there is no differentiation within a simple Idea, such as containing two different colors. Locke gives as examples of simple Ideas “Yellow, White, Heat, Cold, Soft, Hard, Bitter, Sweet” for sensations, but he also gives examples of “ideas of reflection” which are “Perception, Thinking, Doubting, Believing, Reasoning, Knowing, Willing, and all the different actings of our own Minds.” These two things, experience and reflection, are the only two sources of simple ideas for Locke, which is why he is considered an empiricist.
     • Complex Ideas: compositions of simple Ideas, where, for instance, an apple is a composition of color, shape, size, taste, rigidity, and so on. These complex ideas actually inhere in the object, they are not put together by the mind, and so perceiving them is a passive process. However, the mind can take simple Ideas that it has experienced in the past and “compound” them into complex ideas in the imagination.
       • Complex Ideas can be of two kinds: mixed and realtional. The former would be like our example of the apple, which mixes a bunch of simple Ideas together into a single object. Relational would be like the complex Idea of seeing multiple apples and perceiving the relations they share with one another (spatial, but also how each appears in comparison with the others – redder, larger, smoother, etc.)
2. Primary and Secondary Qualities: Locke was a proponent of the corpuscular theory of matter, where all matter is composed of indivisible corpuscles, championed by his friend, the famos chemist Robert Boyle. While Boyle defended the division of primary and secondary qualities by appealing to his corpuscular theory, Locke took a more philosophical approach.
   • Primary Qualities: Locke says that primary qualities are “utterly inseperable from the Body [object], in what estate soever it be” and are “such as in all the alterations and changes it [the object] suffers, all the force can be used on it, it constantly keeps” and are “such as Sense constantly finds in every particle of Matter, which has bulk enough to be perceived, and the Mind finds inseperable from every particle of Matter, though less than to make it self singly be perceived by our Senses.”
     • Primary Qualities include: solidity, extension (being spatial), figure (shape), motion or rest, number, situation, bulk, texture, and motion of parts.
   • Secondary Qualities: secondary qualites are “nothing in the Objects themselves, but Powers to produce various Sensations in us by their primary Qualities, i.e. by the Bulk, FIgure, Texture, and Motion of their insensible parts.”
     • Secondary Qualities include: colors, sounds, tastes, smells, heat and cold.
3. Language: Locke understood the shortcomings of language and how it can lead to miscommunication. Much of this results from the fact that our concepts of things are not “real” universals that exist in nature, but are ways that we have classified things. In other words, only particulars exist in the world, that there is no such thing as a general object. This means that the sounds we utter, which are abstracted from the particulars (we don’t use a proper name for every insect, leaf, or chair we come in contact with), are connected with certain Ideas is conventional and not because of something inherent in the Ideas (objects) themselves. We therefore can’t assume that words have the same meaning for ourselves as they do for others. Locke doesn’t seem to have a better solution to this conundrum that all of us in a sense have our own private language than to counsel that we should be careful to accord our definitions with the common use of language.
4. Knowledge: one thing that Locke is known for is his notion that humans are a blank slate or tabula rasa. This means that we are not born furnished with knowledge, but must acquire it through experience. There are things, however, once we have the knowledge through experience, we can produce further knowledge through the combination of such experiential knowledge. For instance, one can know that the number 24 is an even number without having experienced 24 as an even number; but one has to have, through experience, learned the concepts of number and evenness.
5. Treatises on Government (using the Stanford Encyclopedia entries on Locke in general and on Locke’s political philosophy as my sources): Locke wanted to come up with what a legitimate government ought to be in order to determine what illegitimate governments are, as they would be deviations from the good government.
   • State of Nature: Locke takes a rosier view of this than Hobbes, seeing it as a state of equality. He does, however, think there are inherent problems, such as the fact that people must take enforcement of the “law of nature” into their own hands. They will likely see slights agains themselves as greater infringements than they are and therefore mete out disproportionate punishments (in other words, Locke could see that it would generate an honor culture). Furthermore, when people began needing to live in much larger communities, there were more chances for such confronations, and therefore people agreed (social contract) to abide by a civil government.
   • Private Property: for Locke, we come into private property through self-ownership. But he says that the advent of money produced conditions of inequality, which gave rise to crime. It is therefore the role of a legitimate government to protect private property.
   • Social Contract: everyone gives tacit consent to be governed by the state by virtue of the fact that they use the fruits of the state – we use the roads and infrastructure that the state has provided. This agreement cannot be revoked, since that would make civil society impossible (someone could revoke their consent, commit a murder, then reinstate their consent; if everyone decided to revoke their consent whenever the state did something people didn’t like, it would undermine the authority of the state). We are thus obligated to obey the laws set down by the state.
   • Separation of Powers: Locke actually makes the separation into the legislative, the executive, and foreign relations (what he calls federative power). The separation of the judicial branch from the legislative and executive is actually given by Montesquieu, who is discussed below. The judicial interpretation of laws, for Locke, is something inherent in both the legislative and executive branches. The roles of these three branches are as follows:
     • Legislative: to make the laws
     • Executive: to enact and enforce the laws
     • Federative: adjuticate international disputes
6. Religious Tolerance: (source: Wikipedia)
   1. earthly judges, the state in particular, and human beings generally, cannot dependably evaluate the truth-claims of competing religious standpoints;
   2. even if they could, enforcing a single ‘true religion’ would not have the desired effect, because belief cannot be compelled by violence;
   3. coercing religious uniformity would lead to more social disorder than allowing diversity.

Baruch Spinoza (November 24, 1632 C.E. – February 21, 1677 C.E.): Dutch philosopher of Portuguese Sephardic Jewish origin

1. Substance: “that which is in itself and is conceived through itself”
2. God: “a substance consisting of infinite attributes, each of which expresses eternal and infinite essence”

Nicolas Malebranche (August 6, 1638 C.E. – October 13, 1715 C.E.): French philosopher who sought to synthesize the thought of St. Augustine and Descartes, in order to demonstrate the active role of God in every aspect of the world.

Isaac Newton (January 4, 1643 C.E. – March 31, 1727 C.E.): English mathematician and physicist. His most famous work is in the independent formulation of the infinitesmal calculus (along with Leibniz, which led Newton to hate Leibniz), his universal law of gravitation, and his Opticks. Going into each of these areas is more a matter of science than philosophy. For our purposes in this post, it is most important to know what affect Newton’s work had on philosophy. This was primarily in the notion of the mechanical, clockwork universe. Philosophers who came after Newton’s discoveries were often concerned with refuting the mechanical, clockwork view of the universe, wanting to rescue notions of free will. Indeed, Kant thought of his project as deconstructing knowledge in order to rescue free will.

Gottfried Wilhelm Leibniz (July 1, 1646 C.E. – November 14, 1716 C.E.): German philosopher and mathematician. His work in mathematics, which includes independently inventing the infinitesimal calculus at the same time as Newton (which led to a venomous rivalry between the two) and binary arithmetic, were groundbreaking. He also dabbled in numerous other areas of scholarship. However, in this post I am going to focus more on his philosophical work.

1. Leibniz asserts in the Monadology §§31–32, “Our reasonings are based on two great principles, that of contradiction… [and] that of sufficient reason” (G II 612/AG 217). To these two great principles could be added four more: the Principle of the Best, the Predicate-in-Notion Principle, the Principle of the Identity of Indiscernibles, and the Principle of Continuity. (source)
2. Principle of the Best or the Best of All Possible Worlds: Leibniz makes the following argument in his Discourse on Metaphysics:
   • • God has the idea of infinitely many universes.
     • Only one of these universes can actually exist.
     • God’s choices are subject to the principle of sufficient reason, that is, God has reason to choose one thing or another.
     • God is good.
     • Therefore, the universe that God chose to exist is the best of all possible worlds
   • Humans, however, have free will, and this is why the world isn’t a perfect paradise. All God does is make actual the world that has the highest possible good.
3. Predicate-in-Notion Principle: this is the idea that the predicate is “contained within” the subject. For a proposition “S is P” the predicate P is contained within the subject S. More concretely, when we say, for instance, that “rock is hard” we are saying that the concept of hardness is contained within the concept of rock. Leibniz thought this true for what Kant would call a priori analytic (definitional) and a posteriori synthetic (empirically discovered) propositions. Kant will disagree with this.
4. Principle of Contradiction: “a proposition cannot be true and false at the same time, and that therefore A is A [law of identity] and cannot be not A [law of contradiction]” (G VI 355/AG 321) (source)
5. Principle of Sufficient Reason: everything that happens, it happens for a reason (because of some cause). Anyone with enough information will be able to answer the question of why something is the case. Or put differently in the following way (source):
   • A simple formulation of the principle is as follows:
   • (1) For every fact F, there must be a sufficient reason why F is the case.
   • The term “fact” in the above formulation is not intended to express any commitment to an ontology of facts. Still, if one wishes to avoid such connotations, the principle can be formulated more schematically:
   • (2) For every x, there is a y such that y is the sufficient reason for x (formally: ∀x∃yRyx [where “Rxy” denotes the binary relation of providing a sufficient reason]).
     • See the Analytic Philosophy section of this post for an explanation of the formal logical symbols.
6. Principle of Indiscernibles or the Principle of the Identity of Indiscernibles (PII): if two objects S₁ and S₂ share all the same predicates P₁, P₂, P₃, … P_n then those two objects are identical, i.e., S₁ = S₂. In other words, if two things share all properties, they are identical, or (∀F)(Fx ↔ Fy) → x = y.
   • Leibniz clarifies, however: “although time and place (i.e., the relations to what lies outside) do distinguish for us things which we could not easily tell apart by reference to themselves alone, things are nevertheless distinguishable in themselves. Thus, although diversity in things is accompanied by diversity of time or place, time and place do not constitute the core of identity and diversity, because they [sc. different times and places] impress different states upon the thing. To which it can be added that it is by means of things that we must distinguish one time or place from another, rather than vice versa.”
7. Principle of Continuity: changes do not occur suddenly, but must pass through intermediate stages. This is important for the idea that nothing could just begin moving immediately and on its own.
8. Complete Individual Concept: a subject contains all of its predicates eternally. Leibniz says in his Discourse on Metaphysics:
   • “…we can say that the nature of an individual substance or of a complete being is to have a notion so complete that it is sufficient to contain and to allow us to deduce from it all the predicates of the subject to which this notion is attributed.”
   • “God, seeing Alexander [the Great]’s individual notion or haecceity, sees in it at the same time the basis and reason for all the predicates which can be said truly of him.”
9. Substances: Leibniz says the following about substances in the Aristotelian sense (source):
   • (1) No two substances can resemble each other completely and be distinct. (PII)
   • (2) A substance can only begin in creation and end in annihilation.
   • (3) A substance is not divisible.
   • (4) One substance cannot be constructed from two.
   • (5) The number of substances does not naturally increase and decrease.
   • (6) Every substance is like a complete world and like a mirror of God or of the whole universe, which each expresses in its own way.
     • This is where his monadology comes from.
10. Monadology: a monad is a simple, indivisible substance. Monads make up everything, including souls and rational minds. The monads can be said to be God’s thoughts, since God has perfect knowledge of the monads and can perceive reality from the point of view of every monad. As such, the monads are continually being created at every moment “…by continual fulgurations of the Divinity.” Objects are infinitely divisible and gain their properties from the properties of the infinitesimal components. Furthermore, monads do not actually interact, but move out of a preestablished harmony.

Christian Wolff (January 24, 1679 C.E. – April 9, 1754 C.E.): German philosopher, thought to be the most important in the time between Leibniz and Kant. Leibniz and Wolff are two philosophers who are extremely influential for Kant, as a reading of Wolff’s philosophy will reveal. Important as well for writing his philosophy in German rather than Latin, making German into a language for philosophy. He was a prolific writer, so much of his philosophy will not be discussed here.

1. Rationalism: heavy focus on the a priori, the Principle of Contradiction (PC), and the Principle of Sufficient Reason (PSR).
2. Ontology: Being is something if it is possible, which is the case if all the predicates are non-contradictory. A “possible object” is one that is non-contradictory, and a “possible concept” is one that corresponds with a possible object.
   • “Nothing” is a concept that doesn’t refer to any thing and is therefore contradictory.
   • Existence is, for Wolff, a predicate that makes a possible thing actual.
   • The philosopher is then tasked with determining the sufficient reason for why something is possible.
     • “In §56 of his Ontologia, [Wolff] writes: “By sufficient reason we understand that from which it is understood why something is [or can be]”. Unlike Leibniz who essentially restricts the notion of sufficient reason to “contingent truths of fact”, Wolff considers the notion to have a much broader scope of application to include the set of all possible objects and what Leibniz calls “necessary truths of reason”. The idea that everything has a sufficient reason is presented formally by Wolff as the principle of sufficient reason.” (source)
3. Cosmology: the study of the “world-whole” in general. The world is an extended-composite of extended-composites.
   • Atoms: “unextended points of force” without internal motion but are in a constant state of change. Unlike Leibniz’s monads, the “simples” or atoms for Wolff can interact and influence one another.
   • Corpuscles: composites of Atoms, they are extended and take up space. They are still too small to be seen, but they are what determines the mechanical properties of an object.
   • Bodies: this is the level of appearances. It is a composite of composites, i.e., a composite of Corpuscles, which are composites of Atoms. The actual properties of Bodies, however, are secondary characteristics, which are mind-dependent. Wolff says that even Locke’s primary qualities, such as extension, are mind-dependent – space, according to Wolff, is just the way for the mind to organize things outside itself (this notion was very influential on Kant).
4. Psychology (Soul): Wolff innovated the notion of a separation between empirical psychology and rational psychology. The former is the observation of our mind (introspection) and the latter is reasoning about the mind.
   • Empirical Psychology: concerned with the following four things (source):
     1. the initial consideration of the human soul in an attempt to arrive at an initial definition; the consideration of the soul’s
     2. cognitive faculty and
     3. appetitive faculty; and
     4. a consideration of what can be known of the soul’s relation to the body through experience.
   • Rational Psychology: concerned with determined the independence of the soul (from the body) and the immortality of the soul
5. Natural Theology: “the science of those things that are possible through God.” It is broadly concerned with proving the existence of God and determining the nature of God (what attributes God possesses).
   • Proofs of God: Wolff uses versions of the cosmological and the ontological arguments.
   • God’s Nature: independent (not of the world), necessary (eternal and non-composite), possesses intellect (to represent all possible worlds) and will (to make a possible world actual), is perfectly free (his sufficient reason to do anything is in himself), wise (uses perfect means to actualize the world), and good.
6. Practical Philosophy: humans must strive for the perfection that exists in our essence; yet, this perfection is not dependent on God’s commands (though it is compatible with them). When we take action that brings us closer to perfection, this results in pleasure; actions that bring us further from perfection cause pain. This consequentialist aspect to Wolff’s ethics is something that Kant will reject.

Montesquieu (January 18, 1689 C.E. – February 10, 1755 C.E.): French political philosopher. Full name is Baron de Montesquieu, Charles-Louis de Secondat.

1. The Spirit of the Laws (all the follows uses the Stanford Encyclopedia entry on Montesquieu as my source): Montesquieu says that laws should conform to the nature of the peoples to whom the laws are applied: laws should be formed in accord with “the people for whom they are framed…, to the nature and principle of each government, … to the climate of each country, to the quality of its soil, to its situation and extent, to the principal occupation of the natives, whether husbandmen, huntsmen or shepherds: they should have relation to the degree of liberty which the constitution will bear; to the religion of the inhabitants, to their inclinations, riches, numbers, commerce, manners, and customs. In fine, they have relations to each other, as also to their origin, to the intent of the legislator, and to the order of things on which they are established; in all of which different lights they ought to be considered”
   1. The different kinds of governments are republican, monarchic, and despotic. Republican can be either democratic or aristocratic. The difference between monarchic and despotic is essentially the rule of law, where a monarch is bound by laws and a despot rules arbitrarily and by decree. He saw Protestantism as best for republics, Catholicism for monarchies, and Islam for despotisms.
   2. Liberty and Separation of Powers: Montesquieu essentially abided by the dictum that liberty ends only where another’s begins – a person should be allowed to do as they please so long as it doesn’t infringe on the rights of another. This liberty is, however, always under threat by the government, which is run by people who will seek to infringe on people’s liberties. The government must therefore have a system of checks and balances, which is achieved through the separation of powers. For Montesquieu, this was the separation into the legislative, executive, and judicial branches.
   3. Commerce: Montesquieu thought that commerce, rather than conquest or colonialism, was the best way for a country to enrich itself.
   4. Religion: Montesquieu was a proponent of religious tolerance and the separation of religion and state. Religion was personal, meant for the betterment of the individual, while the state was for the betterment of society. Therefore, the laws should “require from the several religions, not only that they shall not embroil the state, but that they shall not raise disturbances among themselves.”

Voltaire (November 21, 1694 C.E. – May 30, 1778 C.E.): French writer, historian, and philosopher; real name is François-Marie Arouet. He was a deist and a critic of organized religion.

1. Critique of Religion and the Church: Voltaire was a fierce critic of organized religion, particularly the Catholic Church, which he saw as a source of oppression and superstition. He famously critiqued religious intolerance and dogmatic beliefs in many of his works, including “Candide” and “Philosophical Dictionary.” He advocated for religious tolerance and the importance of personal belief grounded in reason rather than tradition.
2. Advocacy of Reason and Enlightenment Values: Voltaire was a leading figure of the Enlightenment, strongly advocating for reason, science, and empirical knowledge as the foundations for understanding the world and improving society. He believed in the power of enlightened thinking to challenge authority, dismantle superstitions, and promote progress.
3. Skepticism About Metaphysics: Voltaire was skeptical of metaphysical speculation, which he often saw as abstract and disconnected from practical life. He preferred empirical science and practical philosophy that could lead to concrete improvements in society and individual well-being.
4. Civil Liberties and Social Critique: A vocal proponent of civil liberties, Voltaire campaigned for freedom of speech, justice, and the separation of church and state. His writings often included critiques of French institutions, including the monarchy and the legal system, which he found corrupt and in need of reform.
5. Literary Style and Satire: Voltaire’s philosophy is often conveyed through his sharp wit and satirical style, making complex ideas accessible and engaging. His use of satire as a philosophical tool allowed him to critique societal norms, human follies, and institutional corruption without direct confrontation, which was both effective and dangerous in his time.
6. Political Thought: Although Voltaire was not a radical democrat, he supported enlightened absolutism or the idea of a benevolent despot who would implement reforms guided by reason and the principles of the Enlightenment. He believed that a well-educated monarch could bring about effective and rational changes necessary for societal improvement.
7. Cultural Relativism and Cosmopolitanism: Voltaire was interested in different cultures and often used his knowledge of the world to critique European customs and beliefs. His experiences and observations, including those documented during his time at Frederick the Great’s court in Prussia, informed his relatively progressive views on race and culture, advocating a form of cultural relativism unusual for his time.

George Berkeley (March 12, 1685 C.E. – January 14, 1753 C.E.): Irish philosopher

1. Idealism: Berkeley’s most famous philosophical contribution is the principle “esse est percipi” (to be is to be perceived). He argued that material objects do not exist independently of the minds that perceive them. According to Berkeley, all that exists are perceptions, which cannot exist without being perceived. Therefore, the existence of material objects depends on them being perceived by a mind.
2. Critique of Materialism: Berkeley critiqued the materialist viewpoint of his contemporaries, which held that objects exist independently of perception. He argued that materialism was inconsistent with empiricism because it posits the existence of an unknowable world beyond what can be perceived. For Berkeley, everything that exists must be immediately perceivable, and there are no abstract entities outside of perception.
3. Role of God in Perception: Berkeley addressed potential skepticism about the continuity and orderliness of perceptions (i.e., the world) by positing God as the ultimate perceiver who perceives all things at all times. God’s perception ensures that objects continue to exist even when they are not being perceived by human minds. This divine perception also accounts for the apparent objectivity and reliability of the physical world.
4. Empiricism: As an empiricist, Berkeley asserted that knowledge comes exclusively through sensory experience. This led him to deny the existence of abstract ideas, which he claimed were nonsensical constructs beyond what is immediately perceivable. He argued that we only know things through ideas and impressions that are directly experienced.
5. Critique of Abstract Ideas: Berkeley was critical of the notion of abstract ideas, which philosophers like John Locke advocated. He argued that all ideas are particular and that any concept of abstraction is merely a function of language and not a reflection of reality.
6. Ethics and Religion: Berkeley’s philosophy also had a strong religious and ethical component. He believed that understanding the world as consisting entirely of spirits and their ideas should lead to a greater appreciation for God and His order. This perspective was intended to counter atheism and skepticism, which Berkeley saw as rising threats in his time.

Francis Hutcheson (August 8, 1694 C.E. – August 8, 1746 C.E.): Scottish philosopher born in Ulster to a family of Scottish Presbyterians who became known as one of the founding fathers of the Scottish Enlightenment.

David Hume (April 26, 1711 C.E. – August 25, 1776 C.E.): Scottish philosopher. Hume saw as his project to “reject every system … however subtle or ingenious, which is not founded on fact and observation.” He is thus known as the quintessential empiricist. What follows uses the Stanford Encyclopedia entry on Hume as the main source.

1. The Mind:
   • Perceptions: all mental content. It is broken down into Impressions and Ideas.
     • Impressions: include sensations as well as desires, passions, and emotions. These are the ways that an experience feels in the moment. These can be broken down further into Original Impressions and Impressions of Reflection.
       • Original Impressions: the actual data from the five senses.
       • Impressions of Reflection: the way that such data makes us feel.
     • Ideas: “the faint images of these [impressions] in thinking and reasoning”. This is then recalling impressions in memory. These are therefore mental objects and are not the way an impression actually feels or appears.
   • Percaptions (both Impressions and Ideas) can be either simple or complex, in basically the same way that Locke formulated these notions. Impressions, according to Hume, are more “forceful” than Ideas (more vibrant or vivacious) – the memory of how something tasted isn’t as “forceful” as actually having the direct experience of tasting it. Furthermore, Ideas are only ever copies of Impressions (Hume’s so-called Copy Principle). Ideas, however, can be manipulated and conjoined with one another in our imagination, which is often done in predictable ways due to Hume’s Principle of Association, which says “There is a secret tie or union among particular ideas, which causes the mind to conjoin them more frequently, and makes the one, upon its appearance, introduce the other.”
2. Cause-and-Effect: Hume distinguished between what he called the “relations of ideas” and “matters of fact” which roughly correspond to the Kantian notion of a priori analytic and a posteriori synthetic – the former are truths that can be determined by the definitions of concepts (e.g., that the angles in a triangle add up to 180 degrees is known by virtue of the definition of a triangle) while the latter are truths that must be determined through experience (e.g., that Mount Everest is the tallest mountain in the world). Hume argues that cause-and-effect are matters of fact and not relations of ideas, since a cause is different from its effect – there is nothing in the effect that logically implies its particular cause, which means we cannot reason about causality a priori. We therefore only come up with cause-effect relationships through induction from prior experience. This is only done by “custom” and not by reason: “whenever the repetition of any particular act or operation produces a propensity to renew the same act or operation … we always say, that this propensity is the effect of Custom.”
3. Moral Philosophy: Hume was a moral sentimentalist, which essentially means that the content of our morals is derived from experience, where we have either a good or bad sentiment toward different actions we see people take. From these experiences of good and bad sentiments associated with these actions, we come to conclusions, through induction, about which actions are morally good an which actions are morally bad.
4. An Enquiry Concerning Human Understanding: here I will discuss probably Hume’s most famous work. Some of these ideas are already covered above, but here they will be discussed in the context of this work.
   1. Empiricism: At the core of Hume’s philosophy is a strict empiricism; he argues that all knowledge begins with sensory experience. Ideas are merely copies of sensory impressions—emotions and sensations—and our knowledge is limited to our direct sensory experiences and the simple ideas that arise from them.
   2. Cause and Effect: One of Hume’s most famous arguments in the “Enquiry” relates to the notion of causation. He asserts that our belief in causality, the idea that one event causes another, is not derived from reason or any logical deduction, but from habit and custom. We see that one type of event (e.g., the striking of a match) consistently follows another (e.g., the match igniting), and we come to expect this sequence. This expectation, formed from repeated experience, is what we understand as causation.
   3. Inductive Reasoning: Hume critically examines inductive reasoning, which involves making generalizations based on specific observations. He points out that while we rely heavily on induction to navigate the world, there is no rational basis for believing that the future will resemble the past, calling this the “problem of induction.” Thus, while practical, inductive reasoning does not rest on firm logical foundations according to Hume.
   4. Skepticism about the Sciences: Hume questions the claims of certainty often associated with scientific knowledge. He argues that much of what is taken as scientific knowledge is actually grounded in inductive reasoning, which, as noted, cannot be logically justified by empirical means alone.
   5. The Limits of Human Understanding: A significant portion of the “Enquiry” is dedicated to discussing the limits of philosophical speculation, particularly concerning abstract and highly theoretical topics that go beyond direct experience, such as the nature of the soul, the workings of the divine, or the origin of the universe. Hume is particularly critical of metaphysical systems that claim to exceed the boundaries of empirical observation.
   6. Religion and Miracles: In the “Enquiry,” Hume also provides a famous critique of the belief in miracles, arguing that a miracle is defined by its violation of the laws of nature. Because our knowledge of these laws is grounded in a much firmer basis of repeat observation and experience, it is always more rational to believe that a supposed miracle did not occur or that there is a natural explanation for the event.
   7. Practical Reasoning and Morality: While Hume is often perceived as a skeptic, he is not dismissive of the importance of reason in everyday life and moral decision-making. He believes that while reason alone cannot be the basis for morality, it plays a crucial role in helping us navigate the complexities of social life and moral decision-making.

Thomas Reid (May 7, 1710 C.E. – October 7, 1796 C.E.): Scottish philosopher. Often said to be David Hume’s biggest philosophical critic.

1. Common Sense Philosophy: Reid argued that common sense beliefs—such as the existence of the external world, the reliability of our perceptions, and the existence of other minds—are inherent and form the basis of human knowledge. He believed these foundational beliefs do not require further justification through sensory experience or reasoning, contrasting sharply with the empirical skepticism of his contemporaries.
2. Critique of the Theory of Ideas: Reid criticized the philosophical tradition from Descartes to Hume that all human knowledge is mediated through ideas, which are mental representations that serve as the only objects immediately available to the mind. He argued this led inevitably to skepticism about the external world and about the self, as it disconnects our direct experience from the world and other persons. Instead, Reid posited that perceptions are directly of the external world, not of ideas in our minds.
3. Direct Realism: As a proponent of direct realism, Reid contended that senses provide us with immediate knowledge of the external world, without the need for any intervening mental representation. This approach intended to reassure the common intuitive sense of reality that is experienced by ordinary people, asserting that our perceptions and sensory experiences are inherently trustworthy.
4. Theory of Perception: Reid developed a detailed account of perception that differentiated between sensation and perception. He argued that sensations are raw data provided by the senses, which are then actively processed by the mind to form perceptions, which include an awareness of the object being perceived. This process, according to Reid, is instinctual and involves innate knowledge built into the human mind.
5. Moral Philosophy: Reid also contributed significantly to ethics, arguing that moral knowledge is based on principles of common sense, similar to other types of knowledge. He believed that humans have a natural faculty for moral judgment, which includes innate principles of right and wrong. This faculty enables individuals to make moral judgments that are immediate and self-evident.
6. Philosophy of Action and Agency: Reid was also interested in the philosophy of action, particularly in the concept of human freedom and agency. He argued for an agent-causal account of free will, wherein actions are caused by agents (people), and not by thoughts, desires, or physical processes alone. This view supports the notion of moral responsibility.

Jean-Jacques Rousseau (June 28, 1712 C.E. – July 2, 1778 C.E.): Genevan philosopher

1. Natural Man and Civil Society: Rousseau contrasts the “natural man” living in a state of nature with man living in civil society. He theorizes that humans in their primeval state were solitary, simple, and peaceful; their desires were few, and their needs were easily satisfied by nature. The transition to civil society, while providing benefits like security and property, introduced inequality, competition, and moral corruption.
2. The Social Contract: In his “The Social Contract” Rousseau outlines his political philosophy concerning the legitimate source of political authority. He introduces the famous idea that “Man is born free, and everywhere he is in chains,” suggesting that governments exist to protect the people, who are sovereign. The “general will,” as Rousseau defines it, is not the will of the majority, but the collective will directed towards the common good. Rousseau argues for a form of direct democracy where citizens directly make legislative decisions.
3. General Will: Central to Rousseau’s idea of political legitimacy is the concept of the general will, which represents the true, collective will of the people aimed at the common good. According to Rousseau, the general will is always right and tends to the public advantage. However, it may not always align with the individual wills of the populace, who may be influenced by private interests.
4. Education and Development: Rousseau’s “Emile, or On Education” is a foundational text in the philosophy of education. Rousseau presents an educational journey designed to foster a child’s natural instincts and abilities, arguing that education should develop naturally according to the inherent stages of human life. He emphasizes learning through experience rather than through formal academic instruction.
5. Critique of Reason and Arts: In his “Discourse on the Sciences and Arts,” Rousseau argues that the progression of the sciences and arts has caused the corruption of virtue and morality. He suggests that the pursuit of knowledge and refinement of taste do not improve human life but rather lead to vice and dependency.
6. Influence on Romanticism: Rousseau’s emphasis on emotion and his valorization of the “noble savage” greatly influenced the Romantic movement. His belief in the goodness of human nature when free from the corrupting influence of society resonated with Romantic poets and philosophers.

Denis Diderot (October 5, 1713 C.E. – July 31, 1784 C.E.): French philosopher

1. Co-founder of Encyclopedia, or a Systematic Dictionary of the Sciences, Arts, and Crafts with Jean-Baptiste le Rond d’Alembert. Usually just known as the Encyclopédie, it was a watershed achievement during the Enlightenment. It was meant to be a repository of knowledge (sort of like what Wikipedia is now) so that anyone could have access to information.
2. He is known for his religious skepticism. Indeed, the Encyclopédie was banned by both the Catholic church and the French government. Many see the Encyclopédie as an inspiration for the French revolution.

Alexander Gottlieb Baumgarten (July 17, 1714 C.E. – May, 1762 C.E.): German philosopher and brother of Siegmund Jakob Baumgarten. Known most for his pioneering work in aesthetics, and is even credited with changing the meaning of the word aesthetics to being the study of good and bad art.

Siegmund Jakob Baumgarten (March 14, 1706 C.E. – July 4, 1757 C.E.): German theologian and brother of Alexander Gottlieb Baumgarten.

Adam Smith (June, 1723 C.E. – July 17, 1790 C.E.): Scottish economist

1. Invisible hand of the market.

Edmund Burke (January 12, 1729 C.E. – July 9, 1797): Irish-British statesman and philosopher

1. Realist and pragmatist in politics.

Moses Mendelssohn (September 6, 1729 C.E. – January 4, 1786 C.E.): Jewish German philosopher.

1. Thinks that mathematics and metaphysics are closely related. The differences are the following (source):
   1. first, metaphysics’ greater reliance upon arbitrary signs (signs that do not essentially coincide with what is signified);
   2. second, the holistic content of metaphysics (no quality can be defined without an adequate insight into the others); and
   3. third, metaphysics’ need to establish the actual existence of what corresponds to the analyzed concepts
2. Idealism, Materialism, Dualism: Mendelssohn thought that the disagreements between these schools of thought were mostly linguistic (i.e., because of the reliance upon arbitrary signs). He appeared to lean more toward idealism, and thought that God needed to be proven to exist in order to have certainty of an external world. Mendelssohn does this with a cosmological argument (appealing to the principle of sufficient reason) an a version of the ontological argument.
   • Mendelssohn’s ontological argument (adapted from here): Non-existent things are either impossible or possible. If it’s impossible, then it must be contradictory. If it is possible, then its intrinsic properties are insufficient to determine its existence, and so depends on something external. If God doesn’t exist, then it’s either because the idea of God is impossible or because it’s possible (contingent) but not actual. Since contingency means it is dependent and being independent is greater than dependence, it contradicts the essence of a perfect being for that being to be contingent. Thus, the idea of a perfect being can’t be the idea of something merely possible. But the idea of a perfect being also doesn’t contain determinations that must be affirmed and denied at the same time. In other words, the idea is not impossible. And so Mendelssohn concludes that God exists from the consideration that the idea of God cannot be the idea of something nonexistent.
3. Rational Psychology: Mendelssohn gives an account of the simplicity (not composite, since its character is unifying) and immortality of the human soul.
   • “We would be able neither to remember nor to reflect nor to compare nor to think, indeed, we would not even be the person who we were a moment ago, if our concepts were divided among many and were not to be encountered somewhere together, combined in the most precise ways they can. We must, therefore, assume at least one substance that combines all concepts of the component parts…. There is, therefore, in our body at least one sole substance that is not extended, not composed, but instead is simple, has a power of presentation, and unites all our concepts, desires, and inclinations in itself” (Phädon (2007), pp. 119f (translation slightly altered)/Gesammelte Schriften, 3/1, pp. 96f). (source)
4. Ethics: there are major premises that are general maxims (that can be proven with mathematical rigor) for how to act, and then minor premises that are the particular situation one is faced with. Thus, ethics is a kind of syllogism that looks like the following:
   • 1. If presented with situation A, then do B
     2. Situation A is presented
     3. Therefore, do B
   • Imperfect applications of this syllogism is what causes people to have differing views on what is good and bad. Once a person has sufficient insight into the general maxims, they would know how to be perfectly moral.
   • The maxims that Mendelssohn comes up with are the following (source): “Summing up these three proofs, Mendelssohn lists three basic maxims that lead to the same conclusion. Whether we (1) consider what is common to all human inclinations, (2) recognize ourselves as entities endowed with free wills, or (3) acknowledge that we are God’s creation, “all three maxims lead to the common conclusion: perfect yourself and others.””

Friedrich Heinrich Jacobi (January 25, 1743 C.E. – March 10, 1819 C.E.):

Johann Gottfried Herder (August 25, 1744 C.E. – December 18, 1803 C.E.)

Immanuel Kant (April 22, 1724 C.E. – February 12, 1804 C.E.): German philosopher

1. Intuition: the way that objects appear to us. You can maybe think about it like the stage on which our representations of the world are experienced.
2. Understanding: the application of concepts to the objects in our intuition.
3. Transcendental Deduction: taking the way things are as a given and then attempting to deduce what conditions must hold in order for the way things are to be possible.
4. Transcendental Aesthetic: this is the part of Kant’s Critique of Pure Reason where he discusses the form of our intuition. He says that our intuitions always occur in space and in time. Indeed, it’s impossible to have an intuition that is not spacial and temporal. Everything we experience is extended in space and occurs as a series in time.
5. Transcendental Analytic: this is the part of Kant’s Critique of Pure Reason where he lays out the general concepts for the possibility of experience. These concepts, called the categories of understanding, take the form of judgements, which are the forms of propositions in an Aristotelian sense.
6. Phenomena and Noumena: the former is the world as it is experienced by people where the latter is the world of things in-themselves. In the realm of experience, the Phenomena, the sorts of things that we understand, like cause-and-effect, hold true. For things in-themselves, the Noumena, we cannot know whether this is the case or not.
7. Transcendental Dialectic: this is the part of Kant’s Critique of Pure Reason where he shows that, in light of his discussion in the Transcendental Aesthetic and the Transcendental Analytic, reason itself is constrained. Past philosophers have attempted to go beyond what our faculty of reason is capable of to describe things in-themselves.
8. Categorical Imperative

You can learn more about Immanuel Kant from my video series covering his work:

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(Post)-Kantian and German Idealist (1750 C.E. – 1850 C.E.)

Salomon Maimon (1753 C.E. – November 22, 1800 C.E.): Lithuanian Jewish philosopher. Maimon’s work significantly influenced the development of German Idealism. His critiques of Kant and his attempts to reformulate critical philosophy laid the groundwork for the later developments by Fichte, Schelling, and Hegel, each of whom sought in their own ways to address some of the gaps and issues Maimon had pointed out in Kantian philosophy.

1. Critique of Kant’s Transcendental Idealism: Maimon is perhaps best known for his critique of Immanuel Kant’s transcendental idealism. While he was largely in agreement with the critical approach of Kant, Maimon argued that Kant’s categories of understanding do not sufficiently account for how they apply to the particulars in our experience. He contended that Kant’s philosophy left a gap between the a priori forms and categories of understanding and the empirical content these forms are supposed to structure.
2. Theory of Knowledge: Maimon developed what he called a “transcendental philosophy” which sought to demonstrate that all a priori knowledge (knowledge independent of experience) must relate to the infinite intellect. He introduced the notion of an “infinite mind” as a way to bridge the gap between Kantian categories and the particulars of sensory experience, suggesting that such categories actually presuppose an infinite intellectual capacity, unlike the finite human intellect.
3. Skepticism and the Principle of Determinability: Another significant aspect of Maimon’s philosophy is his principle of determinability, which states that for something to be determined as an individual object, it must be distinguishable from all other objects (this is also sometimes referred to as his principle of difference). His approach leads to a form of skepticism, as he believed that complete knowledge (or complete determination of objects) is unachievable for the finite human mind.
4. Philosophical Idealism and Monism: Maimon advocated a form of idealism that was more radical than Kant’s, proposing a kind of philosophical monism. According to Maimon, everything including our experience and the objects of experience can be seen as modifications of the mind or intellect. This perspective leads towards a more subjective idealism, suggesting that all reality is fundamentally mental.

Karl Leonhard Reinhold (October 26, 1757 C.E. – April 10, 1823 C.E.): Austrian-German philosopher

1. He was a big fan of Kant’s work, but thought that Kant left his work incomplete. And so, like many of the “post-Kantian” philosophers, he set out to fix and complete Kant’s critical philosophy. To do this he began his project of what came to be called (by himself) “Elementary Philosophy”.
2. Elementary Philosophy: what is philosophy and how is it possible? It is to establish “universally valid” propositions that are understandable and agreed upon by everyone. Furthermore, these propositions must be systematic (consistent and complete), able to logically connect to one another. He therefore saw it as one of his tasks to systematize Kant’s philosophy.
3. To systematize, Reinhold thought that philosophy needed to be foundationalist – able to be derived from first principles, i.e., all propositions can be derived from the basic axioms in a mathematical way (although Reinhold’s conception of derivation is somewhat unclear). He therefore sought to discover the (self-evident) first principle (hence why his philosophy is elementary).
4. From the Stanford Encyclopedia of Philosophy: “What then is the “first principle” of the Elementary Philosophy? It is the “Principle of Consciousness,” namely, the proposition that “in consciousness, the subject distinguishes the representation from the subject and the object and relates the representation to both” (Beyträge I, p. 167). In this proposition, the term “representation” [Vorstellung] designates whatever we are directly conscious of whenever we are conscious of anything whatsoever; the term “subject” designates the one who “is conscious” of whatever one is conscious of (the “conscious subject” or “subject of consciousness”); and the term “object” designates that “of which” the representation is a representation (the intentional object of consciousness, that to which the representation “refers”).”
5. From this Reinhold goes on to show “that space, time, the twelve categories, and the three forms of the ideas are originally nothing but properties of mere representations” (Fundament, pp. 72–73)
6. Both Fichte and Schelling were greatly influenced by Reinhold’s Elementary Philosophy

Johann Gottlieb Fichte (May 19, 1762 C.E. – January 29, 1814 C.E.): German philosopher. Can perhaps be thought of as the bridge between the so-called “post-Kantians” and the German idealists (Schelling was a student of Fichte’s)

1. Wissenschaftslehre (Theory of Scientific Knowledge): Fichte, having read both Kant and Reinhold, thinks he knows what is even more fundamental than Reinhold’s Principle of Consciousness. He saw that there were two competing and mutually exclusive (both cannot be true and neither can refute the other) possible starting points:
   1. 1. Selfhood (Free Will): leads to idealism
      2. Thinghood (Necessity): leads to dogmatism (Cartesian style rationalism)
   2. Fichte thought the former stronger than the latter, since it allows an explanation of the experience of objects, whereas the latter cannot be used to deduce the possibility of experience. One’s own free will, however, has to be taken as a brute fact, according to Fichte – it has to be presupposed, since it cannot be proven philosophically.
   3. The first principle then, according to Fichte, is “the I posits itself as self-positing.”
      • • “To posit” (setzen) means “to be aware of,” “to reflect upon,” or “to be conscious of”; it does not mean “to create” (source)
        • “In Fichte’s technical terminology, the original unity of self-consciousness is to be understood as both an action and as the product of the same: as a Tathandlung or “fact/act,” a unity that is presupposed by and contained within every fact and every act of empirical consciousness, though it never appears as such therein.” (source)
        • From this first principle, Fichte says a transcendental deduction of what conditions must hold in order for the “self-positing I” to be possible must be completed.
      • Anstoß: the “I” posits itself as unlimited and absolute, but discovers that it is in fact limited (it cannot determine, for instance, why sensations have the sensation that they do; this is not something the “I” has control over). This limitation, however, is posited by the “I” which therefore divides the “I” against itself. This tension leads to our conscious experience. The Anstoß is thus a condition of the possibility of experience.
2. System of Ethics: (source) – divided into three sections
   • 1. “The deduction of the principle of morality” gives the transcendental reconstruction of the moral law and freedom as a necessary condition for the thinking ‘I.’
     2. “The deduction of the reality and applicability of the principle of morality” explains how the concept derived in in the first part can have an effect in the world.
     3. “The systematic application of the principle of morality, or ethics in the narrower sense,” presents a system of duties derived from the first and second parts.
   • Tries to make connection between Kant’s moral law and Kant’s theory of subjectivity, and between theoretical and practical reason. Fichte claims that the moral law is the condition for being a self-conscious entity, saying that thinking is practical insofar as it must construct itself as a thinking being under the moral law. We therefore have to think of ourselves as necessarily under the moral law.
3. Foundations of Natural Right
   • Relation of Right: recognition of others as conscious, rational beings
   • Sphere of Freedom: people must be free from outside forces
   • Original Right: a person must be considered as a cause and not an effect. This means that to treat someone as an effect is to use coercion against them, which is immoral.

August Wilhelm Schlegel (September 8, 1767 C.E. – May 12, 1845 C.E.): German Indologist, poet, translator and critic, and with his brother Friedrich Schlegel the leading influence within Jena Romanticism.

Karl Wilhelm Friedrich Schlegel (March 10, 1772 C.E. – January 12, 1829 C.E.): German poet, literary critic, philosopher, philologist, and Indologist. With his older brother, August Wilhelm Schlegel, he was one of the main figures of Jena Romanticism.

Jakob Friedrich Fries (August 23, 1773 C.E. – August 10, 1843 C.E.): German philosopher and mathematician

1. In his 1807 work The New or Anthropological Critique of Reason, he wanted to find out how Kant’s critical method and transcendental deduction provides knowledge. To do this, he Fries was prepared to use empirical psychology methods.
   1. “Fries said the critical method provides knowledge by a regressive analysis which begins with the empirical facts of consciousness; thus, the, critical method leads to empirical, not metaphysical, knowledge. … Fries maintained that we come to know the a priori forms in our thought only as a matter of experience.” (source)
   2. “The basis of Fries’s critical method – its first step – was self-observation. Through a careful phenomenology of the mind Fries hoped not only to determine the various types of knowledge, but also to describe and classify the general types of mental processes which constitute mental life. He viewed the establishment of an adequate theory of the mind as a necessary preliminary to a critical analysis of the innate forms of the mind.” (source)

Gottlob Ernst Schulze (August 23, 1761 C.E. – January 14, 1833 C.E.): German philosopher

Friedrich Wilhelm Joseph Schelling (January 27, 1775 C.E. – August 20, 1854 C.E.): German philosopher. Schelling’s thought evolved considerably over his lifetime, moving from an early focus on nature and identity to later explorations of mythology and revelation. Schelling’s exploration of the unconscious and his ideas about the sources of creativity and personal identity anticipated some themes that would later be central in existentialism and psychology. His emphasis on the irrational and unconscious processes influenced thinkers such as Søren Kierkegaard and Friedrich Nietzsche, as well as the development of psychoanalysis.

1. Nature Philosophy (Naturphilosophie): In his early works, Schelling proposed that nature itself has a dynamic, self-organizing process that reflects the absolute, or the underlying reality of existence. His “Naturphilosophie” sought to bridge the gap between nature and spirit by suggesting that the natural world is a visible manifestation of the underlying spiritual reality. This idea that nature and mind are different expressions of the same underlying reality was radical, positing a sort of pantheism where God is immanent in nature.
2. Identity Philosophy: Schelling’s middle period is marked by his Identity Philosophy, where he argued for an absolute identity of the real and the ideal, of nature and spirit. His system posited that the absolute is an indeterminate unity that precedes the distinction between subject and object. This phase of his philosophy aimed to show how the world of appearances (nature) and the realm of concepts (spirit) could be seen as arising from the same foundational reality.
3. Freedom and Evil: Schelling’s later philosophy focused on issues of human freedom and the origin of evil. In his “Philosophical Investigations into the Essence of Human Freedom” (1809), Schelling contended that freedom is the central characteristic of human existence, and that evil arises naturally from the misuse of this freedom. He introduced a notion of a ground or unground that precedes God, which represents the dark, irrational forces in nature and human beings. This idea suggested a dynamic tension within the absolute itself, between its dark, chaotic nature and its rational, orderly manifestation.
4. Positive Philosophy: In his final phase, Schelling developed what he called “Positive Philosophy,” which aimed to complement his earlier “Negative Philosophy” (focused on abstract principles). Positive Philosophy dealt with the concrete and historical manifestations of the absolute, particularly through art, mythology, and revealed religion. He argued that these manifestations provide a more direct access to understanding the absolute than abstract philosophical reasoning.

Georg Wilhelm Friedrich Hegel (August 27, 1770 C.E. – November 14, 1831 C.E.): German philosopher

1. Dialectical Method: Hegel is probably most famous for his dialectical method. This is a process of development that encompasses thesis, antithesis, and synthesis. In this process, a given state of affairs (thesis) generates its opposite (antithesis), and the tension between these leads to a new state (synthesis), which transcends and reconciles the contradiction. This dialectical method is applied across his system to explain the development of consciousness, history, and logic.
2. Phenomenology of Spirit: Hegel describes the development of “Geist” (spirit or mind) from its most immediate and subjective state to absolute knowing. This journey of consciousness, or spirit, involves various stages of awareness, including self-consciousness, reason, and the spirit. Each stage represents both an epistemological standpoint and a moment in the historical development of human freedom.
3. Absolute Idealism: Hegel’s philosophy is characterized by absolute idealism, where reality is seen as being fundamentally rational and mental. According to Hegel, the real is rational; that is, reality is a manifestation of reason itself. This leads to his view that the world is essentially a reflection of the mind (Geist), which evolves towards full self-awareness and freedom.
4. Philosophy of History: Hegel proposed a philosophy of history based on the idea that history is a rational process. History, for Hegel, is the unfolding of freedom through the development of human consciousness and societies. He famously argued that history has a teleological structure—it moves purposefully towards the realization of human freedom.
5. Science of Logic: In his “Science of Logic,” Hegel explores the structures of thought itself, independent of the particular forms of its historical or cultural manifestation. He examines categories of thought and their development, which are seen as mirroring the logical structure of the world. This work forms the core of his system, underpinning his approach to nature and spirit.
6. Political Philosophy: In his “Philosophy of Right,” Hegel develops a view of modern societies and states as embodiments of rational principles. The state, according to Hegel, is the realization of ethical life (Sittlichkeit) in which the freedom of individuals is actualized through their participation in social institutions such as family, civil society, and government.

Johann Adam Möhler (May 6, 1796 C.E. – April 12, 1838 C.E.): German Roman Catholic theologian and priest associated with the Catholic Tübingen school. He significantly contributed to the development of Catholic theology in the 19th century, especially during the period of German Romanticism. His thought is often seen as a response to the challenges posed by Protestant theology, Enlightenment rationalism, and the burgeoning historical-critical method of scriptural interpretation. Möhler’s integration of Romantic ideals with Catholic theology provided a robust counter-narrative to both the Enlightenment’s emphasis on reason and Protestantism’s focus on scripture alone.

1. Unity and Community: Central to Möhler’s theology is the concept of the unity and organic nature of the Church. Influenced by the Romantic movement’s emphasis on organic wholes, history, and community, Möhler portrayed the Church not as a mere institution but as a living organism, a spiritual community that transcends time and space. This idea was particularly expressed in his seminal work, “Symbolik” (1832), where he examined the creeds and doctrines of the Catholic Church in contrast to Protestantism, emphasizing the Catholic Church’s continuity, unity, and universality.
2. Symbolism and Sacramental Theology: Möhler’s approach to religious doctrine and symbols was deeply influenced by Romanticism’s broader valuation of art, symbolism, and aesthetics. He argued that religious truths are expressed symbolically through the Church’s sacraments and liturgy, which convey divine realities in tangible forms. For Möhler, these symbols were not arbitrary but deeply rooted in the Church’s living tradition and communal worship.
3. Development of Doctrine: Möhler was a precursor to what would later be known as the development of doctrine, an idea that doctrines could develop over time while remaining faithful to the essence of the Christian faith. This perspective was in keeping with the Romantic view of historical processes as organic developments rather than merely mechanical or linear progressions.
4. Response to Protestantism: Möhler’s work was often framed as a response to the Protestant Reformation’s principles, particularly the emphasis on individual interpretation of the Scriptures. He critiqued the fragmentation and subjectivism he perceived in Protestant ecclesiology and argued for the authority of the Catholic Church as a necessary mediator and interpreter of Christian truth.
5. Ecclesiology: His ecclesiology emphasized the mystical body of Christ as realized in the Church, where all members are interconnected. This vision was set against the backdrop of the emerging nationalism and individualism of his time, proposing a model of Christian unity that transcended ethnic and national boundaries.

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Middle Modern (1800 C.E. – 1920ish C.E.)

Jeremy Bentham (February 15, 1748 C.E. – June 6, 1832 C.E.): English philosopher, jurist, and social reformer regarded as the founder of modern utilitarianism. Bentham defined as the “fundamental axiom” of his philosophy the principle that “it is the greatest happiness of the greatest number that is the measure of right and wrong.”

1. Principle of Utility: Bentham’s philosophy is centered around the principle of utility, which he defined as the maximization of pleasure and minimization of pain. He famously stated, “it is the greatest happiness of the greatest number that is the measure of right and wrong.” This principle serves as the basis for decision-making in both personal ethics and public policy, advocating for actions that produce the greatest benefit for the greatest number of people.
2. Hedonistic Calculus: To apply the principle of utility, Bentham proposed a method known as the “hedonistic” or “felicific” calculus. This method involves measuring the pleasure and pain resulting from any action based on several criteria, including intensity, duration, certainty, and propinquity. This calculation aims to quantify the moral value of actions based on their consequences.
3. Reform of Law and Society: Bentham’s utilitarian philosophy extended into his views on law and social reform. He argued for laws to be clearly defined and designed to promote the general happiness of the society. He was a strong advocate for legal and prison reforms, education reforms, and animal rights. His work influenced significant changes in these areas, particularly in the English legal system.
4. Critique of Natural Rights: Bentham was critical of the concept of natural rights, famously dismissing them as “nonsense upon stilts.” He argued that the idea of rights being inherent and independent of societal or governmental acknowledgment was flawed. Instead, he believed rights should be conferred based on their utility in promoting the general happiness.

David Ricardo (April 18, 1772 C.E. – September 11, 1823 C.E.): British political economist

Auguste Comte (January 19, 1798 C.E. – September 5, 1857 C.E.): French philosopher and writer who formulated the doctrine of positivism. He is often regarded as the first philosopher of science in the modern sense of the term.

Harriet Martineau (June 12, 1802 C.E. – June 27, 1876 C.E.): English social theorist often seen as the first female sociologist.

Charles Darwin (February 12, 1809 C.E. – April 19, 1882 C.E.): British scientist who formulated the theory of evolution by natural selection. Click the links below for my explications of Darwin’s theory.

1. Natural Selection
2. Evidence
3. Higher Concepts

John Stuart Mill (May 20, 1806 C.E. – May 8, 1873 C.E.): English philosopher, political economist, Member of Parliament and civil servant. One of the most influential thinkers in the history of classical liberalism, he contributed widely to social theory, political theory, and political economy.

1. Utilitarianism: Mill is best known for his work in utilitarian ethics, as articulated in his book “Utilitarianism.” He expanded on Bentham’s idea that the right actions are those that maximize pleasure and minimize pain, proposing a more sophisticated version of the happiness principle. Mill introduced a distinction between higher and lower pleasures, arguing that intellectual and moral pleasures (higher pleasures) are superior to more base forms of happiness (lower pleasures). According to Mill, the worth of different pleasures can be quantitatively assessed by those who have experienced both.
2. Liberty and Individuality: In his work, “On Liberty” Mill expounded on the concept of personal freedom and its importance in a democratic society. He argued for the “harm principle”: individuals should be free to do anything they want as long as they do not harm others. This work emphasizes the importance of individuality and freedom of expression, arguing that they are essential for personal and societal progress.
3. Social and Political Philosophy: Mill’s contributions to social and political philosophy include his support for representative democracy and his belief in the need for social reforms. He was an early advocate for women’s rights and gender equality, as detailed in his essay “The Subjection of Women.” Mill believed in the necessity of social and political institutions that could promote personal development and prevent the tyranny of the majority.
4. Empiricism and Scientific Method: Influenced by the empirical methods of science, Mill held that knowledge is derived from sensory experience. In his “System of Logic” he developed a framework for the scientific investigation of nature and society, which he believed could be used to improve human understanding and the condition of society through reforms.
5. Economic Philosophy: Mill’s ideas on political economy are outlined in his work “Principles of Political Economy.” He argued for a utilitarian foundation in economic decisions but recognized the limitations of laissez-faire capitalism. He advocated for worker cooperatives and supported some socialist ideas, emphasizing the need for a fair distribution of resources.
6. Ethical and Religious Thoughts: While a utilitarian, Mill was also deeply concerned with moral and ethical development, which he believed was crucial for the proper functioning of society. Although skeptical of organized religion, he saw the importance of religious sentiment for moral life and social cohesion.

Ludwig Feuerbach (July 28, 1804 C.E. – September 13, 1872 C.E.): German anthropologist and philosopher who was very critical of Christianity.

Karl Marx (May 5, 1818 C.E. – March 14, 1883 C.E.): frequently worked with Friedrich Engels, making their philosophies difficult to disentangle from one another. Many things that are considered Marxist, such as the stages of dialectical materialism, were never written about by Marx personally, but are claimed by Engels (who outlived Marx) to have been part of Marx’s thought.

1. Means of Production: the machines and natural resources needed to produce finished commodities.
2. Use Value vs. Exchange Value: the former is the value that something has because of its function while the latter is the value that it has on the market. The exchange value is how we can say that x amount of A [which I’ll represent as A(x)] and y amount of B [which I’ll represent as B(y)] have equal value (perhaps x amount of copper and y amount of cabbage). We can thus say that A(x) = B(y). But, since, for instance, cabbage is perishable, there must be a way of making an exchange at different points in time, which is where money comes in; we can then say that A(x) = $ = B(y). That allows the cabbage farmer to sell the cabbage for money before they perish and then use that money at a different time to purchase the copper.
   • Marx named the difference between the two (Use Value and Exchange Value) a contradiction, since the Use Value is qualitative while the Exchange Value is quantitative. Because of this contradiction, since capitalists produce commodities only for their Exchange Value and not their Use Value, the capitalists will produce commodities that have only the bare minimum use value in order to maximize profits (by producing more at a larger scale), leaving us with suboptimal commodities.
   • Contradiction: Marx often uses the word contradiction when writing about capitalism, saying that there are inherent contradictions, such as between Use Value and Exchange Value. This is often misconstrued as the kind of contradiction talked about in formal logic (where A and not-A cannot both be the case at the same time). This is misleading, however, since the contradiction is actually meant more like an inconsistency.
   • Labor Theory of Value: the value of something comes from the difficulty of attaining or producing that thing.
3. Surplus Value: the difference between the value of the commodity as a function of the labor needed to produce the commodity and the amount the laborer is paid. This difference becomes profit for the capitalist, who did zero work to produce the commodity, and therefore profits off the surplus value that the commodity possesses.
4. Wage Labor: the notion that workers must work for subsistence – a worker gets paid, then has to spend that money on essentials to live, which then means they must continue working in order to get paid again, maintaining a vicious cycle.
5. Crises: the ability to exchange commodities at different points in time untethers those commodities from each other. For instance, a person sells so many cabbages for a certain amount of money and then a week later uses that money to buy copper, the net exchange is cabbage for copper, but these events are separated in time. During that time, many things could have happened, including the devaluing of currency, inflation, theft, and so on. Money also makes it possible for people to take loans and credit, wherein interest rates can change or an inability to pay back loans for a variety of reasons can lead to default.
   • For Marx, a crisis happens when too many commodities are produced than can be sold (since the capitalist will always be expanding (infinite growth) in order to gain a competitive edge and maximize profits), but nobody will be willing to lower the prices since the first firm to do so might jump the gun and lose money. This will force firms to default on loans and go out of business. This results in job loss for the workers, who will then be left destitute and desperate.
   • Marx predicted that such crises will grow worse and worse in the future, leading to a revolt by the workers that will usher in a dictatorship of the proletariat.
6. Commodity Fetishism: production and exchange is a relationship among things rather than people.
7. Alienation: the worker produces commodities that do not benefit themselves in any way, alienating them from the fruits of their labor. Likewise, the division of labor, and competition for employment, has alienated the workers from each other.
8. Ideology: those ideas that are used by the bourgeois to justify the current social relations. They are meant to make people think that the way things are (with a small number of capitalists and a majority of workers doing wage labor) is normal, natural, and necessary.
9. Dictatorship of the Proletariat: the workers seize the means of production and take control of the state. This is often conflated with Leninist/Maoist notions that there is a dictator who has to pull their (usually agrarian/feudal) society into the communist future. But for Marx it is actually more literal in that, under socialism (the next step after capitalism) the society is run by the proletariat. Marx predicts that after a while, this dictatorship will become obsolete and the proletariat will dissolve the state away and bring society into a stateless, classless communism.
10. Dask Kapital (aka Capital: Critique of Political Economy): here I will go more in depth on Marx’s most famous work. Some of these ideas are already discussed above, but here they will be put in context of this work.
    1. Volume I – The Process of Production of Capital: This volume focuses on the capitalist mode of production. Marx analyzes commodities, the labor process, and the production of surplus value. He introduces the concept of commodity fetishism, the way in which the social relationships between producers are obscured by their relationships with the products they create. A significant part of the volume is devoted to the theory of surplus value, which Marx argues is the source of profit for capitalists and is derived from exploiting laborers, who are paid less than the value they produce.
    2. Labor Theory of Value: Marx explains that the value of any commodity is determined by the amount of socially necessary labor time required to produce it. This theory is used to describe how capitalists, who own the means of production, extract surplus value from workers, who only own their labor. This exploitation is the fundamental contradiction and conflict in capitalism, according to Marx.
    3. Volume II – The Process of Circulation of Capital: Edited by Engels and published in 1885, this volume deals with the processes involved in the circulation and turnover of capital. It examines how capital flows back into production to generate further growth, addressing the cycles that involve the reproduction and accumulation of capital. Marx discusses the distinctions between fixed and variable capital, and the reproduction schemes that describe the movement of capital and commodities across different sectors of the economy.
    4. Volume III – The Process of Capitalist Production as a Whole: Also edited and published by Engels, in 1894, this volume introduces the concepts of the rate of profit, commercial profit, interest, and rent. It explores the distribution of surplus value created in production into different forms of capitalist income. Marx delves into the law of the tendency of the rate of profit to fall, a key dynamic in capitalist economies that he argues leads to crises and the eventual decline of capitalism.
    5. Capitalist Dynamics and Crisis: Throughout the three volumes, Marx discusses the internal contradictions within the capitalist system, such as the concentration and centralization of capital, booms and busts, and the inherent instability and tendency toward crisis. These contradictions, he argues, drive ongoing class struggle and will ultimately lead to the overthrow of the capitalist system and the establishment of socialism.

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20th Century Until Now

For this part, which covers roughly the twentieth century until now, I am going to break it down by the various schools of thought. This is also going to have many, many more people who are left out, since the number of notable philosophers has exploded, and so I will focus mainly on those names big enough that even people outside of philosophy may have heard of them.

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Critical Theory

W. E. B. du Bois (February 23, 1868 C.E. – August 27, 1963 C.E.): William Edward Burghardt Du Bois was involved in the creation of the NAACP (National Association for the Advancement of Colored People). He is highly regarded as a black scholar who worked during the Jim Crow era and was instrumental in the scholarly work of the black experience in the United States.

1. The Souls of Black Folk: Du Bois’s most famous work, where he developed the idea of the double consciousness
2. Double Consciousness: the way black Americans experience living in the world. Is is living with the consciousness of a black person and as a person living in world created by (and for) white people. It’s a double consciousness of how black people view themselves and of how the world views them.
   • “One ever feels his twoness,—an American, a Negro; two souls, two thoughts, two unreconciled strivings; two warring ideals in one dark body, whose dogged strength alone keeps it from being torn asunder. The History of the American Negro is the history of this strive-this longing to attain self-conscious manhood, to merge his double self into a better and truer self. He simply wishes to make it possible for a man to be both a Negro and an American, without being cursed and spit upon by his fellows, without having the doors of Opportunity closed roughly in his face.”
3. Race and Racism: Du Bois was a pioneer in discussing the construction and socio-political implications of race. He argued that race is a social construct used to perpetuate inequality. Unlike many of his contemporaries, who saw the accommodation to segregation as a viable strategy, Du Bois advocated for the assertion of civil rights and socio-economic opportunities for African Americans.
4. Talented Tenth: Du Bois believed that a “Talented Tenth” of the African American population, through rigorous higher education and leadership development, could become leaders of the race and help lift the entire black population. This notion stemmed from his belief in the power of exceptional individuals to effect significant social change, though his views on this strategy evolved over time.
5. Pan-Africanism: Later in his career, Du Bois became increasingly involved in the Pan-African movement, which sought to unite people of African descent worldwide. He organized several Pan-African Congresses that aimed to address the issues facing Africa due to European colonialism and the diaspora due to the slave trade.
6. Critique of Capitalism and Shift Towards Socialism: Over time, Du Bois grew critical of capitalism, seeing it as a system bound up with racism and imperialism. He argued that capitalism was inherently exploitative and believed that socialism offered a more equitable system that could address racial disparities effectively.

György Lukács (April 13, 1885 C.E. – June 4, 1971 C.E.): Hungarian Marxist philosopher, literary historian, critic, and aesthetician. He was one of the founders of Western Marxism, an interpretive tradition that departed from the Marxist ideological orthodoxy of the Soviet Union. He was Hungarian Minister of Culture of the government of the short-lived Hungarian Soviet Republic (March–August 1919). He preached about the “destruction of the oppressing classes” using the violence of the state

1. Hungarian Soviet Republic: I have heard the story in a number of places that György Lukács, as the Minister of Culture, had intentionally exposed children to deviant sexual material. I’ve even heard that he tried to force kids into sex transition (boys becoming girls and girls becoming boys). I don’t know if this is true or not, as most of the sources that mention this are people and organizations who have an axe to grind against LGBT issues. The leftist website Jacobin does mention that “The Commissariat established a sex education program aimed at schoolchildren — the first of its kind in deeply Christian Hungary” but doesn’t say anything more. This Daily Mail article does claim that György Lukács’s Marxist ideology sought to destroy “old values” but doesn’t confirm that György Lukács was exposing children to sexually deviant material.
   • From the Daily Mail article: “While the book [Michael Löwy’s Georg Lukacs: From Romanticism to Bolshevism] quotes extensively from Lukacs and is well sourced it does not include a direct admission from Lukacs that he was attempting to demoralise Christian society with his education program. This charge seems to stem from the observation of a Yugoslav professor, Victor Zitta. Mr Audritt quotes Michael Lowy, quoting Victor Zitta: “The bourgeois fury and indignation at Lukacs’s profoundly subversive cultural policy has recently found echo in the writings of one Victor Zitta. Portraying Lukacs as a ‘fanatic… bent on destroying the established social order’, Zitta argues that education became ‘something perverse’ under Lukacs’s guidance: ‘Special lectures were organised in school and literature printed and distributed to “instruct” children about free love, about the nature of sexual intercourse, about the archaic nature of the bourgeois family codes, about the outdatedness of monogamy, and the irrelevance of religion which deprives man of all pleasure. Children urged thus to reject and deride paternal authority and the authority of the church, and to ignore precepts of morality’.”
2. False Consciousness: the lower class is unaware of their own oppression due to the ideology (in the Marxist sense) essentially brainwashing them into thinking their lot in life is natural and normal. The kind of happiness that people experience in capitalism (e.g., consumption of commodities) is not a real kind of happiness, but one that results from their false consciousness about how society ought to be.
3. Reification: the process of making things that are not real seem real, such as the capitalist class divisions. Basically the way that the ideology of the dominant ruling class is made so as to seem like it is natural, normal, and necessary.

Antonio Gramsci (January 22, 1891 C.E. – April 27, 1937 C.E.): Italian Marxist philosopher, journalist, linguist, writer, and politician. He wrote on philosophy, political theory, sociology, history, and linguistics.

1. Cultural Hegemony: Describes how states use cultural institutions to maintain power in capitalist societies. Unlike Marx, who focused predominantly on economic structures, Gramsci argued that cultural and ideological supremacy is essential for maintaining the power of the ruling class. Hegemony occurs when the ruling class’s values are perpetuated by cultural institutions such as media, religion, and education, becoming the “common sense” values of all. Thus, the ruling class maintains authority not just through coercion but by shaping the very ideologies and norms of society. Essentially, the dominant ruling class owns the means of cultural production and get to decide what the “correct” beliefs, values, norms, and social mores are.
2. Intellectuals and Education: Gramsci placed a significant emphasis on the role of intellectuals in society. He distinguished between “traditional” intellectuals, who see themselves as autonomous from the ruling class, and “organic” intellectuals, who emerge organically from and are connected to the working class, helping to advance its interests. Gramsci believed that these organic intellectuals are crucial for creating a counter-hegemony that challenges the dominant class’s cultural leadership.
3. State and Civil Society: Gramsci expanded the concept of the state to include “civil society” (i.e., the ensemble of organizations not directly part of the government but which wield cultural, ideological, and moral influence). He argued that true political power requires control not only of the state’s repressive “political society” (police, military, legal system) but also of the consensual activities of civil society.
4. War of Position and War of Maneuver: Gramsci made a critical distinction between the “war of maneuver” (direct, overt conflict as seen in wars and revolutions) and the “war of position” (the struggle to develop a dominant ideological position within civil society). For Gramsci, advanced capitalist societies, where civil society is complex and entrenched, require a “war of position” that precedes any “war of maneuver.” This involves creating alternative cultural and social practices that can form the basis for political revolution.
5. Philosophy of Praxis: Although Gramsci seldom used the term “Marxism,” he referred to his own views as the “philosophy of praxis.” He focused on practical transformation of the world through critical reflection and action, emphasizing the dialectical relationship between theory and practice.

Theodor Adorno (September 11, 1903 C.E. – August 6, 1969): German philosopher, sociologist, psychologist, musicologist, and composer known for his critical theory of society.

1. Negative Dialectics: Seeks to critique the traditional approach of dialectical thinking found in Hegel and Marx, which posits a synthesis arising from the tension between thesis and antithesis. Adorno argues that this approach mistakenly assumes a harmonious resolution is always possible. Instead, negative dialectics emphasizes the persistence of contradictions in society and thought, without necessarily resolving them. This method reflects Adorno’s view that true reality is non-identical to our concepts and that philosophy must strive to express what is left out by such identifications.
2. Culture Industry: Together with Max Horkheimer, Adorno developed the concept of the “culture industry” in their seminal work “Dialectic of Enlightenment.” They argue that popular culture in capitalist societies serves as a tool of social domination and control, where mass-produced cultural goods replicate dominant ideologies and subdue critical thinking. This leads to a passive acceptance of the status quo and a decline in the individual’s capacity for critical reflection.
3. Aesthetics and Art: Adorno placed high value on autonomous art—art that resists forms of commodification and challenges societal norms—as a potential source of critical insights and truths about society. He believed that advanced artworks, particularly those that embrace dissonance and complexity, can reveal societal contradictions and resist the simplifying and reductive forces of the culture industry.
4. Critique of Enlightenment: Adorno critically reexamines the Enlightenment’s project of advancing human reason and autonomy. In “Dialectic of Enlightenment” he contends that Enlightenment rationality, instead of liberating individuals, has led to new forms of domination, epitomized by instrumental reason—the use of reason as a tool for controlling nature and humans. This instrumentalization of reason culminates in its dialectical reversal, where human liberation turns into oppression.
5. Morality and Ethics: In response to the atrocities of the Holocaust, Adorno’s later work explores the possibilities of morality in post-genocide society. His famous dictum, “to write poetry after Auschwitz is barbaric,” underscores the profound ethical and cultural crisis faced by modern civilization. For Adorno, genuine morality must now recognize the depths of human depravity and rethink the bases of ethical life and thinking in light of this recognition.

Max Horkheimer (February 14, 1895 C.E. – July 7, 1973 C.E.): German philosopher and sociologist who was famous for his work in critical theory as a member of the Frankfurt School of social research.

1. Traditional and Critical Theory: lays out a philosophical and methodological foundation for the Frankfurt School’s critical approach to social sciences, highlighting the limitations of traditional theories and advocating for a theory that is dynamic, self-aware, and explicitly aimed at social transformation.
   1. Traditional Theory: Horkheimer characterizes traditional theory as the type of scientific and philosophical inquiry that aims to observe, explain, and predict the world. It operates within the framework of established norms and methodologies, aiming to produce generalized, objective knowledge. This form of theory is prevalent in the natural sciences and has been applied to social sciences, treating society as an object that can be studied detachedly.
   2. Critical Theory: In contrast, critical theory, according to Horkheimer, seeks not only to understand or explain society but to change it. It is inherently reflexive and normative, incorporating a critique of society and its power structures. Critical theory challenges the status quo by examining the underlying societal conditions that give rise to observed phenomena, emphasizing the historical and contextual factors in analysis.
   3. Goals and Purposes: Horkheimer argues that traditional theory is often guided by the interests of social and economic power structures, which influences its objectives and outcomes, potentially reinforcing existing inequalities. Conversely, critical theory aims to liberate human beings from the circumstances that enslave them, advocating for emancipation and enlightenment.
   4. Methodology: Unlike traditional theory, which often isolates variables to understand causal relationships, critical theory engages with the totality of social processes. It argues that individual aspects of society cannot be understood in isolation from the overarching social and historical contexts that shape them.
   5. Interdisciplinary Approach: Critical theory is inherently interdisciplinary, drawing from sociology, philosophy, economics, and history to provide a comprehensive critique of societal issues. This approach contrasts with the often compartmentalized methodologies of traditional theory.
   6. Praxis: A fundamental aspect of critical theory is its commitment to praxis—integrating theory with practice. Horkheimer emphasizes that theory must engage with the real-world struggles for social change, aligning theoretical critique with efforts towards societal transformation.
2. Dialectic of Enlightenment: co-authored by Max Horkheimer and Theodor Adorno, it is both a critical reflection on the history of Western thought and a dire warning about the trajectory of modern society under capitalist modes of production and Enlightenment rationality. Its critique of reason and the culture industry remains influential in contemporary debates on consumer culture, media influence, and the role of technology in society.
   1. Critique of Enlightenment Reason: Horkheimer and Adorno argue that the Enlightenment, which promoted reason as a tool to liberate humanity from superstition and ignorance, has paradoxically ended up reinforcing domination. They assert that the Enlightenment’s drive for mastery and control over nature extends to human nature and society, resulting in a form of reason that suppresses individuality and diversity.
   2. Instrumental Reason: The authors introduce the concept of “instrumental reason,” where reason is used primarily as a tool for achieving practical ends, rather than for pursuing truth or moral values. This utilitarian application of reason leads to a world where everything is measured by its functionality or its ability to serve predetermined ends, ultimately reducing human beings to mere objects or tools within systemic processes.
   3. Culture Industry: Horkheimer and Adorno critically analyze the role of mass media and culture industry in shaping public consciousness. They argue that the culture industry perpetuates social control by promoting a standardization of culture and entertainment. This leads to a passive consumption of culture, which dampens critical thinking and individual expression, reinforcing the status quo.
   4. Myth and Enlightenment: The authors trace the trajectory from myth to enlightenment, suggesting that enlightenment itself reverts to mythology by absolutizing rationality and suppressing other forms of knowledge and belief. This regression results in a new kind of myth-making, where enlightened reason becomes a myth that justifies itself as the only legitimate form of knowledge.
   5. Domination of Nature: A recurring theme in the text is the domination of nature. Horkheimer and Adorno argue that the human endeavor to control and manipulate nature is mirrored in social and political structures that seek to dominate and control individuals. This reflects a broader dialectic wherein enlightenment, originally a liberating force, becomes a mechanism of subjugation.
   6. Adorno’s Aesthetic Theory: While not the central focus of this work, elements of Adorno’s aesthetic theory are present, particularly the idea that authentic art challenges the status quo by resisting commodification and standardization, thus providing a potential space for true enlightenment and resistance against the culture industry.

Herbert Marcuse (July 19, 1898 C.E. – July 29, 1979 C.E.): German-American philosopher, sociologist, and political theorist, associated with the Frankfurt School of critical theory.

1. An Essay on Liberation: people need to have psychopathologies induced in them that make them unable to tolerate liberalism in order for people to take on a “new sensibility,” meaning that they see anything and everything through the lens of Critical Theory. This is why all Critical Theories are said to be negative insofar as they do not submit a vision of their Utopia, but say that Utopia will be what is left standing once liberalism has been completely razed to the ground.
   1. Critique of Advanced Industrial Society: Marcuse critiques advanced industrial societies, which, according to him, manage to contain and suppress revolutionary potential through increasing consumerism, technological advances, and administrative controls. He argues that these societies use comfort, efficiency, and stability to integrate individuals into the existing system of production and consumption, thus diminishing the possibilities for radical change.
   2. New Sensibility and Aesthetics: A significant part of the essay focuses on the emergence of a new sensibility among the youth and marginalized groups, which rejects the prevailing performance principle of capitalism—that is, the societal norms that dictate that the value of an act lies in its success and productivity. Marcuse sees this new sensibility as an aesthetic as well as a political rebellion, which values human liberation, both individual and collective, and seeks to develop new forms of work, ethics, and culture.
   3. Potential for Liberation: Marcuse is optimistic about the potential for liberation from the prevailing capitalist system. He identifies the radical potential in marginalized groups—not traditionally part of the working class as defined by earlier Marxist theorists—as vital to revolutionary change. This includes racial minorities, students, and anti-war demonstrators, whom he sees as outside the stabilizing mechanisms of capitalist society and therefore able to initiate change.
   4. Role of Technology: Unlike many critiques who viewed technology purely as a tool of domination, Marcuse argues that technology, if re-directed from perpetuating consumer culture and capitalist accumulation, has the potential to facilitate liberation. He envisions a society where technology serves to reduce labor time and increase leisure, contributing to human freedom rather than economic exploitation.
   5. Revolutionary Violence: Marcuse discusses the role of violence in the process of liberation. He argues that violence is a necessary part of the struggle against oppressive systems, although he emphasizes that it should be a last resort. He contrasts liberating violence, which aims to end oppression, with the repressive violence used by the state to maintain control.
   6. Beyond Marxism: Marcuse extends traditional Marxist theory by incorporating elements of existentialism, psychoanalysis, and feminism, adapting these to the social and cultural conditions of the 1960s. He calls for a radical re-envisioning of Marxist theory that would better address these new realities.
2. Repressive Tolerance: repression is tolerable if it is done by the left. Ostensibly a critical exploration of the concept of tolerance in modern liberal societies, particularly how it can be manipulated to serve oppressive ends.
   1. Critique of Liberal Tolerance: Marcuse critiques what he sees as the prevailing form of tolerance in liberal societies, which he labels “repressive tolerance.” This form of tolerance, according to Marcuse, allows for the expression and acceptance of a wide range of views, no matter how harmful or unjust, under the guise of freedom of speech. However, it often serves to reinforce established power structures and suppresses genuine opportunities for change by legitimizing oppressive and exploitative systems.
   2. Tolerance as a Political Tool: Marcuse argues that in societies dominated by repressive forces, tolerance becomes a mechanism for maintaining the status quo. He observes that tolerance is extended mainly to thoughts and actions that are inoffensive to these dominant forces, while truly subversive or revolutionary ideas and movements are often not tolerated.
   3. Selective Tolerance: One of Marcuse’s central ideas is the concept of “selective tolerance.” He suggests that tolerance should not be uniformly applied but rather should be selective based on the content and context of what is being expressed. He argues for “intolerance toward regressive and repressive opinions and movements” while advocating for tolerance of progressive, emancipatory movements that challenge oppressive systems.
   4. Repressive vs. Liberating Tolerance: Marcuse makes a distinction between repressive tolerance (which allows oppressive practices under the protection of tolerance) and liberating tolerance (which seeks to restrict oppressive speech and promote liberating ideas). He proposes that society should practice liberating tolerance by limiting toleration of right-wing political movements and extending greater freedom to left-wing movements that aim to promote social change.
   5. Criticism of Neutrality: Marcuse criticizes the concept of neutrality in the administration of tolerance, arguing that neutrality often favors the powerful and sustains social inequities. He challenges the idea that tolerance should be disinterested or neutral, positing instead that it should be a partisan and engaged process aimed at fostering conditions for genuine equality and freedom.
   6. Implications for Democracy: While controversial, Marcuse’s thesis raises important questions about the role of tolerance in a truly democratic society. He suggests that a reevaluation of the principles of tolerance is necessary to prevent democracy from becoming a tool of oppression and to ensure it serves as a means of genuine liberation and equality.

Derrick Bell (November 6, 1930 C.E. – October 5, 2011 C.E.): American lawyer, professor, and civil rights activist. Bell worked for first the U.S. Justice Department, then the NAACP Legal Defense Fund, where he supervised over 300 school desegregation cases in Mississippi.

1. Interest Convergence Thesis: This is the idea that the only time the dominant group (white people) would ever give anything like rights to other races (especially black people) is if it was in their own interest to do so. In other words, the interests of the non-white people who will “benefit” from some policy must converge with the interests of the white dominant class. I put scare quotes around “benefit” because a part of this doctrine is that the non-whites don’t truly benefit, since when the white interests are upheld it is only ever at the cost of the non-whites (it is zero sum). Indeed, Derrick Bell came up with the interest-convergence thesis when he argued that Brown vs. Board of Education case that led to school integration was done for white interests (like, for instance, stemming the tide of Marxism) and only succeeded (as far as black people are concerned) in making racism more hidden.

Richard Delgado (October 6, 1939 C.E. – Present): American legal scholar who teaches civil rights and critical race theory at the University of Alabama School of Law. He has written and co-authored numerous articles and books, many with his wife, Jean Stefancic

Jean Stefancic (January 14, 1940 C.E. – Present): American legal academic, Professor and Clement Research Affiliate at the University of Alabama. She has written numerous books with her husband Richard Delgado.

Angela Davis (January 26, 1944 C.E. – Present): American political activist, philosopher, academic, scholar, and author.

Cornel West (June 2, 1953 C.E. – Present): American philosopher, political activist, social critic, actor, and public intellectual. The grandson of a Baptist minister, West focuses on the role of race, gender, and class in American society and the means by which people act and react to their “radical conditionedness”.

Judith Butler (February 24, 1956 C.E. – Present): American philosopher and gender theorist whose work has influenced political philosophy, ethics, and the fields of third-wave feminism, queer theory, and literary theory.

1. Gender Performativity: One of Butler’s most seminal contributions to gender theory is her concept of performativity, articulated in her 1990 book “Gender Trouble: Feminism and the Subversion of Identity.” Butler argues that gender is not a fixed biological or natural reality but rather something that is performed; it is produced and reproduced through our actions, speech, and behavior in compliance with societal norms and expectations. This performance is iterative and has a social audience, meaning gender identities are sustained through repeated actions over time and can be altered through variations in these performances.
2. Critique of Gender Norms: Butler challenges the traditional notion of gender as a binary (male and female) and argues that such a binary system is exclusionary and oppressive. She suggests that the binary gender framework enforces a restrictive normativity on bodies, defining acceptable identities while marginalizing others that do not conform (such as transgender identities).
3. Subversion of Identity Categories: Central to Butler’s philosophy is the idea that the subversion of established categories and identities can be a form of political resistance. By destabilizing normative concepts of gender and sexuality, Butler believes that individuals can resist oppression and contribute to social change. This is a call for a broader, more inclusive understanding of gender that allows for a multiplicity of identities.
4. Intersectionality: Although not the originator of the term, Butler’s work emphasizes the intersectional nature of identities—how gender intersects with race, class, sexuality, and other markers of difference to create complex matrices of power and oppression. This framework helps to understand how various forms of discrimination and privilege interconnect and affect individuals differently.
5. Body and Materiality: Butler’s later work, such as in “Bodies That Matter: On the Discursive Limits of Sex” (1993), delves into how bodies are shaped and given meaning within specific cultural and historical contexts. Here, she explores how societal norms and discourses materialize the body and thus how certain bodies come to matter socially and politically while others do not.
6. Ethics and Vulnerability: More recently, Butler has focused on themes of ethics, human vulnerability, and precarity. In works like “Precarious Life” (2004) and “Frames of War” (2009), she discusses how political conditions expose certain populations to suffering and neglect, and she calls for a broader ethical responsibility to recognize and respond to the vulnerability of others.

Kimberlé Crenshaw (May 5, 1959 C.E. – Present): American civil rights advocate and a leading scholar of critical race theory. She is a professor at the UCLA School of Law and Columbia Law School, where she specializes in race and gender issues. Probably most widely known for her ideas in so-called intersectionality.

1. Intersectionality: Crenshaw’s most influential contribution is her theory of intersectionality, which she first articulated in 1989. Intersectionality is a framework for understanding how various forms of inequality and discrimination (such as race, gender, class, and sexuality) overlap and intersect in complex ways. Crenshaw argued that traditional feminist and anti-racist discourses often focus on the experiences of white women and black men, respectively, failing to address the unique challenges faced by black women and other minorities who experience both racial and gender discrimination simultaneously.
2. Critique of Single-axis Framework: Crenshaw criticizes single-axis frameworks in legal and social analyses, which examine only one form of identity (such as race alone or gender alone) at a time. This approach, she argues, overlooks the multidimensional nature of lived experiences, particularly for individuals who belong to multiple marginalized groups. She highlights the need for legal and political frameworks that recognize the complexity of these intersections to address the realities of those who experience discrimination on multiple fronts.
3. Structural Intersectionality: Crenshaw’s concept of structural intersectionality examines how the social structures and power systems (like the legal system, labor market, etc.) interact to produce conditions that marginalize individuals along multiple intersecting lines. For example, black women may face distinct employment disadvantages that are not adequately addressed by policies designed to help black men or white women.
4. Political Intersectionality: This aspect of intersectionality looks at how political agendas can either ignore or exacerbate the visibility of certain groups within social movements. Crenshaw discusses how the political strategies of both feminist and anti-racist movements have sometimes marginalized the voices and experiences of black women.
5. Representational Intersectionality: Crenshaw addresses how cultural representations (or lack thereof) of different groups can perpetuate discrimination. This includes the ways in which portrayals in media or literature might reinforce harmful stereotypes or erase the presence and experiences of marginalized groups.
6. Applications of Intersectionality: Beyond theory, Crenshaw applies the concept of intersectionality to various practical contexts, including violence against women, workplace discrimination, and legal justice. She uses intersectionality to analyze both the personal narratives and broader policies affecting individuals at the intersections of race, gender, and other identities.

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Existentialists

Arthur Schopenhauer (February 22, 1788 C.E. – September 21, 1860 C.E.): German philosopher. He is best known for his 1818 work The World as Will and Representation, which characterizes the phenomenal world as the product of a blind noumenal will.

Søren Kierkegaard (May 5, 1813 C.E. – November 11, 1855 C.E.): Danish theologian, philosopher, poet, social critic, and religious author who is widely considered to be the first existentialist philosopher. Kierkegaard’s focus on individual experience, freedom, and the existential aspects of human life had a profound influence on existential philosophy and modern theology. His ideas inspired later existentialists like Jean-Paul Sartre, Albert Camus, and Martin Heidegger.

1. Subjectivity: Kierkegaard is well-known for his assertion that “subjectivity is truth.” He emphasizes the importance of the individual’s subjective experience and perspective, arguing that truth is not merely an objective reality but is also deeply rooted in personal perception and existential commitment.
2. Stages on Life’s Way: Kierkegaard describes three major stages of life that reflect different ways of living and levels of existential awareness: the aesthetic, the ethical, and the religious.
   1. The aesthetic stage is characterized by a pursuit of pleasure and avoidance of boredom, often through the enjoyment of art, romance, and sensory experiences. Individuals in this stage lack a coherent life plan and live impulsively.
   2. The ethical stage is marked by a commitment to moral principles and societal norms. Individuals in this stage make choices based on ethical considerations and strive for a coherent life narrative.
   3. The religious stage, particularly “religiousness A” and “religiousness B” (with B referring to Christian faith), involves a personal and transcendent relationship with God. It is characterized by a leap of faith, where reason cannot lead, and is marked by the acknowledgment of one’s dependence on God and the paradoxes inherent in faith.
3. Leap of Faith: Central to Kierkegaard’s philosophy is the concept of the “leap of faith.” He argues that true faith in God requires a personal decision that cannot be mediated or justified by reason. This leap is not irrational but is beyond rational justification, embracing the absurdity of Christian beliefs (such as the incarnation and resurrection of Christ).
4. Existential Anxiety and Despair: Kierkegaard explores the themes of anxiety and despair, which he sees as inherent to human existence. Anxiety, or “dread,” arises from the realization of one’s possibilities, including the freedom to choose and the responsibility that choice entails. Despair results from not accepting oneself as a being grounded in a relationship with God or from not living authentically according to one’s own principles.
5. Critique of Hegelianism and the Church: Kierkegaard was a vocal critic of Hegelian philosophy and the Danish State Church. He argued that Hegel’s system reduced the individual to a mere part of the historical process, ignoring the importance of personal existence and freedom. His critique of the church focused on its institutionalization of Christianity, which he felt undermined the personal, existential nature of faith.

Friedrich Nietzsche (October 15, 1844 C.E. – August 25, 1900 C.E.): German philosopher, cultural critic and philologist whose work has exerted a profound influence on modern intellectual history. He began his career as a classical philologist before turning to philosophy.

1. Will to Power: Nietzsche proposed the “will to power” as a fundamental driving force in humans, which he believed to be the essence of all life. This concept suggests that the fundamental motive of human beings is not survival or reproduction, but a fundamental will to assert and enhance their power and influence.
2. Übermensch (Overman): One of Nietzsche’s most famous concepts is the Übermensch, which represents an individual who has transcended the conventional boundaries and values of society to create his own values. The Übermensch is an ideal for individuals to aspire to, where one overcomes the herd mentality of mass society to achieve a higher state of being and freedom.
3. Eternal Recurrence: The idea of eternal recurrence is a central thought experiment in Nietzsche’s work. It posits that all events in one’s life will happen an infinite number of times over in exactly the same way. Nietzsche uses this concept to challenge individuals to examine their lives critically: If one had to live the same life over again eternally, would one be satisfied with it?
4. Critique of Morality: Nietzsche critically examines traditional moral values, particularly those rooted in Christianity. He argues that the “slave morality” of Christianity glorifies weakness, humility, and obedience by turning them into virtues, thus suppressing the natural strength and power of the human individual. In contrast, Nietzsche advocates for a “master morality” which values power, nobility, and self-assertion.
5. Aesthetics Over Truth: Nietzsche often emphasized art over truth, arguing that the creation and appreciation of art offer a more fulfilling way to engage with life than the pursuit of objective truth, which he saw as an illusion. Art, for Nietzsche, is a form of metaphysical activity that can imbue life with meaning in the absence of God or absolute truth.
6. Death of God: Nietzsche’s declaration that “God is dead” is one of his most famous and provocative statements, found primarily in his book “The Gay Science” and later elaborated upon in “Thus Spoke Zarathustra.” This statement is often misunderstood as a literal assertion about theological belief, but it is, in fact, a metaphorical expression concerning the decline of traditional Christian values in the modern world and the vacuum it leaves in the moral and existential landscape of society.
   1. Nietzsche saw the death of God as a pivotal, transformative event in human history, which would lead to profound existential challenges. With the collapse of a universally accepted moral order provided by religion, he predicted that society would face a period of nihilism—an absence of meaning, values, and purpose. This nihilism presents both a crisis and an opportunity:
      • Crisis: The loss of absolute values can lead to despair, anomie, and moral disorientation, where “everything is permitted” because no divine commandments or metaphysical truths guide human actions.
      • Opportunity: Nietzsche believed that the death of God would force individuals to reassess the foundations of their values and beliefs, ultimately leading to the creation of new values. This process is necessary for the emergence of the Übermensch, or Overman, who creates meaning and values independent of traditional religious frameworks.

Edmund Husserl (April 8, 1859 C.E. – April 27, 1938 C.E.): German philosopher and mathematician who established the school of phenomenology. In his early work, he elaborated critiques of historicism and of psychologism in logic based on analyses of intentionality.

1. Phenomenology: Husserl developed phenomenology as a rigorous philosophical method aimed at studying the phenomena (the things themselves) as they appear to the consciousness. This method involves “bracketing” or setting aside questions about the existence of the external world and focusing instead on how things appear in one’s experience.
2. Intentionality: One of Husserl’s core ideas is intentionality, the notion that consciousness is always consciousness of something. This concept, which he borrowed and expanded from his mentor Franz Brentano, means that all acts of consciousness (whether perceiving, imagining, or thinking) are directed toward objects. Husserl’s analysis of intentionality is a central component of his argument that consciousness and experience are structured in ways that can be systematically explored and described.
3. Eidetic Reduction: Husserl introduced the concept of eidetic reduction, which involves stripping away the empirical aspects of phenomena to reveal their essential structures through imaginative variation. This method is used to identify the invariant features of experiences, such as the essence of what it means to perceive something or to imagine something.
4. Transcendental Phenomenology: Later in his career, Husserl developed the idea of transcendental phenomenology, which he saw as a way to investigate the conditions that make knowledge and experience possible. This involves examining the role of the experiencing subject, not merely as an empirical ego but as a transcendental ego, which is the source of all meanings and the condition for the possibility of experience.
5. Constitution: Husserl’s concept of constitution refers to the way in which phenomena are constituted in conscious experience. He explored how objects are constituted differently in various types of experiences, such as perception, memory, and imagination. This aspect of his philosophy emphasizes the active role of consciousness in organizing and interpreting sensory data to form coherent objects of experience.
6. Crisis of the European Sciences: In his later work, particularly in “The Crisis of European Sciences and Transcendental Phenomenology” Husserl argued that the sciences had lost touch with the lifeworld (Lebenswelt), the world of everyday, lived experience that provides the ground for scientific inquiries. He called for a return to the lifeworld as a way to ground the sciences in human experience and to renew their meaning for human existence.

Karl Jaspers (February 23, 1883 C.E. – February 26, 1969 C.E.): German-Swiss philosopher and psychiatrist who had a significant impact on modern theology, psychiatry, and philosophy. Originally trained as a medical doctor, Jaspers turned to philosophy in his 30s, and his work is often associated with existentialism, though he termed his philosophy “Existenzphilosophie.” Jaspers’ philosophy explores themes of freedom, transcendence, the limits of human knowledge, and the existential conditions of modern human life.

1. Existenz: Jaspers coined the term “Existenz” to describe the inner, subjective experience of individual existence. He distinguishes between “Dasein,” everyday existence, and “Existenz,” a more profound mode of being that is realized only when individuals confront their own limits and possibilities. Existenz is an authentic state where individuals face the most profound aspects of life, such as freedom, decision, and responsibility.
2. Transcendence: Central to Jaspers’ thought is the concept of transcendence, which refers to that which lies beyond the limits of the empirical world and human understanding. He argues that while transcendence cannot be known through scientific means, it is experienced through philosophical faith and existential awareness. This aspect of his philosophy touches on the metaphysical and spiritual dimensions of human life.
3. The Limits of Knowledge: Jaspers was deeply influenced by Kantian epistemology, specifically the idea that human understanding is limited by the categories of thought. He believed that while science and reason are crucial, they have inherent limits. For Jaspers, philosophy’s role is to illuminate these limits and explore the implications for human existence.
4. Ciphers of Transcendence: Jaspers introduced the idea of “ciphers” to describe symbols or events in the world that point toward hidden meanings or metaphysical truths. These ciphers do not have fixed meanings but must be interpreted by each individual, offering a personal glimpse into the transcendent.
5. The Periechontology: This is Jaspers’ framework for understanding Being, which encompasses all modes of existence and non-existence, including empirical existence (Dasein), existential possibility (Existenz), and transcendence. This framework attempts to describe the totality of human experience and the world.
6. Communication and Philosophical Faith: Jaspers placed a strong emphasis on communication as essential for achieving Existenz. He believed that truthful and open dialogue could lead individuals toward self-realization and ethical living. Furthermore, philosophical faith, according to Jaspers, is an individual’s leap into believing in transcendence and the greater dimensions of existence, which cannot be conclusively proven but can be intuited and experienced.

Martin Heidegger (September 26, 1889 C.E. – May 26, 1976 C.E.): German philosopher who is best known for contributions to phenomenology, hermeneutics, and existentialism. He is among the most important and influential philosophers of the 20th century.

Jean-Paul Sartre (June 21, 1905 C.E. – April 15, 1980 C.E.): One of the key figures in the philosophy of Existentialism, a French playwright, novelist, screenwriter, political activist, biographer, and literary critic, as well as a leading figure in 20th-century French philosophy and Marxism.

1. Being and Nothingness: one of Sartre’s earlier works that covers an extensive philosophical examination of the nature of being, consciousness, and existence from an existential perspective.
   1. Phenomenological Ontology: Sartre builds on the phenomenological method, particularly as developed by Edmund Husserl and Martin Heidegger, to explore the nature of being. He distinguishes between two types of being: “being-in-itself” (être-en-soi), which is the being of objects that exist independently of consciousness, and “being-for-itself” (être-pour-soi), which is the being of consciousness which is not identical with its essence and is defined by its self-awareness.
   2. Nothingness and Consciousness: A central argument in Sartre’s work is that nothingness is a fundamental characteristic of consciousness. Consciousness negates, or “nihilates,” itself from being-in-itself, creating an internal lack, which Sartre describes as “nothingness.” This nothingness allows for freedom, as it means that our essence is not predetermined—we are free to define ourselves through our actions.
   3. Freedom and Responsibility: For Sartre, humans are condemned to be free. Since there is no Creator, and thus no predetermined essence or purpose to our lives, we must choose our essence at every moment through our actions. This radical freedom is also a source of existential angst, as it comes with the responsibility for these choices, which define who we are.
   4. Bad Faith: Sartre explores the concept of bad faith, where individuals deny their freedom and responsibility by adopting false values or deceiving themselves about their true nature or motives. This is often an attempt to escape the anxiety of freedom by pretending that one’s actions are determined by external circumstances or societal roles.
   5. The Look: Another significant concept in “Being and Nothingness” is the idea of “the Look” of the Other. Sartre explains how the awareness of another person’s gaze can fundamentally alter the way we see ourselves. Through the Other’s look, we become objectified and aware of ourselves as objects in the world. This leads to a fundamental shift in our experience of ourselves and our freedom.
   6. Relationships and Conflict: Sartre argues that relationships are inherently conflictual because each person tries to assert their freedom while negating the freedom of the other. This leads to various forms of conflict and domination, as illustrated in his discussion of love, masochism, and sadism.
   7. Existential Psychoanalysis: Sartre proposes an existential version of psychoanalysis that seeks to uncover not unconscious motivations but the individual’s fundamental project and the choices that define their being.
2. Existentialism is Humanism: serves as an accessible introduction to his existentialist philosophy.
   1. Existence Precedes Essence: Sartre’s central claim in existentialist philosophy is that “existence precedes essence.” This means that, for human beings, there is no predefined pattern that anyone must fit into. People are first thrown into the world, exist, and only afterwards define themselves. As there is no God to design human nature, humans must create their own essence through their actions.
   2. Freedom and Responsibility: According to Sartre, without a predetermined nature, humans are radically free to make their own choices. However, this freedom is also a kind of burden because it carries with it the responsibility of defining one’s essence and influencing the world. Every action a person takes not only defines their own essence but also suggests a vision of what a human being should be like. Therefore, Sartre emphasizes that we are responsible for all humanity.
   3. Subjectivity: In explaining his philosophy, Sartre asserts the importance of individual subjectivity, which allows each person to understand themselves from the unique perspective of their own experiences. He argues that this subjectivity is what makes human beings truly human, as it is the basis of our freedom and responsibility.
   4. Condemned to be Free: A famous notion from Sartre is that humans are “condemned to be free.” Since there is no creator or predetermined human nature, each individual is thrown into the world, forced to define themselves, and responsible for every action. This concept underscores the inherent anxiety and anguish of existential freedom.
   5. Bad Faith: Sartre reiterates his concept of bad faith (mauvaise foi), the act of deceiving oneself about the reality of one’s situation or the freedom and responsibility inherent to it. Individuals engage in bad faith to escape the existential anxiety produced by absolute freedom.
   6. Response to Criticisms: Sartre addresses criticisms that existentialism promotes despair, is quietistic, ignores the solidarity of human beings, and is a form of subjectivism. He counters these by emphasizing existentialism’s inspiring call for each person to make meaning of their life through actions, its acknowledgment of every individual’s impact on all humanity, and its foundation in the objective state of human freedom and responsibility.

Simone de Beauvoir (January 9, 1908 C.E. – April 14, 1986 C.E.): French existentialist philosopher, writer, social theorist, and feminist activist.

1. Existentialism: She extends existentialist thought by applying it to the analysis of gender and the social condition of women. Her existentialist approach emphasizes individual freedom, responsibility, and the idea that one is not born but rather becomes who they are through their choices and actions.
2. The Second Sex: This seminal work is where de Beauvoir outlines her most influential ideas. She introduces the famous statement, “One is not born, but rather becomes, a woman,” challenging the notion that gender roles are inherent or biologically determined. She argues that society constructs women as the “Other,” defining them solely in relation to men. This “Othering” limits women’s freedom and possibilities, relegating them to a secondary position in society.
3. Ethics of Ambiguity: In her work “The Ethics of Ambiguity,” de Beauvoir explores the existentialist dilemma of freedom and the inherent ambiguity of the human condition. She argues that individuals must navigate the tensions between their own subjective experiences and the objective world, making choices without clear moral absolutes. This work emphasizes the importance of taking responsibility for one’s actions and creating meaning through active engagement in the world.
4. Oppression and Liberation: De Beauvoir’s philosophy includes a profound critique of various forms of oppression, not limited to gender. She examines how economic, social, and racial factors intersect with gender, contributing to a complex matrix of domination. Her feminist theory calls for the liberation of women through gaining awareness of their oppression, rejecting the role of the “Other,” and asserting themselves as free individuals.
5. Feminist Ethics: De Beauvoir advocates for an ethics that acknowledges the difference and rejects the idea of an essential nature for men and women. Her ethical framework encourages a continuous striving towards genuine equality, where individuals of all genders can freely define themselves. She highlights the importance of mutual recognition and respect in personal relationships and societal structures.

Albert Camus (November 7, 1913 C.E. – January 4, 1960 C.E.): Algerian-born French philosopher, author, and journalist. He was awarded the 1957 Nobel Prize in Literature at the age of 44, the second-youngest recipient in history. His works include The Stranger, The Plague, The Myth of Sisyphus, The Fall, and The Rebel.

1. The Myth of Sisyphus: discusses Camus’ view of the absurd as a fundamental condition that defines the human experience. His call to accept the absurd, and to continue living with vigor and rebellion, offers a way to construct a meaningful life from personal freedom and choice despite the indifference of the universe.
   1. The Absurd: Camus begins by confronting what he considers the most important philosophical question: the problem of suicide. He asks whether life is worth living if it lacks inherent meaning. This question leads him to the concept of the absurd, which arises from the confrontation between human beings, who inherently seek meaning and order, and an indifferent, chaotic universe that offers none.
   2. Human Response to Absurdity: Camus argues that once we recognize the absurdity of life, we must decide how to respond to it. He rejects suicide as a response, arguing that it only exacerbates the absurd by seeking escape from it. Instead, he advocates for a life lived fully in the acknowledgement of and confrontation with the absurd.
   3. Rebellion Against the Absurd: Central to Camus’ philosophy is the notion of rebellion. He encourages a defiant response to the absurdity of existence, suggesting that one should live without appeal to a higher meaning, embracing life as it is. This rebellion is not about hope for a better future but about the continuous struggle against the absurd, finding personal meaning in engagement with life itself.
   4. The Myth of Sisyphus: The essay concludes with the myth of Sisyphus, a figure from Greek mythology who was condemned by the gods to roll a boulder up a hill only for it to roll back down each time he neared the top. Camus uses Sisyphus as a metaphor for human efforts and persistence in the face of the absurd. He famously declares that “one must imagine Sisyphus happy” as he accepts his eternal task without hope, finding satisfaction in his rebellion and struggle.
   5. Creation of Meaning: Camus suggests that while the universe might be indifferent and absurd, individuals have the power to create their own meaning. By acknowledging the absurd and continuing to live with passion, integrity, and defiance, one constructs a life that is rich and rewarding in its own terms.
   6. Philosophical Suicide: Camus also discusses the concept of “philosophical suicide,” where one denies the absurd through false beliefs or illusions. He criticizes existential thinkers who, in his view, do this by turning to God or a higher power as a solution to the absurd, thereby abandoning reason and genuine confrontation with life’s lack of inherent meaning.

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Postmodernists

Michel Foucault (October 15, 1926 C.E. – June 25, 1984 C.E.): French philosopher, historian of ideas, writer, political activist, and literary critic. Foucault’s theories primarily address the relationship between power and knowledge, and how they are used as a form of social control through societal institutions.

1. Knowledge and Power: Foucault’s most influential idea is perhaps the relationship between knowledge and power. He argued that they are not independent but rather deeply intertwined. Knowledge is not merely used for exerting power; rather, power relations give rise to different types of knowledge, and knowledge, in turn, reinforces power structures. This mutual reinforcement he describes as “power/knowledge.”
2. Discourse: Foucault’s concept of discourse is central to his thinking. He defined discourse as systems of thoughts composed of ideas, attitudes, courses of action, beliefs, and practices that systematically construct the subjects and the worlds of which they speak. Foucault argued that discourses are powerful in that they can both enable and constrain truth, knowledge, and meaning, effectively shaping reality.
3. Historical Epistemology: Also known as “archaeology” in his earlier works, Foucault’s method involves the historical analysis of the epistemic context within which knowledge is produced. He looked at how different periods in history had underlying epistemological assumptions that determined what could be known and how ideas were systematically formed and accepted as truth.
4. Genealogy: Later in his career, Foucault developed a method he called “genealogy,” influenced by Nietzsche. Genealogy was used to study the historical origins of societal norms and ideas, specifically how they evolved not linearly or progressively but through conflicts, contradictions, and diverse influences. This method focuses particularly on the role of power in shaping what we consider truth and knowledge.
5. Surveillance and Discipline: In his book “Discipline and Punish,” Foucault explored the development of modern disciplinary methods that regulate the body and behavior of individuals within societal institutions, such as prisons, schools, and hospitals. He introduced concepts like the “panopticon,” a design for prisons that allows inmates to be constantly visible to a central watchtower, metaphorically illustrating modern society’s control and surveillance mechanisms.
6. Governmentality: In his later lectures, Foucault developed the concept of governmentality to explain how societies are governed in a broader sense than overt political rule. This includes the techniques and strategies by which a society is rendered governable, from the level of the state down to individual self-regulation.
7. Sexuality and the Self: Foucault also extensively explored the history of sexuality and how sexual norms have been developed and regulated by power. In his later work, he was increasingly interested in the concept of “care of the self,” a practice from antiquity that involves the ethical formation of oneself as a subject through practices of freedom.
8. Biopower: Introduced primarily in his lectures and further developed in his book “The History of Sexuality, Volume 1: The Will to Knowledge” biopower refers to the ways in which power affects individual and collective life processes.
   1. Regulation of Populations: Biopower focuses on the management and regulation of populations rather than just disciplining individual bodies. It involves an array of authorities and institutions employing statistical and regulatory measures to manage the birth rate, mortality rate, health, life expectancy, and other factors related to population at a macro level. This form of power is concerned with optimizing life and its capacities rather than merely repressing it.
   2. Normalization and Health: Biopower extends into numerous aspects of everyday life through the promotion of norms related to health, hygiene, and acceptable behavior. Public health campaigns, sexual education, and norms around family and reproduction are examples where biopower operates to normalize certain behaviors and practices, often justified under the guise of “what is healthy.”
   3. Technologies of Power: Foucault argues that biopower operates through technologies of power that encompass both “disciplinary” mechanisms that target individual bodies (making them more obedient and useful) and “regulatory” controls that focus on populations (ensuring mass normalization). These technologies can be seen in medical institutions, surveillance practices, welfare systems, and public health policies.
   4. Biopolitics: Closely associated with biopower is the concept of biopolitics, which refers to the strategies and mechanisms through which human life processes are managed under regimes of authority over knowledge, power, and the processes of subjectivation. Biopolitics thus deals with the administration of life and the entry of life into history, that is, the ways in which life itself becomes a political issue.
   5. Impact on Identity and Subjectivity: Through the mechanisms of biopower, individuals become subjects who are not only subjected to someone else by control and dependence but are also tied to their own identity and consciousness. Thus, biopower is integral to the formation of subjectivity in modern societies.
   6. Ethical and Political Implications: The exercise of biopower raises profound ethical and political questions about the extent of state control over personal and biological aspects of life. Issues such as reproductive rights, genetic engineering, euthanasia, and rights to health care are deeply entangled in the dynamics of biopower.

Jean-Francois Lyotard (August 10, 1924 C.E. – April 21, 1998 C.E.): French philosopher, sociologist, and literary theorist. His interdisciplinary discourse spans such topics as epistemology and communication, the human body, modern art and postmodern art, literature and critical theory, music, film, time and memory, space, the city and landscape, the sublime, and the relation between aesthetics and politics. He is best known for his articulation of postmodernism after the late 1970s and the analysis of the impact of postmodernity on the human condition.

1. Critique of Meta-narratives (Grand Narratives): Lyotard is perhaps best known for his critique of meta-narratives or grand narratives—those overarching stories and ideologies that societies tell themselves to legitimize knowledge, truth, and cultural norms. According to Lyotard, these grand narratives (such as the Enlightenment’s progress of reason, Marxism’s class struggle, or Christianity’s salvation history) no longer suffice in the postmodern world because they fail to account for the multiplicity and diversity of people’s experiences. He argues that these narratives have lost their credibility, regardless of what mode of discourse they employ.
2. The Postmodern Condition: In “The Postmodern Condition” Lyotard analyzes the state of knowledge in the most developed societies. He argues that the age of postmodernity is characterized by the collapse of these grand narratives, leading to a crisis in the legitimacy of all knowledge. This condition reflects a broader cultural and intellectual crisis, wherein skepticism and relativism prevail over the confidence in historical progress and truth.
3. Language Games: Borrowing from Ludwig Wittgenstein’s concept of language games, Lyotard asserts that all discourse is composed of disparate sets of language games, each with its own rules and conventions. Knowledge then becomes a matter of navigating between these different games, rather than discovering some objective truth. The emphasis shifts from searching for universal truth to validating knowledge through performance within these language games.
4. Differend: In his later work “Differend: Phrases in Dispute” (1983), Lyotard introduces the concept of the differend, which refers to a dispute between parties where there is no common ground or rule of judgment that both parties can agree on. A differend occurs when the language games of the parties involved are so different that there is no way to equitably resolve the dispute because there is no higher meta-language that can encompass both sets of presuppositions and values.
5. Paralogy: Lyotard promotes the idea of paralogy, or the production of dissensus and innovation in language games. Paralogy is about finding ways to instigate differences and transformations within the rules of language games, thereby allowing new ideas and creative solutions to emerge. It contrasts with performativity, which emphasizes efficiency and control, typical of technological and capitalist systems.

Jacques Derrida (July 15, 1930 C.E. – October 2004 C.E.): Algerian-born French philosopher best known for developing a form of semiotic analysis known as deconstruction, which he analyzed in numerous texts, and developed in the context of phenomenology. He is one of the major figures associated with post-structuralism and postmodern philosophy.

Jean Baudrillard (July 27, 1929 C.E. – March 6, 2007 C.E.): French sociologist, philosopher and cultural theorist. He is best known for his analyses of media, contemporary culture, and technological communication, as well as his formulation of concepts such as simulation and hyperreality. He analyzes media, contemporary culture, and technological communication. Baudrillard’s work is often associated with postmodernism, though he described his own approach as part of the broader category of post-structuralism. His ideas about simulation, hyperreality, and the interplay between technology, symbols, and society are central to his philosophical inquiry.

1. Simulacra and Simulation: Baudrillard is perhaps most famously known for his concept of simulation and simulacra, which he elaborates in his seminal work “Simulacra and Simulation” (1981). In this work, he argues that in contemporary society, simulacra, or copies without originals, have replaced the real. This occurs in a progression of the image: from representing reality, to masking and perverting it, to pretending to be real, and finally to bearing no relation to reality whatsoever. As a result, reality and representation become blurred.
2. Hyperreality: Connected to his theories of simulation, Baudrillard’s concept of hyperreality describes a state where the distinction between reality and a simulated copy is eroded. In hyperreality, representations or simulations of reality come to be perceived as more real than reality itself, effectively replacing the real with a selection of signs or images that are taken as truth.
3. Media and the Masses: Baudrillard was critical of the role of mass media in society. He believed that media circulates signs and symbols that create a system of meaning devoid of substance or depth, a process that contributes to the mass manipulation of society. He argued that media communication results in the extermination of meaning and flattens out critical, political, and social discourse.
4. Consumer Society: In his earlier work, like “The System of Objects” (1968) and “The Consumer Society” (1970), Baudrillard explores the nature of consumer culture in the West. He critiques the way objects are consumed not merely for their utility but for their symbolic value and their ability to communicate status and identity.
5. Fatal Strategies and the Object: In later works such as “Fatal Strategies,” Baudrillard reflects on the idea that objects can rebel against their subjugation by becoming absurd or hyperreal, thereby challenging the systems of control and meaning imposed by society. He suggests embracing irrationality, illusion, and reversibility in strategies that subvert traditional structures of power and meaning.

Henri Bergson (October 18, 1859 C.E. – January 4, 1941 C.E.): for both Bergson and Deleuze, and to some extent Jaspers, I didn’t have a good school of thought to place them. An argument could be made that they were existentialist, an argument could be made that they were analytic, and an argument could be made that they were postmodern. And so, I just had to make a decision, which ended up being here at the bottom of the postmodern school of thought.

Gilles Deleuze (January 18, 1925 C.E. – November 4, 1995 C.E.): French philosopher who, from the early 1950s until his death in 1995, wrote on philosophy, literature, film, and fine art. His most popular works were the two volumes of Capitalism and Schizophrenia: Anti-Oedipus and A Thousand Plateaus, both co-written with psychoanalyst Félix Guattari.

1. Difference and Repetition: One of Deleuze’s most significant contributions is his book “Difference and Repetition” where he presents a critique of the traditional emphasis on identity and sameness in Western philosophy. Deleuze argues for a concept of difference that is not derivative of sameness but is primary and intrinsic. This emphasis on difference and becoming over static being is a central theme in his work.
2. Rhizome: In collaboration with Guattari, Deleuze develops the concept of the “rhizome” in “A Thousand Plateaus.” A rhizome is a metaphor derived from botany, describing root structures that spread horizontally, like grass or ginger. In contrast to hierarchical, tree-like structures (arborescent), rhizomes are non-hierarchical and non-linear, allowing for multiple, non-predetermined entry and exit points in data representation and interpretation. This model is used to describe knowledge and social systems that are open, interconnected, and horizontal.
3. Desire and Deterritorialization: Deleuze and Guattari redefine the concept of desire in “Anti-Oedipus,” opposing the psychoanalytic interpretation of desire as lack. Instead, they view desire as a positive, productive force of social and political significance. They introduce the concept of deterritorialization, which refers to the fluidity of boundaries and the escape from rigid structures in both personal and social contexts.
4. Body without Organs: Another key concept is the “Body without Organs” (BwO), which describes a state of being that rejects organization into hierarchical structures. The BwO seeks to experiment with and explore the limits of what a body can do, emphasizing fluidity, change, and the continuous creation of new possibilities.
5. Nomadology and Smooth Space: Deleuze and Guattari contrast “smooth” and “striated” space in their geopolitical analysis. Smooth space is occupied by the “nomad,” a figure that moves freely without permanent ties, while striated space is segmented and regulated. This distinction is used to analyze state power, control mechanisms, and resistance strategies.
6. Immanence: Throughout his work, Deleuze emphasizes the concept of immanence, the idea that existence is contained wholly within the natural world, rejecting any transcendence beyond it. This forms the basis of his critique of traditional metaphysics and his development of a philosophy based on pure immanence.

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Structuralism and Semiotics

Ferdinand de Saussure (November 26, 1857 C.E. – February 22, 1913 C.E.): Swiss linguist, semiotician and philosopher.

1. Semiotics: To give an oversimplified description, semiotics is a theory in linguistics (sometimes also called semiology, and is most often associated with the structuralism of Claude Lévi-Strauss), most famously explicated by Ferdinand de Saussure and Charles Sanders Peirce. In broad strokes, semiotics says that language is structural in that it is dependent on the rest of the language for its meaning (a single word doesn’t have any intrinsic meaning outside the context of the rest of a language; in other words, it is holistic). Saussure puts it like this: “Language is a system of interdependent terms in which the value of each term results solely from the simultaneous presence of the others … concepts are purely differential and defined not by their positive content but negatively by their relations with the other terms of the system.”
2. Semiotics is also known for its signifier and signified (the “sound-image” and “concept” respectively) distinction, where the former is the “symbol” (usually meaning words, though depending on the scholar it can be interpreted more broadly) and the signified is what the signifier points to (it is the meaning of the signifier, i.e., the concept). Notably what is missing in the signifier and signified (particularly in Saussurean semiotics) is the physical referent “out there” in the real world; all we have is the “symbol” or “sound-image” and the concept, or the way that the “sound-image” is understood. Whether Saussure thought a language could be understood without referent at all or whether he was simply bracketing reference for methodological purposes is a point of debate, but Storm takes the interpretation that Saussure was methodologically bracketing reference in order to study the structure of language itself.
3. In Saussurean semiotics, the signifiers tend to be words belonging only to humans. Biosemiotics brings in signifiers (and the corresponding signified) from plants, animals, and other non-linguistic sources. It is now well-attested that many animal species use vocalizations and gestures to communicate. Additionally, organisms like ants use pheromones, bees use a kind of “dance”, and plants communicate through chemicals as well.

Charles Sanders Peirce (September 10, 1839 C.E. – April 19, 1914 C.E.): American philosopher, logician, mathematician and scientist who is sometimes known as “the father of pragmatism”.

1. Pragmatism: Peirce’s most influential contribution to philosophy is the development of pragmatism, a philosophical approach that evaluates theories or beliefs in terms of the success of their practical applications. He introduced the “pragmatic maxim,” which suggests that the meaning of a concept or proposition lies in its observable practical effects. Essentially, to understand what a thought means, we should consider what practical consequences might logically result from the truth of that thought.
2. Theory of Signs (Semiotics): Peirce developed a complex theory of signs, which he called semiotics. According to Peirce, a sign is something that stands to somebody for something in some respect or capacity. He delineated three types of signs: icons (which resemble their objects), indices (which are directly connected to their objects), and symbols (which are related to their objects by convention). This triadic relation (sign, object, and interpretant) is fundamental to understanding all communication and cognition.
3. Fallibilism: Peirce advocated for fallibilism, the idea that human beings could never attain absolute certainty concerning questions of fact. He argued that all our beliefs are subject to doubt and correction. This perspective aligns with his broader view that science and inquiry are inherently iterative processes, always open to revision and dependent on new evidence.
4. Philosophy of Science: Peirce was deeply involved in the philosophy of science, emphasizing the importance of the scientific method for advancing knowledge. He argued that inquiry depends on the irritation of doubt and ceases once a belief is settled. His method of inquiry highlighted the communal nature of science, where consensus among informed researchers leads to the establishment of real truths.
5. Metaphysics: In metaphysics, Peirce developed a theory known as synechism, which promotes the idea of continuity. He opposed Cartesian dualism and other forms of reductionism; instead, he argued for the continuity of the mental and the physical, suggesting that reality is fundamentally characterized by gradualism and continuity rather than dichotomy and discontinuity.
6. Categories of Experience: Peirce also introduced a categorization of universal concepts, known as his theory of categories. He proposed three fundamental categories: Firstness (the mode of being which is such as it is, positively and without reference to anything else), Secondness (the mode of being which is such as it is, with respect to a second but regardless of any third), and Thirdness (the mode of being that is such as it is, in bringing a first and second into relation to each other).

Claude Lévi-Strauss (November 28, 1908 C.E. – October 30, 2009 C.E.): French anthropologist and ethnologist whose work was key in the development of the theories of structuralism and structural anthropology.

1. Structuralism: Lévi-Strauss is best known for developing the approach of structuralism, which he applied to anthropology. Structuralism seeks to understand the underlying structure of cultural systems, such as language, kinship, and myth. He believed that all elements of human culture, including myths and social organizations, are made up of underlying structures that are universal to human cognition but manifest differently across cultures.
2. The Study of Myths: Lévi-Strauss’s analysis of myths is perhaps his most significant contribution to anthropology. In his “Mythologiques” series, he proposed that myths from different cultures, though varied in their content and expression, exhibit similar structures and patterns. By analyzing these structures, he argued that one could gain insight into the universal aspects of human thought and the unconscious processes that shape culture.
3. Binary Oppositions: A key aspect of Lévi-Strauss’s structuralism is his focus on binary oppositions — conceptual pairs such as culture/nature, raw/cooked, or life/death. He argued that the human mind tends to think in binary terms and that these oppositions are fundamental in creating meaning within a culture. The resolution of conflicts between these opposites often forms the basis of mythological narratives and social norms.
4. The Savage Mind: In his work “The Savage Mind,” Lévi-Strauss discusses the intellectual processes of “primitive” peoples, arguing against the idea that they are less complex or logical than those of “civilized” societies. He introduced the concept of “bricolage” – the skill of using whatever is at hand to create something new, which he likened to the way in which mythical thought is constructed.
5. Critique of Modernity: Lévi-Strauss was critical of modern civilization, particularly its destructive impact on the environment and indigenous cultures. He believed that the advance of global modernization leads to a reduction in human diversity and richness of cultural expression.

Roland Barthes (November 12, 1915 C.E. – March 26, 1980): French literary theorist, essayist, philosopher, critic, and semiotician. His work engaged in the analysis of a variety of sign systems, mainly derived from Western popular culture.

1. Mythologies: In his influential book “Mythologies” Barthes explores how societal norms and values are constructed through what he calls “myths,” or cultural symbols and narratives. He analyzes everyday objects and images from French culture as systems of signs that do ideological work, transforming history into nature, and thus making the cultural seem natural. This demystification of taken-for-granted phenomena shows how they reinforce certain values and social norms.
   1. Myth as a Semiotic System: Barthes expands the notion of myth beyond traditional folklore or religious narratives, defining it as a second-order semiotic system. In this framework, a myth is a mode of signification, a form of communication that delivers a cultural message. For Barthes, everything can be a myth provided it is conveyed by a discourse. Myth is not defined by the object of its message but by the way it utters this message.
   2. Depoliticization of Culture: Barthes argues that myths function to naturalize cultural and historical values, turning them into innocuous, taken-for-granted truths. This process strips away the history and politics from cultural signs, making ideological messages appear as natural, inevitable aspects of everyday life.
   3. Bourgeois Culture as Dominant Ideology: Many of the myths Barthes analyzes propagate bourgeois values. For example, professional wrestling, often considered low culture, is portrayed as an exaggerated spectacle of good vs. evil, reflecting and reinforcing certain societal norms and ideologies about justice, heroism, and morality.
   4. Myth Today: The concluding essay, “Myth Today,” provides a theoretical framework for the entire collection. Here, Barthes elaborates on his semiotic theory of myth. He describes how myths transform history into nature, thereby depoliticizing discourse. According to Barthes, mythological signs function by emptying signs of their history and filling them with a universal meaning that seems natural and given. This process masks the underlying power structures that myths serve to perpetuate.
   5. Barthes’ analysis shows how semiotic systems shape our perception of the world, subtly influencing our beliefs and behaviors without our conscious awareness. The work encourages readers to look beyond the surface meanings of cultural phenomena to understand the deeper ideological manipulation at play.Barthes’ critique of everyday cultural “myths” challenges us to question the ‘naturalness’ of things we take for granted. This questioning is crucial for developing a critical awareness of how media and culture influence our understanding of the world.
2. Death of the Author: In his essay “The Death of the Author” Barthes challenges traditional literary criticism’s practice of interpreting texts by considering the intentions and biographical context of the author. He argues that once a text is created, the author’s intentions should be set aside, allowing the text to stand alone and be interpreted by readers, who create their own meanings. This marks a shift from viewing the author as the source of meaning to focusing on the reader and the text itself.
   1. Author’s Authority: Barthes criticizes the practice of interpreting texts by considering the author’s intentions as the definitive explanation of what the text “really means.” He sees this as limiting since it places the author in a position of ultimate authority over the text, overshadowing other interpretations.
   2. Author as a Scripter: Instead of viewing the author as the creator of sovereign meanings, Barthes suggests that the author is merely a “scriptor” — a vehicle through which narratives and ideas pass. The scriptor disappears in the writing process, leaving behind text that stands on its own.
   3. Role of the Reader: For Barthes, the reader plays a crucial role in the production of meaning. He argues that a text achieves its full meaning through the act of reading, and each reader brings their unique interpretation to the text, thus creating its meaning anew. In this sense, the text is more like a fabric of quotations, drawn from innumerable centers of culture, rather than a reflection of a single individual’s thoughts or intentions.
   4. Multiplicity of Meanings: The essay promotes the idea that texts can have multiple, potentially infinite interpretations. Since the author’s intent is disregarded, each reader’s encounter with the text might yield different insights, shaped by their cultural background, personal experiences, and individual psyche.
3. The Pleasure of the Text: In this work, Barthes distinguishes between two modes of reading: “text of pleasure” and “text of bliss.” The text of pleasure is comfortable and conforms to cultural norms, while the text of bliss disturbs, challenges, and unsettles the reader’s historical, cultural, or psychological assumptions. This concept explores how texts interact with the emotions and intellect of the reader, emphasizing the physical and experiential aspects of reading.
4. Semiotics: Throughout his career, Barthes was deeply engaged with the study of signs and the systems in which they operate, known as semiotics. He analyzed how meanings are constructed and conveyed through signs, extending this method beyond language to include images, fashion, and cultural behaviors.
5. Structuralism and Beyond: Although Barthes started within the structuralist tradition, which seeks to identify the structures underlying cultural phenomena, his later work moved towards post-structuralism. He became more interested in the ambiguities and contradictions in texts, the interplay of meanings, and the role of the reader in constructing meanings, which cannot be fully controlled by any underlying structures.
6. Camera Lucida: In this meditation on photography, Barthes explores the nature of photographs and their effect on the viewer. He introduces the concepts of “studium” and “punctum.” Studium refers to the cultural, linguistic, and political interpretation of a photograph, while punctum is a personal, often poignant detail that grabs the viewer’s attention and provokes a strong emotional response.

Julia Kristeva (June 24, 1941 C.E. – Present): Bulgarian-French philosopher, literary critic, semiotician, psychoanalyst, feminist, and, most recently, novelist. Her sizeable body of work includes books and essays which address intertextuality, the semiotic, and abjection, in the fields of linguistics, literary theory and criticism, psychoanalysis, biography and autobiography, political and cultural analysis, art and art history. She is prominent in structuralist and poststructuralist thought. 

1. Intertextuality: Kristeva introduced the concept of intertextuality, which suggests that a text is not an isolated work but is made up of a mosaic of quotations; any text is the absorption and transformation of another. This idea expands the scope of literary analysis to include the various cultural, social, and historical contexts within which a text is written and read.
2. Semiotic and Symbolic: In her work, Kristeva differentiates between the semiotic and the symbolic modes of signification. The semiotic is associated with the pre-Oedipal, maternal, and bodily drives, characterized by rhythms and sounds that precede the structured language (symbolic) associated with the paternal law and social order. This distinction is crucial in her analysis of how meaning and subjectivity are constituted.
3. Subjectivity and Psychoanalysis: Kristeva integrates psychoanalytic theory into her analysis of text and culture. She focuses on the process of subject formation, exploring how the individual comes into being through language. Her concept of the “subject in process” or “subject on trial” emphasizes the ongoing and unfinished nature of becoming a subject, which contests the notion of a stable and coherent identity.
4. Abjection: One of Kristeva’s most influential concepts is that of “abjection,” which she explores in her work “Powers of Horror.” Abjection describes the human reaction to a threatened breakdown in meaning caused by the loss of the distinction between subject and object or between self and other. This concept is often invoked in discussing reactions to corporeal reality, bodily fluids, and the material dimension of being that disrupts identity and order.
5. Feminism and the Feminine: Although Kristeva does not consider herself a feminist in the traditional sense, her work has been hugely influential in feminist theory. She critiques the phallocentric order and explores the situation of women in patriarchal cultures. However, her views on the maternal body and its role in the pre-symbolic stage offer a nuanced understanding of “the feminine,” which has sparked debates within feminist circles.
6. The Novel and Narrative as Therapy: Kristeva also posits that the novel and other narrative forms can serve as forms of therapy, helping individuals to articulate their identity crises and renegotiate their subjectivities. Her analysis often demonstrates how literary texts achieve what psychoanalysis seeks to do: to articulate the inexpressible parts of human experience.
7. Ethics and Foreignness: In her more recent works, Kristeva has turned towards the themes of foreignness, the stranger, and hospitality. She explores the ethical responsibility towards the Other and the role of the foreigner in challenging the boundaries of identity and community.

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Analytical Philosophy

Preface: analytical philosophy concerns itself with symbolic formal logic, which ends up having a lot of crossover with mathematics. Indeed, late 19th and early 20th century logic was motivated by attempting to make logic as rigorous and axiomatic as math had become throughout the 19th century. As such, many of the people here will actually be mathematicians whose contributions might seem only tangential to philosophy. But, there is an old adage among mathematicians and analytical philosophers that every mathematician has to be half a philosopher and every philosopher has to be half a mathematician.

Another consequence of this mixture of math and philosophy is that a symbolic language has been invented for logic. Here I will give some definitions for a few of these symbols, since they will pop up here and there during this explication.

• ∀ is the universal quantifier. It can be read as “for all…”
  • ∀x can be read as “for all x” which means it is talking about all of the things that x can stand for
  • Sometimes parentheses are used instead, where (x) is the same as ∀x
  • If you see ∀xPx it means “for all x such that x is P”
• ∃ is the existential quantifier. It can be read as “there exists a…”
  • ∃x can be read as “there exists an x…”
  • ∃xPx can be read as “there exists an x such that x is P”
• → is the material implication. It’s basically the symbol for if-then statements, where x→y means “if x, then y”. Sometimes you will see ⊃ used instead of →
• ≡ means if and only if, which is sometimes written as “iff” and sometimes the symbols ⟷ or ⇔ are used. This means that A≡B can be read as “A if and only if B” and is true only if both A and B are true or if A and B are false.
• ¬ and ˜ are both used as a negation. If you see ¬P that can be read as “not P” (e.g., where if P meant “blue” then ¬P would mean “not blue”)
• ∧ and & are both used for the conjunction “and” so if you see A∧B that means “A and B”
• ∨ and + are both used for the disjunction “or” so if you see A∨B that means “A or B or both” (since it is the inclusive or, it means “either A or B or both A and B”)
• { } brackets are used to denote a set. So if you see {a, b, c} that means the set that contains the elements a, b, and c.
• ∈ means element of. If you see a∈M it means that “a is an element of the set M”
• ∪ means the union of two or more sets. If you se A∪B that means “the union of sets A and B” which means all of the elements in both A and B as well as any elements that overlap.
• ∩ means the intersection of two or more sets. If you see A∩B that means “the intersection of sets A and B” which means only the elements of A and B that overlap.
• ⊆ is the subset symbol. If you see A⊆B that means “A is a subset of B” Alternatively, ⊄ means not a subset.
• Ø is the empty set such that Ø = {}
• \ the backslash is used for a set difference. So if you see A\B it means that set of all members of A that are not members of B
  • If you see A△B that means the set of all elements that are only a member of A or of B. This is called the symmetric difference.
• × is the Cartesian product, which takes all the ordered pairs of two sets. So if you see A×B it means a set whose members are pairs composed of every member of A paired with a member of B. For instance, if we have A = {a, b, c} and B = {d, e, f} then A×B = {(a,d), (a,e), (a,f), (b,d), (b,e), (b,f), (c,d), (c,e), (c,f)} where (_,_) are ordered pairs.
• P(A) is the power set of A, which is usually written with a fancy letter P. A power set is just every combination of elements in a set, including the empty set and the entire set itself. For instance, if A = {a, b, c} then P(A) = {Ø, a, b, c, {a, b}, {a, c}, {b, c}, {a, b, c}}

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Augustus De Morgan (June 27, 1806 C.E. – March 18, 1871 C.E.): British mathematician and logician

1. De Morgan’s Laws:
   • The negation of a disjunction is the conjunction of the negations
     • not-(A or B) = not-A and not-B
   • The negation of a conjunction is the disjunction of the negations
     • not-(A and B) = not-A or not-B
2. Upgrade to Aristotle: the introduction of quantification (differentiate between most and some)
   1. (copied from Wikipedia): The followers of Aristotle say that from two particular propositions such as Some M’s are A’s, and Some M’s are B’s nothing follows of necessity about the relation of the A’s and B’s. But they go further and say in order that any relation about the A’s and B’s may follow of necessity, the middle term must be taken universally in one of the premises. De Morgan pointed out that from Most M’s are A’s and Most M’s are B’s it follows of necessity that some A’s are B’s and he formulated the numerically definite syllogism which puts this principle in exact quantitative form. Suppose that the number of the M’s is m, of the M’s that are A’s is a, and of the M’s that are B’s is b; then there are at least ( a + b − m ) A’s that are B’s. Suppose that the number of souls on board a steamer was 1000, that 500 were in the saloon, and 700 were lost. It follows of necessity, that at least 700 + 500 – 1000, that is, 200, saloon passengers were lost. This single principle suffices to prove the validity of all the Aristotelian moods. It is therefore a fundamental principle in necessary reasoning. 
3. Mathematical Induction
   • Proof by Induction: First step is to prove the base case for n = 0 without assuming any knowledge of other cases. The second step is the induction step, proving that if the statement holds for any given case n = k, then it must also hold for the next case n = k + 1

George Boole (November 2, 1815 C.E. – December 8, 1864 C.E.): English mathematician, philosopher, and logician. There is dispute about whether Boole or De Morgan is the originator of the predicate quantifier.

1. In his book Mathematical Analysis of Logic, Boole wanted to make logic more mathematical. To do this he showed how algebraic properties like the distributive and commutative properties apply to classes.
   • xy = the intersection of class x and class y
   • Distributive: x(u + v) = the intersection of x with the disjoint classes u and v
   • Commutative: xy = yx meaning that the intersection order doesn’t matter
   • Idempotent law: ${}^{}x$

• From this we know that x = ${}^{}$${}^{}$${}^{}$${}^{}$${}^{}$
• We can then use Boole’s algebra with integer coefficients and x,y = {0,1}
• It’s from this that Boolean algebra can be derived. There is a lot to go into with it that will take this far down the rabbit hole. I recommend the Stanford Encyclopedia entry on Boole if you want more detail. The take-home message, however, is that this helped generalize logic and make it more algorithmic.

• Generalization of Aristotelian Logic: augmenting Aristotle’s four types of categorical propositions by allowing the subject and/or predicate to be of the form not-$X$.

• Conversion by Limitation: All $X$ is $Y$, therefore Some $Y$ is $X$ – Boole found Aristotelian classification defective since it didn’t treat contraries, such as not-$X$, the same footing as named classes $X,Y,Z$, etc. For example, Boole converted No $X$ is $Y$ into All $Y$ is not-$X$, and All X is Y into All not-Y is not-X

• In his other book, The Laws of Thought, Boole set out to correct and clarify some of the mistakes from the previous book while also bringing in concepts from probability theory.

Karl Weierstrass (October 31, 1815 C.E. – February 19, 1897 C.E.): German mathematician often cited as the “father of modern analysis”

1. Pioneer in the mathematical field of real analysis, coming up with the δ-ε method of showing continuity (a requirement for being able to do algebra on a function is that it is continuous).
   • The function f(x) is continuous at x = x₀ if for all ε > 0 there exists a δ > 0 such that for every x in the domain of f(x): if |x – x₀| < δ then |f(x) – f(x₀)| < ε
2. You can get a sense of Weierstrass’s contribution by how many theorems contain his name.
3. One way that this is important for philosophy is when it comes to things like functional analysis, which is where set theory and topology are given more mathematical rigor. Sets in particular take on great importance in analytical philosophy.

Richard Dedekind (October 6, 1831 C.E. – February 12, 1916 C.E.): German mathematician who made important contributions to number theory, abstract algebra, and the axiomatic foundations of arithmetic

1. He gave a rigorous definition of rational and irrational real numbers. The former is any real number that can be expressed as the division of two integers {n,m} of the form n/m. The latter cannot be expressed this way. Examples of irrational numbers are π, e, √2, and so on (there are uncountably infinite irrational numbers).

Giuseppe Peano (August 27, 1858 C.E. – April 20, 1932 C.E.): Italian mathematician

Georg Cantor (March 3, 1845 C.E. – January 6, 1918 C.E.):

Gottlob Frege (November 8, 1848 C.E. – July 26, 1925 C.E.): while others above made great leaps forward in logic from the Aristotelian form in which it had stagnated until the 19th century, it was Frege who really brought it all together and kicked off the logic renaissance of the 20th century. Frege had wanted to make logic as rigorous as mathematics, and while he is largely considered to have failed in that regard, he mage great leaps forward in how logic is done, as well as motivating the largely formal, symbolic way that logic is now done.

1. Propositions as Functions: Frege thought of propositions as a kind of function. A proposition is something of the form “S is P” where S is a subject, P a predicate, and “is” the copula joining them. Frege came up with the idea of sort of emptying S out and making the subject position a variable so that it was more like “X is P” where X can take on multiple “values” (subjects) for the same predicate, where the output is either “True” or “False”. By this, it means that “X is P” is sort of like a mathematical function f(x) where x can range over multiple values (e.g., all the real numbers) such that when x = a then f(x) = f(a) and when x = b then f(x) = f(b). In the same way, the “X is P” can range over every possible subject, and then output “True” when it is actually the case that the subject being substituted in for X is, in fact, P, and “False” when the subject is not P.
   1. Some examples of “X is P” where P = blue
      1. X = the sky – “[the sky] is blue = True”
      2. X = a tree – “[a tree] is blue = False”
      3. X = a horse – “[a tree] is blue = False”
      4. X = a sapphire – “[a sapphire] is blue = True”
      5. And so on for every object in existence
2. Sense and Reference (“On Sense and Reference”, Frege 1892): a problem arose for Frege: when we assign a specific subject to our proposition, how do we know that what we are referring to is the same thing? For instance, when I say the name Socrates when I make the proposition “Socrates is a Philosopher from ancient Greece” how do I know that the name “Socrates” refers to the same thing for anyone who reads the proposition? Or, more famously, when I talk about the morning star (phosphorous) and the evening star (hesperus), to what am I referring? It turns out that the actual object to which I refer is the same in both cases, namely the planet Venus. So, according to Frege, the reference for Socrates is the actual man who had lived; for both phosphorous and hesperus, they both refer to the actual planet Venus.
   • There still seems to be something missing, though. For one person, the name Socrates means something, but for another it has a different meaning. Same with the morning star and the evening star. They both have a different sense. And this is what Frege meant by sense. To simplify things, it essentially means the sort of subjective concept of the thing being referred to. The morning star has a different subjective meaning than the evening star, even if they both refer to the same thing, objectively speaking.
3. Extension (“On Concept and Object“, Frege 1892 and The Foundations of Arithmetic, Frege 1884): these are the objects that a concept points to, i.e., the referents of a concept. All of the subjects, which are real things in the word, that make “X is P” true, are the extension of that set. Thus, the elements of a set can be fined as the objects that make “X is P = True” be the case.
   • Frege also had the notion of intensionality, though without calling it that. Intensionality is the meaning or definition of a concept. Frege said that the predicate in “X is P” pointed to the concept. What he meant by this wasn’t 100% clear, since he often talked about the concept having an objective existence (even with his doctrine of sense, he refused to think of this as being subjective, even though I described it that way above as a simplification – Frege had a real aversion of psychologizing things).

Bertrand Russell (May 18, 1872 C.E. – February 2, 1970 C.E.): British philosopher and activist. While most of what I will discuss here has to do with Russell’s philosophy, it’s important to point out that much of his time was devoted to activism, whether his pacifism, his atheism, or his nuclear disarmament stance. Indeed, a lot of accounts of Russell’s contributions to analytical philosophy focus on his very early career, particularly his work with Alfred North Whitehead on Principia Mathematica (PM), his 1905 paper On Denoting, and his 1908 paper Mathematical Logic as Based on the Theory of Types. I will focus mainly on these three things (for now, though I will add more in future edits of this post).

1. Russell’s Paradox: if Bertrand Russell is famous for anything besides his atheism (that seems to be how the internet likes to remember him), it’s for his eponymous paradox. This has to do with a letter he sent to Gottlob Frege, who had been working on the foundations of arithmetic, came up with his “basic laws“, of which “basic law V” had a paradox that Russell spotted.
   • Basic Law V (source): the extension of the concept $F$ is identical to the extension of the concept $G$ if and only if all and only the objects that fall under $F$ fall under $G$ (i.e., if and only if the concepts $F$ and $G$ are materially equivalent). In more modern guise, Frege’s Basic Law V asserts that the set of $F$s is identical to the set of $G$s if and only if $F$ and $G$are materially equivalent: $\{x\mid Fx\}=\{y\mid Gy\}\equiv \forall z(Fz\equiv Gz)$
   • The Law of Extensions asserts that an object is a member of the extension of a concept if and only if it falls under that concept: $\forall F\forall x(x\in ϵF\equiv Fx)$
   • Principle of Extensionality asserts that if two extensions have the same members, they are identical: $Extension\left(x\right)\&Extension\left(y\right)\to \left[\forall z\right(z\in x\equiv z\in y)\to x=y]$
   • The Paradox: being an x that is the extension of some concept which x doesn’t fall under
     • The paradox can be stated in plain English: the set of all sets that don’t contain themselves. If the set doesn’t contain itself, then it is a set that doesn’t contain itself, and therefore must be contained within itself, but then it cannot be contained within itself. Or, the popularized version that Russell used: a barber that own shaves those who do not shave themselves.
2. Principia Mathematica: this is a dense set of books filled with lots of fancy notation. Few people have probably ever read through the entire thing. Thankfully, Russell put out a much shortened version later on that condenses everything: Introduction to Mathematical Philosophy. It essentially attempts to ground arithmetic in axiomatic set theory (or, more precisely, Russell’s Type Theory).
3. Logical Atomism (adapted from here): philosophy is “logical atomism”, both metaphysically and methodologically. The former means that the world consists of a many independently existing things that have internal qualities and external relations. All truths are dependent on atomic facts, which are simples with qualities or multiple simples standing in relation to one another. The methodology is that of analysis, where we define complex notions using the simples. Through this we could come to a language that only has words for these simples, their properties, and their relations.
4. On Denoting: again, as a sort of response to Frege, Russell put forth his theory of denotation. This is a theory of how to fix a reference (i.e., how to determine that X in the proposition “X is P” is actually referring to the correct and universally agreed upon subject). It basically says that the reference is fixed to a description, where the name of something is a sort of placeholder for a complete description of that thing. For instance, when someone says the name “Alexander the Great” they are using a shorthand for “the Macedonian son of Philip II and Olympias, born in 356 B.C.E., tutored by Aristotle, reigned as king of Macedon from 336 B.C.E. until his death in 323 B.C.E., conqueror of Persia and Egypt, etc.”
   1. Descriptions vs. Names: Russell distinguishes between what he calls proper names and definite descriptions. According to him, many terms that appear to be names are actually disguised descriptions. For example, “Aristotle” can be understood as “the student of Plato and teacher of Alexander,” which is a description rather than a straightforward name.
   2. Denoting Phrases: Russell focuses on phrases that denote something, which he categorizes as:
      • Definite descriptions: Phrases that attempt to pinpoint one specific object, such as “the current King of France.”
      • Indefinite descriptions: Phrases that do not refer to a unique object but rather to any one of a class, such as “a man.”
   3. Existence and Non-existence: One of the significant issues Russell addresses is how language can meaningfully refer to non-existent objects without leading to contradictions or false implications of existence. For example, “The current King of France is bald” should not imply that there is a current King of France.
   4. Theory of Descriptions: Russell’s solution involves analyzing sentences containing descriptions into their constituent parts. He suggests that every sentence with a description can be reformulated to avoid direct reference to non-existent entities. The statement “The current King of France is bald” is analyzed as:
      • There is an entity x such that x is currently King of France.
      • For every entity y, if y is currently King of France, then y is identical to x.
      • x is bald.
   5. This formulation shows that the original statement is false because the first condition fails – there is no such entity x.
   6. Scope of Descriptions: Russell’s analysis introduces the idea of the scope of a description, which helps determine the logical form of sentences. The scope of a quantifier (like “there exists”) affects whether the description implies the existence of the object described or merely posits it hypothetically for the sake of argument.
5. Type Theory: to try getting around his own eponymous paradox, Russell came up with his theory of types, which essentially tried to make a hierarchy of sets wherein a set can only contain elements that are below it within the hierarchy. The base of this hierarchy would be specific, concrete objects. Those objects can then be grouped together into a set. We then have a second order of things, which are sets composed of specific, concrete objects as their elements. These sets cannot contain each other, i.e., the set of all chairs cannot contain the set of all possums as an element. But, these sets can then be grouped together into a higher third order set. For instance, the set of all squirrels and the set of all leopards can be grouped together into the higher order set of all mammals. This can continue on ad infinitum. This makes it so that a set cannot contain itself (since a set would be at the same level as itself and therefore could not contain itself).
   1. Types and Hierarchies: Russell’s Type Theory proposes that entities should be organized into a hierarchy of types to prevent certain kinds of self-referential paradoxes. The basic idea is that entities of a certain type can only be acted upon by entities from a higher type, not by entities of the same type or lower. This hierarchy prevents problematic constructions, such as a set being a member of itself.
   2. Orders of Types: In Type Theory, objects are of the “first type,” sets of objects are of the “second type,” sets of sets of objects are of the “third type,” and so on. Functions also have types. A function of a set of a particular type must be of a higher type than the set it acts upon. This structuring ensures that no set can contain itself (since it would have to be of a higher type than itself) and no function can take itself as an argument.
   3. Simple and Ramified Theory of Types: Russell initially developed the simple theory of types, which prevented entities from belonging to sets of the same or lower type. However, to address more sophisticated logical issues, including those involving properties and propositions about sets, he introduced the ramified theory of types. This version includes not only “orders” of types based on the complexity of their construction (as in objects, sets of objects, sets of sets of objects, etc.) but also levels that distinguish between propositions depending on whether they quantifiably assert properties of sets or properties of the properties of sets.
   4. Avoidance of Paradoxes: The main motivation behind Type Theory was to avoid paradoxes like Russell’s Paradox. By imposing strict rules about how sets can be formed and how elements and sets can interact based on their types, Russell aimed to provide a foundation for mathematics and logic that was free from contradictions.
   5. Impact on Mathematics and Logic: While Type Theory was successful in resolving certain paradoxes in set theory and logic, it introduced a level of complexity and verbosity that some found cumbersome. This led to alternative set theories, like Zermelo-Fraenkel set theory, which became more widely adopted partly due to their relative simplicity and intuitive axioms.
   6. Influence on Computer Science: Despite its limitations in pure mathematics, Type Theory has had a substantial influence on fields outside of traditional logic, particularly in computer science. It has informed the development of type systems in programming languages, which help to ensure that operations are performed on data of the correct type, thereby preventing many common programming errors.
   7. Russell’s theory of types is largely thought to be a failure, at least as far as being rigorous. Some of the axioms (like the axiom of reducibility) are disputed, and it is sometimes charged with being arbitrary (why should it be that sets at a certain “level” can’t contain other sets at that level? This is just taken axiomatically and goes unjustified).

Ernst Zermelo (July 27, 1871 C.E. – May 21, 1953 C.E.): German logician and mathematician. With Abraham Fraenkel he helped come up with Zermelo–Fraenkel set theory. Abraham Fraenkel (February 17, 1891 C.E. – October 15, 1965 C.E.): German-born Israeli mathematician. With Ernst Zermelo he helped come up with Zermelo–Fraenkel set theory. I am putting these two together because it is going to be their work on set theory that I discuss here. I will lay out the axioms of Zermelo-Fraenkel set theory, from which all the rest of set theory (and perhaps even arithmetic and all the rest of math) can be derived.

• Axiom of extensionality: Two sets are equal (are the same set) if they have the same elements.
  • ∀x∀y[∀z(z∈x⇔z∈y)→x=y]
• Axiom of regularity: Every non-empty set x contains a member y such that x and y are disjoint sets.
  • ∀x[∃a(a∈x)→∃y(y∈x∧¬∃z(z∈y∧z∈x))]
• Axiom schema of specification: Given any set A, there is a set B (a subset of A) such that, given any set x, x is a member of B if and only if x is a member of A and φ holds for x
  • φ is a formula, which is essentially any string of symbols that you can ask the question “is φ true?”
  • let ϕ be any formula in the language of ZFC with all free variables among x , z ,w₁ , … ,w_n (y is not free in ϕ). Then:
    • ∀z∀w₁∀w₂∀w₃…∀w_n∃y∀x[x∈y⇔((x∈z)∧ϕ)]
• Axiom of pairing: If x and y are sets, then there exists a set which contains x and y as elements.
  • ∀x∀y∃z((x∈z)∧(y∈z))
• Axiom of union: For any set of sets F there is a set A containing every element that is a member of some member of F.
  • For example, the set of sets F = {{1, 2}, {2, 3}, {3, 4}} then A is a set that contains only the elements of those “internal” sets such that A = {1, 2, 3, 4}
  • ∪F = {x∈A : ∃Y(x∈Y∧Y∈F}
• Axiom schema of replacement: The image of a set under any definable function will also fall inside a set.
  • For example, if we have a function on the real numbers F(x) = 2x, then the image F(x) at 2 [which is in the original set] is F(2) = 2(2) = 4 [which is in the image of the set]. There will be a corresponding image for each member of the real numbers, and those images are also a set.
  • ∀A∀w₁∀w₂∀w₃…∀w_n[∀x(x∈A→∃!yϕ)→∃B∀x(x∈A→∃y(y∈B∧ϕ))]
• Axiom of infinity: In words, there is a set I (the set which is postulated to be infinite), such that the empty set is in I, and such that whenever any x is a member of I, the set formed by taking the union of x with its singleton {x} is also a member of I. Such a set is sometimes called an inductive set.
  • This is essentially the successor notation:
    • 0 = Ø = {}
    • 1 = Ø∪{Ø} = {}∪{Ø} = {{}}
    • 2 = 1∪{1} = {Ø}∪{1} = {0, 1} = {{}, {{}}}
    • And so on up to infinity
• Axiom of power set: For any set x, there is a set y that contains every subset of x.
  • ∀x∃y∀z[z⊆x→z∈y]
• Well-ordering theorem: For any set X, there is a binary relation R which well-orders X. This means R is a linear order on X such that every nonempty subset of X has a member which is minimal under R.
  • An example of a well-ordered set are the natural numbers, which are well ordered by the binary relation ≤
  • ∀X∃R(R well-orders X)

Rudolf Carnap (May 18, 1891 C.E. – September 14, 1970 C.E.): German philosopher best known for being an originator of what is known as logical positivism (sometimes logical empiricism) and being a prominent member of the so-called Vienna Circle.

1. Logical Positivism: the logical positivist movement was broadly concerned with making philosophy more scientific. This came with a strong skepticism of metaphysics, which the logical positivists thought was nonsense. This was because such metaphysical claims could not be verified, where the logical positivists held strong to verificationism, which said that only statements that can be empirically verified (or are an analytic tautology) are meaningful. In Kantian terms, the logical positivists thought that only a priori analytical statements and a posteriori synthetic statements were meaningful, where the former are essentially tautologies meant to clarify language while the latter were empirical statements that could at least in principle be verified.
   • A priori analytical statements are those that do not need to be empirically verified because it is expressing a definition, or the predicate is contained within the subject, or the subject and predicate are synonyms. For instance “bachelors are unmarried men” is essentially tautological, since the words “unmarried men” is synonymous with “bachelors” and so one could substitute it so that it says “bachelors are bachelors.”
   • A posteriori synthetic statements are propositions that have to be verified in order to determine if it is true. For instance “seawater has a salinity of between 31 g/kg and 38 g/kg” does not have the predicate “salinity between 31 g/kg and 38 g/kg” contained in the subject “seawater”. Instead, a person has to actually go out in the real world and discover this fact.
2. Conceptual Engineering: for Carnap, our concepts are not things that exist out in the real world, but are things that we make up about the world – they are voluntaristic. Since all we can know about the world is what can be empirically verified, and the existence of such concepts cannot be empirically verified, then they don’t actually exist, except as useful tools to help us do science. They are what Carnap called explications or rational reconstructions.
   • Frameworks: logical object languages can be engineered with rules of logical inference. These formal languages can be applied to the sciences, where empirical facts are used to interpret the purely syntactical formal symbols of the language. The formal language itself, however, is without any semantic interpretation on its own.
   • For Carnap’s discussion of this, see his The Logical Structure of the World and Pseudoproblems in Philosophy (often called the Aufbau, where aufbau is a German word often translated as construction) and The Logical Syntax of Language.
   • Principle of Tolerance: this is the idea that no formal, syntactical framework is intrinsically better than any other. The most we could say is that one is more useful for a specific purpose than another might be. This gets at Carnap’s distinction between internal and external questions, where the former are questions that can be asked within a framework and the latter are questions that can be asked about a framework (for instance, how useful is this framework for what we’re trying to do?). What one cannot ask, however, is whether the framework is “true” in some more metaphysical sense, i.e., whether the concepts used within the framework correspond to actually existing things out there in the real world (e.g., are “quantum fields” something that actually exist in some ontological sense?).
3. In future edits of this post I will discuss Carnap’s “On Inductive Logic“, Meaning and Necessity, and “Empiricism, Semantics, and Ontology“.

Alfred Tarski (January 14, 1901 C.E. – October 26, 1983 C.E.): Polish-American logician and mathematician. A prolific author best known for his work on model theory, metamathematics, and algebraic logic, he also contributed to abstract algebra, topology, geometry, measure theory, mathematical logic, set theory, and analytic philosophy.

1. Truth: in philosophy, one of the main things Tarski is known for is his investigation into the concept of truth in formal languages. His book The Concept of Truth in Formalized Languages (1935), and his papers “The Semantic Conception of Truth“ (1944) and “Turth and Proof” (1969) are his best known works on this problem.
2. Object Language and Metalanguage (source): when we talk about a language (with language being understood as a formal logic), the language we are using is the Metalanguage and the language we are talking about is the Object Language. We can call the former M and the latter L. The role of M, which can use notions from set theory, is to give definitions in L and to say whether a statement in L is true or not (by saying S “is true of L” where S is some sentence said in L). Anyone you can say in L also needs to be able to be said in M (M should contain a “copy” of L). The  definition of True in M has to be in terms of the other expressions in M, dependent on the syntax, set theory, and the notions expressible in L, but not semantic notions such as ‘denote’ or ‘mean’ (unless the object language happened to contain these notions).
   • Formal Correctness: a sentence is formally correct if it has the form “for all x, True(x) if and only if ϕ(x)” and True never occurs in ϕ
   • Material Adequacy: a sentence in L is true if “ϕ(S) if and only if ψ” which can essentially be translated as “[sentence S] if and only if (sentence S)” where the square brakets is saying the sentence, but in the object language, where the parantheses is saying the sentence in the metalanguage. For example, “[the sky is blue] if and only if (the sky is blue)” which is kind of like saying “the sentence [the sky is blue] is true if and only if it is actually the case that the sky is blue.”
3. Truth Definitions: Tarski gives four such definitions. One way would be to simply list every sentence in a language and label the true ones as true and the false ones as false. I will go through the other three in more detail.
   • Satisfaction: when something satisfies a formula in the object language. This is a sort of Fregean view, where we can think of a formula “F” as a kind of function that we can input things into and have it give the output of either True (if x satisfies F) or False (if x failes to satisfy F). This satisfaction definition of truth allows it to remain purely syntactical, since actually putting in an object for “x” would make it semantical. And so we get the following (source):
     • The assignment a satisfies the formula ‘F and G’ if and only if a satisfies F and a satisfies G
     • The assignment a satisfies the formula ‘For all x, G’ if and only if for every individual i, if b is the assignment that assigns i to the variable x and is otherwise exactly like a, then b satisfies G
   • Compositionality: this is a semantic notion of truth, where the meanings of the words in a sentence are sufficient to determine the truth of the sentence.
   • Quantifier Elimination: Theorem. If the domain A [the set of all of the objects in the object language L] is infinite, then a sentence S of the [object] language L is correct in A if and only if S is deducible from [the set of true facts in the object language L] T and the sentences saying that the number of elements of A is not any finite number.
     • The kinds of “facts” included in T would be things like “‘x is the empty set’ (viz. x⊆ every class)” and “‘x is an atom’ (viz. x is not empty, but every subclass of x not equal to x is empty)”
     • The proof is a bit too long for our purposes, but you can read it here.

John von Neumann (December 28, 1903 C.E. – February 8, 1957 C.E.): Hungarian-American mathematician, physicist, computer scientist, engineer and polymath. He was the rare kind of genius who seems to have had a hand in just about everything in 20th century mathematics. Wikipedia lists the following: “Von Neumann made major contributions to many fields, including mathematics (foundations of mathematics, functional analysis, ergodic theory, group theory, lattice theory, representation theory, operator algebras, geometry, and numerical analysis), physics (quantum mechanics, hydrodynamics, and quantum statistical mechanics), economics (game theory and general equilibrium theory), computing (Von Neumann architecture, linear programming, numerical meteorology, scientific computing, self-replicating machines, stochastic computing), and statistics. He was a pioneer of the application of operator theory to quantum mechanics in the development of functional analysis, and a key figure in the development of game theory and the concepts of cellular automata, the universal constructor and the digital computer.” While there isn’t something I could point to as a direct contribution to philosophy from von Neumann, many of the areas in which he worked are extremely important to philosophy, and so he is worth mentioning just because of how much what he has accomplished influences philosophy.

Frank Ramsey (February 22, 1903 C.E. – January 19, 1930): British philosopher, mathematician, and economist. Personal friend of Ludwig Wittgenstein. His withering criticisms of both Wittgenstein’s Tractatus Logico-Philosophicus and Russell & Whitehead’s Principia Mathematica led Wittgenstein to largely abandon his work (leading to his later work, the Philosophical Investigations) and showed how Russell’s Theory of Types ran into too many problems to remain workable.

1. You can read Ramsey’s most influential papers in this PDF of the book edited by D. H. Mellor.
2. “Universals”: Ramsey points out that the subject-predicate style of logic is merely a holdover from language and isn’t necessarily the logical way that propositions must be structured. For instance, the sentences “Socrates is wise” and “wisdom is a characteristic of Socrates” both express the same thought, but in the former Socrates is the subject and wisdom is the predicate while in the latter wisdom is the subject and Socrates is the predicate. Which one is subject and which one is predicate is therefore not a logical distinction, but merely a linguistic one that depends on which thing (Socrates or wisdom) we want to emphasize.
3. “Facts and Propositions”:

Kurt Gödel (April 28, 1906 C.E. – January 14, 1978 C.E.): obviously most known for his incompleteness theorems. You can read the paper here, but it’s fairly technical. The video below does a great job of explaining both the motivation behind the incompleteness theorems and explaining what it means.

Ludwig Wittgenstein (April 26, 1889 C.E. – April 29, 1951 C.E.): both the continental philosophers (postmodernists, Marxists, critical theorists) and the analytical philosophers like to claim Wittgenstein as their own. He may or may not have started it, but he codified the linguistic turn taken by both. Since the publication of the Tractatus Logico-Philosophicus in 1921/1922, both the continental and analytical philosophers have examined the role of language in philosophy, the former concerned with how language shapes people and society, the latter with how it applies to logic and epistemology.

1. Tractatus Logico-Philosophicus
   1. Picture Theory of Language: Wittgenstein proposed that the structure of language mirrors the structure of reality. In this view, language consists of propositions that function as pictures of the world, capturing the world’s logical structure through their own logical form.
   2. Limits of Language and Thought: A central thesis of the “Tractatus” is that the limits of language are the limits of the world. This idea leads to his famous dictum, “Whereof one cannot speak, thereof one must be silent.” According to Wittgenstein, most philosophical problems arise from misunderstandings about the logic of language.
   3. Logical Atomism: Wittgenstein introduced the notion of logical atomism, where the world consists of a set of facts that are logically independent of each other. The role of language is to represent these facts through propositions that are logically structured to reflect reality.
   4. Mysticism and Ethics: The “Tractatus” concludes with remarks on the mystical, suggesting that the most important aspects of human life—ethical, aesthetic, and mystical—are beyond what can be captured by language. They are, in a sense, transcendental.
2. Philosophical Investigations
   1. Language Games: Moving away from the idea that language merely depicts reality, Wittgenstein introduced the concept of “language games,” which shows how the meaning of words is shaped by their use within specific forms of life and social activities. Language, in this view, is inherently tied to action and is a form of life itself.
   2. Rule-following and Public Language: Wittgenstein explored how the meaning of language is grounded in social practices. Understanding and meaning are not merely mental states but are embedded in the communal activities and the rules that govern them. He famously critiqued private language, arguing that language inherently requires public criteria to function.
   3. Philosophy as Therapy: In his later work, Wittgenstein saw the role of philosophy not as solving metaphysical problems but as clarifying thoughts to dissolve philosophical confusion. He described his approach as a form of therapy, aiming to show the fly the way out of the fly-bottle—a metaphor for freeing ourselves from the traps of linguistic and conceptual confusion.
   4. Continuity and Change: Although Wittgenstein’s later work significantly departs from his earlier views, some scholars see a degree of continuity in his persistent focus on the importance of logical structure in understanding language, thought, and reality.

W. V. O. Quine (June 25, 1908 C.E. – December 25, 2000 C.E.): American philosopher and logician in the analytic tradition, recognized as “one of the most influential philosophers of the twentieth century”

1. Rejection of the Analytic-Synthetic Distinction: In his essay “Two Dogmas of Empiricism” Quine criticizes the distinction between analytic truths (statements true by virtue of meanings and independent of facts) and synthetic truths (statements whose truth depends on how the world is). He argues that no clear boundary exists between these two, suggesting that all knowledge is contingent on the empirical content of language and experience.
   1. Analytic-Synthetic Distinction:The first dogma Quine addresses is the analytic-synthetic distinction. Analytic statements are those considered true by virtue of meanings and independent of facts (e.g., “All bachelors are unmarried”), while synthetic statements are those whose truth depends on the way the world is (e.g., “There is a cat on the mat”). Logical empiricists like Rudolf Carnap believed this distinction was clear and fundamental to understanding logical truths versus empirical truths.Quine challenges this distinction on several grounds:
      • He argues that no clear boundary exists between analytic truths, which are supposedly grounded in meanings alone, and synthetic truths, which are contingent on empirical facts. He suggests that meanings themselves are not fixed and are malleable depending on the empirical and theoretical context.
      • He further contends that our understanding of meanings and confirmation of empirical facts are interdependent processes, both influenced by our overall network of beliefs and experiences, or what he later refers to as the “web of belief.”
   2. The second dogma, reductionism, is the view that each meaningful statement can be translated into the language of sensory experiences. This is essentially the logical positivist’s verification principle, where the meaning of a statement is its method of empirical verification.Quine criticizes reductionism by arguing that:
      • Our statements about the external world face the tribunal of sense experience not individually but only as a collective body. This idea, which Quine describes through the metaphor of the web of belief, suggests that our knowledge, hypotheses, and theories work together to make predictions. When predictions fail, it may require adjustments in various interconnected parts of our web of belief, not necessarily or solely in the specific hypotheses tested.
      • It’s impractical to verify each statement individually because empirical testing involves and affects multiple parts of our theoretical framework simultaneously.
2. Holism: Quine proposes a holistic view of knowledge and language, suggesting that our beliefs and statements about the world form an interconnected web. According to his “web of belief,” changes in one area of our system of knowledge can affect other areas – our beliefs, including those about the external world, do not stand alone; they are part of a holistic network. This means that our beliefs interconnect with and support one another in a system-like manner.. This interconnectedness means that empirical data do not confirm or refute individual hypotheses in isolation but rather the theoretical framework as a whole.
   1. Non-foundationalism: Quine rejects the notion that there are “foundational” beliefs that are directly justified by sensory experiences or self-evident truths. Instead, all beliefs, including those about basic sensory experiences, gain their justification from how well they fit within the overall web of beliefs. This approach contrasts sharply with the foundationalism found in traditional empiricism, where knowledge builds upon indubitable truths derived from experience.
   2. Coherence and Consistency: The coherence and consistency of the web are crucial for the justification of any belief within it. When new experiences or data do not conform to the existing web, adjustments are made not only to those beliefs directly affected by the new information but potentially to any related beliefs that help maintain the overall consistency of the network.
   3. Centrality and Peripherality: Some beliefs in the web hold a more central role, being deeply embedded within the network and thus less susceptible to revision. These central beliefs often include the laws of logic, principles of mathematics, and deep-seated scientific theories. More peripheral beliefs are easier to revise without necessitating widespread changes across the network.
   4. Empirical Content and Underdetermination: While empirical content is crucial for adjusting the web, Quine emphasizes that observations alone underdetermine theory. That is, multiple theoretical frameworks can account for the same set of observations, and choices among theories are guided by criteria such as simplicity, elegance, and explanatory power, in addition to empirical adequacy.
      • Theory-Ladenness of Observation: Quine’s model implies that what we observe is always interpreted through the lens of our existing beliefs, suggesting that observations are theory-laden. This challenges the notion that we can have direct, theory-independent access to facts about the world.
      • Science: In science, the web of belief model suggests that revisions in scientific theories can have wide-ranging effects, influencing various interconnected hypotheses and theoretical commitments. This aligns with the view of science as a dynamic and evolving endeavor, where changes can reverberate through the entire system of knowledge.
      • Underdetermination and Choice: The underdetermination of theories by data means that scientific choice involves more than just empirical evidence. Philosophical, aesthetic, and pragmatic considerations play a significant role in theory selection.
3. Naturalized Epistemology: Quine advocates for naturalized epistemology, which suggests that epistemological questions should be approached in the same manner as questions in the natural sciences. Rather than seeking a foundational justification for scientific practices, Quine proposes that epistemology should focus on how humans actually derive understanding from observation, integrating philosophical studies with psychological and sociological approaches.
4. Indeterminacy of Translation: One of Quine’s famous theories is the indeterminacy of translation. He argues that radical translation (translating a language we know nothing about) demonstrates that there are multiple valid ways to interpret a speaker’s words, which implies that no unique meaning can be assigned to any given sentence. This leads to the conclusion that meaning is less about words and more about their role within the overall language and practices of the community.
5. Ontological Relativity: Following from his rejection of a strict distinction between analytic and synthetic statements, Quine develops the concept of ontological relativity. He posits that because there is no objective standpoint from which to understand the world, all observations are theory-laden. As a result, our commitments about what exists (our ontology) depend on the conceptual scheme through which we are making our observations.

Karl Popper (July 28, 1902 C.E. – September 17, 1994 C.E.): Austrian-British philosopher, academic and social commentator. One of the 20th century’s most influential philosophers of science, Popper is known for his rejection of the classical inductivist views on the scientific method in favor of empirical falsification.

1. Falsifiability: Popper’s most notable contribution is his criterion of falsifiability to demarcate science from non-science. According to Popper, a theory is scientific only if it is refutable by a conceivable event. A genuine scientific theory, unlike a pseudoscientific theory, must be testable and capable of being proven false. This stands in contrast to the traditional view of science as building on a foundation of verified truths.
2. Critique of Induction: Popper was critical of the traditional inductive reasoning approach in science, which involves forming generalizations based on a series of observations. Instead, he proposed that science advances through a process of conjectures and refutations. Scientists propose hypotheses that are then rigorously tested, and these hypotheses are either falsified or corroborated (but never conclusively verified). This ongoing process helps refine our understanding and expand knowledge.
3. Open Society and Democracy: In his political philosophy, particularly in “The Open Society and Its Enemies,” Popper defends democracy and open society, which he characterizes by a government that can be changed without violence, protection of individual rights, and a climate of cultural and ideological openness. He criticizes the totalitarianism found in the historicism of Plato, Hegel, and Marx, arguing that their deterministic and teleological views of history justify authoritarianism.
4. Objective Knowledge: In “Objective Knowledge,” Popper argues that knowledge should be considered objective not in the sense of being “subject-independent” but as being independent of anybody’s claim to know; it exists in the form of conjectural theories which are inter-subjectively testable. He introduces the concept of “three worlds”: the physical world, the mental world, and the world of objective contents of thought, including scientific theories and cultural artifacts.
5. Evolutionary Epistemology: Popper also contributed to epistemology with his theory of evolutionary epistemology, wherein he applies the principles of evolutionary biology to the growth of scientific knowledge. He suggests that the development of knowledge progresses through a process of problem-solving by trial and error, analogous to biological evolution.
6. Philosophy of History: Popper vehemently opposed the notion that history unfolds according to immutable laws, as argued by Marxists and other historicists. He believed that the course of human history is influenced by an indeterminate number of factors, including human decisions, making it unpredictable and contingent.

Donald Davidson (March 6, 1917 C.E. – August 30, 2003 C.E.): American philosopher who worked extensively in philosophy of mind, philosophy of language, and action theory.

1. Action and Intention: Davidson’s work on the philosophy of action emphasizes that actions are inherently rational and that any action an agent performs can be described as rational when viewed under the right light. He argued that reasons for actions should be seen as causes, thus making the case for a causal theory of action. This means that actions are not just caused by beliefs and desires, they are rationalized by them, bridging the gap between reason and causality.
2. Anomalous Monism: Perhaps one of Davidson’s most famous contributions is his theory of anomalous monism, which concerns the mind-body relationship. According to this view, every mental event is identical with a physical event, yet mental properties cannot be reduced to physical properties. This position asserts that while mental states are caused by physical states, there are no strict laws connecting the mental to the physical, due to the fundamentally different natures of their respective properties.
   1. Monism (Physical Monism): All events are physical events. There are no separate mental and physical substances; everything that happens is part of the physical world, including mental events.
   2. Token Identity: Every mental event is identical to some physical event. This principle, known as token identity, asserts that each particular instance of a mental event (token) is the same as a particular instance of a physical event.
   3. Anomalism of the Mental: There are no strict laws (laws that are both necessary and sufficient) that govern relationships between mental events and physical events, owing to the inherent differences in their properties. Mental events are described by psychological laws which are inherently imprecise, making them “anomalous” relative to the strict laws of physical science.
   4. Rejection of Reductive Materialism: While Davidson’s anomalous monism is a form of materialism (asserting that everything is physical), it rejects reductive materialism which holds that mental states and properties can be reduced to physical states and properties. Davidson argues that mental events are indeed physical but possess properties that cannot be fully explained by the laws of physics due to their normative and intensional character.
   5. Causal Interaction: Davidson maintains that mental events are causally related to physical events. This position allows him to argue that mental states (like beliefs and desires) can affect physical states (like brain states and behaviors), which supports the common-sense view that what we think and feel can cause us to act in certain ways.
   6. Normative Nature of the Mental: One of the reasons mental events are anomalous, according to Davidson, is because they operate under different, normative rules (rules about what ought to be the case, such as rational, moral, or aesthetic norms) that don’t neatly align with the descriptive laws of physics.
   7. Holism of the Mental: Davidson’s view also implies a holism about the mental: the idea that what a particular mental state means depends crucially on its network of relationships with other mental states. Therefore, mental states cannot be isolated or reduced to brain states without losing essential aspects of their identity.
3. Principle of Charity: In his work on philosophy of language, Davidson introduced the principle of charity, a methodological principle that suggests when interpreting another speaker, one must assume that the speaker’s beliefs and statements are logical and, by and large, true. This principle is crucial for understanding and attributing meaning, especially in translating languages and formulating semantic theories.
4. Theory of Meaning: Davidson also developed a significant theory of meaning based on the concept of truth. He argued that knowing the meaning of a sentence is knowing under what conditions the sentence is true—thereby linking meaning to truth conditions. This idea was foundational to his semantic view that to learn the language is to learn the conditions under which sentences in the language hold true.
5. Triangulation: Davidson introduced the concept of triangulation to explain how learning and communicating language depend on interpersonal interactions. The process involves two people interacting with each other and with the world, which helps them to identify and correct errors in their understanding of both language and the shared environment.
6. Holism: Davidson advocated for a form of semantic holism, where understanding a single word or sentence requires understanding the language as a whole. This stems from his view that beliefs, meanings, and intentions are interdependent, such that understanding any of these elements involves understanding how they relate within the entire system of beliefs and language.

John Rawls (February 21, 1921 C.E. – November 24, 2002 C.E.): American moral and political philosopher in the liberal tradition.

1. Theory of Justice: Rawls is best known for his “Theory of Justice” which introduced the concepts of ‘justice as fairness.’ Rawls’s theory primarily addresses the basic structure of society—the major political, social, and economic institutions that distribute fundamental rights and duties, and determine the division of advantages from social cooperation. By prioritizing the rights and well-being of the least advantaged, Rawls shifts the focus from maximizing utility or pursuing economic efficiency to ensuring fairness and equality. Rawls posits two principles of justice that he believes any fair and just society should follow:
   1. First Principle (Equal Liberty Principle): Each person is to have an equal right to the most extensive basic liberty compatible with a similar liberty for others. These liberties include freedom of speech, the right to vote, liberty of conscience, and other fundamental rights.
   2. Second Principle (Difference Principle and Fair Equality of Opportunity): Social and economic inequalities are to be arranged so that they are both (a) to the greatest benefit of the least advantaged (Difference Principle), and (b) attached to offices and positions open to all under conditions of fair equality of opportunity.
      • Fair Equality of Opportunity: Positions of authority and offices of power must be open to everyone under conditions of fair equality of opportunity, not merely formal legal equality. This means that individuals should have equal opportunities to qualify for positions, and such opportunities should not be determined by their social class or wealth.
      • Difference Principle: Social and economic inequalities are to be arranged so that they are both reasonably expected to be to everyone’s advantage and attached to positions open to all under conditions of fair equality of opportunity. Essentially, the difference principle permits inequalities only if they benefit the least advantaged members of society.
2. Original Position and Veil of Ignorance: To determine these principles, Rawls introduces the hypothetical original position in which individuals choose the principles that will govern a society but do so behind a “veil of ignorance.” This veil prevents them from knowing their place in society, class position, or social status, and even their fortune in the distribution of natural assets and abilities, their intelligence, strength, and the like. This ensures that no one is advantaged or disadvantaged in the choice of principles by the outcome of natural chance or social circumstance.
3. Reflective Equilibrium: Rawls proposes the method of reflective equilibrium as a way for individuals to arrive at just principles. This involves adjusting one’s principles to better match one’s considered judgments on particular cases and vice versa until one reaches consistency or equilibrium between principles and judgments.
4. Political Liberalism: published in 1993, Rawls extends and revises some of the concepts introduced in his earlier work, “A Theory of Justice.” The book addresses the problem of how a stable and just society can exist despite the diversity of conflicting reasonable comprehensive doctrines (religious, philosophical, and moral) that free institutions allow and even encourage.
   1. Public Reason: In his later work, “Political Liberalism,” Rawls extends his theory to address the question of how a stable and just society can exist with the diversity of incompatible and irreconcilable doctrines. He introduces the idea of public reason, arguing that political decisions should be justifiable to all citizens using reasoning that all can accept, rather than by appealing to individual conceptions of the good. Rawls argues that in a pluralistic society, citizens must reason together about political matters in terms the public can accept. This implies using reason that is shared within the public political forum rather than reasoning based on the premises of one’s own comprehensive doctrine.
   2. Overlapping Consensus: Rawls suggests that a stable, liberal democracy is possible if there is an overlapping consensus among the diverse doctrines that exist in society. Overlapping consensus involves different comprehensive doctrines endorsing the political conception of justice for their own reasons. This consensus is key to political stability because it is based on agreement on political values, even if for different reasons, rather than a temporary truce that could dissolve due to shifting balances of power. This consensus does not mean agreement on all philosophical, moral, or religious questions, but rather on political conceptions of justice that can underpin the society’s basic structure.
   3. Political Conception of Justice: Rawls distinguishes between a political conception of justice and comprehensive doctrines. He emphasizes that his theory of justice (“justice as fairness”) is a political conception, designed specifically for the basic structure of society and not meant as a comprehensive moral philosophy. This political conception can be supported by different reasonable comprehensive doctrines, allowing it to serve as a common ground for the basis of societal agreement.
   4. Justice as Fairness: Rawls revisits the two principles of justice outlined in “A Theory of Justice.” He reiterates that the first principle (equal basic liberties) has priority over the second (social and economic inequalities arranged for the benefit of the least advantaged, and positions and offices of authority open to all). However, the emphasis in “Political Liberalism” is on how these principles can be a focus of an overlapping consensus among different reasonable comprehensive doctrines in a pluralistic society.
   5. Reasonable Pluralism: Rawls discusses reasonable pluralism as an inevitable outcome of democratic institutions that recognize human rights and encourage freedom of thought and conscience. He argues that such pluralism should be seen not just as a permanent condition of democracy but also as a beneficial one that enhances the moral and political culture.

Hilary Putnam (July 31, 1926 C.E. – March 13, 2016 C.E.): American philosopher, mathematician, and computer scientist, and a major figure in analytic philosophy in the second half of the 20th century. He made significant contributions to philosophy of mind, philosophy of language, philosophy of mathematics, and philosophy of science.

Wilfrid Sellars (May 20, 1912 C.E. – July 2, 1989 C.E.): American philosopher and prominent developer of critical realism.

John Searle (July 31, 1932 C.E. – Present): American philosopher widely noted for contributions to the philosophy of language, philosophy of mind, and social philosophy.

Thomas Nagel (July 4, 1937 C.E. – Present): American philosopher working in legal philosophy, political philosophy, and ethics.

Ned Block (1942 C.E. – Present): American philosopher working in philosophy of mind who has made important contributions to the understanding of consciousness and the philosophy of cognitive science.

Saul Kripke (November 13, 1940 C.E. – Present): American philosopher and logician in the analytic tradition. He has been a central figure in a number of fields related to mathematical logic, modal logic, philosophy of language, philosophy of mathematics, metaphysics, epistemology, and recursion theory.

1. You can read a lot of his papers here: http://saulkripkecenter.org/index.php/papers-and-abstracts/

Alvin Plantinga (November 15, 1932 C.E. – Present): American analytic philosopher who works primarily in the fields of philosophy of religion, epistemology, and logic. Much of his work is in Christian apologetics, using logic and analytical philosophy to defend theism in general and Christianity in particular.

1. You can read a lot of his papers here: https://andrewmbailey.com/ap/

Peter van Inwagen (September 21, 1942 C.E. – Present): American analytic philosopher working in areas of metaphysics, philosophy of religion, and philosophy of action.

1. You can read a lot of his papers here: https://andrewmbailey.com/pvi/

Daniel Dennett (March 28, 1942 C.E. – Present): American philosopher, writer, and cognitive scientist whose research centers on the philosophy of mind, philosophy of science, and philosophy of biology, particularly as those fields relate to evolutionary biology and cognitive science.

Douglas Hofstadter (February 15, 1945 C.E. – Present): American scholar of cognitive science, physics, and comparative literature whose research includes concepts such as the sense of self in relation to the external world, consciousness, analogy-making, artistic creation, literary translation, and discovery in mathematics and physics.

David Chalmers (April 20, 1966 C.E. – Present): Australian philosopher and cognitive scientist specializing in the areas of philosophy of mind and philosophy of language.

1. I’ve discussed his book Reality+: Virtual Worlds and the Problems of Philosophy in my review and his book The Conscious Mind: In Search of a Fundamental Theory in this post.

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Islamist Thinkers

Muhammad ibn Abd al-Wahhab (1703 C.E. – June 22, 1792 C.E.): Islamic scholar, religious leader, reformer, activist, and theologian from Najd in central Arabia. He is the founder of the Sunni fundamentalist Wahhabi movement.

1. Tawhid (Monotheism): The central aspect of Ibn Abd al-Wahhab’s teaching is a rigorous assertion of the concept of Tawhid, or the oneness of God. He stressed an uncompromising monotheism and was vehemently opposed to all forms of practices that, in his view, associated partners with God (shirk). This included the veneration of saints, visiting tombs and shrines, and any ritual practices that involved intermediaries between God and man.
2. Rejection of Bid‘ah (Innovation): Ibn Abd al-Wahhab was strict in his insistence on following only the Quran and the Hadith, rejecting any innovations (bid‘ah) introduced in religious practices after the time of the earliest Muslims. He argued that all such innovations led to polytheism and were therefore a form of apostasy.
3. Simplification and Purification: His approach was to simplify the practice of Islam, removing what he considered to be unwarranted accretions that had crept into Islamic practices over the centuries. He sought to purify Islam by returning to what he and his followers considered the pure practices of the Prophet Muhammad and his companions.
4. Legal and Social Reform: Ibn Abd al-Wahhab also called for the application of Sharia (Islamic law) in its entirety, emphasizing the Hudud (fixed punishments in Islamic law). His teachings include strict adherence to Islamic law as a means of governance, affecting legal, social, and personal conduct.
5. Jihad: He revived the idea of jihad, which he interpreted primarily as a struggle against internal decay in Islam as well as a defense against external threats to the Muslim ummah (community). This was part of his broader vision of reforming society and ensuring a community that lived in accordance with Islamic principles.

Jamal al-Din al-Afghani (1838 C.E. – March 9, 1897 C.E.): Afghan political activist and Islamic ideologist

Muhammad Rasheed Rida (September 23, 1865 C.E. – August 22, 1935 C.E.): Lebanese Islamic scholar, reformer, theologian and revivalist

Hassan al-Banna (October 14, 1906 C.E. – assassinated February 12, 1949 C.E.): Egyptian schoolteacher and imam. Best known for founding the Muslim Brotherhood.

Sayyid Qutb (October 9, 1906 C.E. – August 29, 1966 C.E.): Egyptian author, educator, Islamic scholar, theorist, revolutionary, poet, and a leading member of the Egyptian Muslim Brotherhood. Qutb’s writings on Islamic ideology, including his theory of Jahiliyyah and his advocacy for a Quranic-based governance, have had a profound and lasting impact on contemporary Islamic thought, particularly within Islamist movements. His works are often seen as foundational texts for modern Islamic extremism, though his influence also permeates more mainstream Islamic political thought. Qutb’s philosophy represents a radical interpretation of Islam that seeks to confront and overturn the existing socio-political order to establish an Islamic theocracy.

1. Critique of Jahiliyyah: Qutb introduced the concept of Jahiliyyah, traditionally understood as the pre-Islamic period of ignorance, and applied it to modern societies, including so-called Muslim societies. He argued that any society failing to adhere strictly to Sharia (Islamic law) or that governed by man-made laws was in a state of Jahiliyyah, akin to the pre-Islamic ignorance. This included most contemporary Muslim societies, which he saw as corrupted by Western values and secularism.
2. Sovereignty of God (Hakimiyyah): Central to Qutb’s thought is the idea that sovereignty belongs to God alone (Hakimiyyah). He vehemently opposed secular governments and the concept of popular sovereignty, insisting that human governments replace God’s rule when they enact laws not based on Sharia. For Qutb, true freedom and liberation come from adherence to divine law, not from human-made political systems.
3. Social Justice and Islamic Economics: Qutb emphasized the role of Islam in providing social justice. He critiqued capitalism and socialism for their materialism and argued that only an Islamic system, which includes zakat (almsgiving) and prohibits interest (riba), could achieve true social justice and equity.
4. Revolutionary Vanguard: Influenced by Leninist strategy, Qutb believed that most Muslims had strayed from true Islam, necessitating a vanguard to lead a revolutionary struggle against Jahili societies. This group would spearhead the establishment of an Islamic state governed solely by Sharia, using both education and, if necessary, force to achieve their goals.
5. Universal Islam: Qutb envisioned Islam as a universal and revolutionary ideology, not just a religion but a complete system that governs all aspects of life—political, personal, economic, and social. He believed in the duty of Muslims to engage in a perpetual struggle (Jihad) to enforce God’s sovereignty on earth, convert humanity to Islam, and abolish all forms of Jahiliyyah.
6. Radicalism and Legacy: Qutb’s ideas, especially those articulated in works like “Milestones” and his extensive Quranic commentary “In the Shade of the Quran,” have been highly influential but also controversial. His advocacy for an Islamic state and his justification of violence in achieving this goal have inspired various Islamist and jihadist movements around the world, making him a central figure in discussions of radical Islam.

Abul A’la Maududi (September 25, 1903 C.E. – September 22, 1979 C.E.): Indian Islamic scholar, Islamist ideologue, Muslim philosopher, jurist, historian, and journalist

Mohammed Omar Mujahid (1960 C.E. – April 23, 2013 C.E.): Afghan religious scholar, partisan fighter and political leader. Often called just Mullah Omar

1. Founder of the Taliban and served as its first leader
2. Founded the Islamic Emirate of Afghanistan in 1996

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Political, Economic, and Sociological Theorists

Max Weber (April 21, 1864 C.E. – June 14, 1920 C.E.): German sociologist, historian, jurist, and political economist regarded as among the most important theorists of the development of modern Western society. Husband of Marianne Weber.

1. Rationalization and Modernity: One of Weber’s central themes is the process of rationalization, which he saw as a defining characteristic of Western modernity. He argued that modern societies are characterized by a move towards increasingly rational forms of economic, legal, and administrative organization. This process involves the application of technical efficiency, calculability, predictability, and control to all spheres of life.
2. Authority and Domination: Weber’s sociology of authority is best expressed in his tripartite classification of authority into traditional, charismatic, and legal-rational types. Traditional authority is based on long-standing customs, charismatic authority on the personal qualities and leadership of an individual, and legal-rational authority on a system of abstract rules (typified by modern bureaucracies). Weber explored how different authority systems operate and sustain themselves, and how they transition from one form to another.
3. The Protestant Ethic and the Spirit of Capitalism: Perhaps Weber’s most famous work, this book explores the relationship between the ethics of ascetic Protestantism and the emergence of modern capitalism. Weber argues that the Protestant work ethic, with its emphasis on discipline and a worldly calling, was a major force in the development of capitalism in the West. This connection was a prime example of Weber’s broader interest in how ideas and values shape economic behavior.
4. Methodological Individualism: Weber emphasized understanding social action from the viewpoint of individuals. He introduced the concept of “Verstehen” (understanding or interpretative understanding) as a methodological approach in social sciences, which involves empathetically understanding individual motives and the meanings individuals attach to their actions.
5. Economic Sociology: Weber’s analysis extended to the economic sphere, where he differed from Karl Marx by attributing as much influence to religious and cultural factors as to economic ones in the development of economic systems. His comprehensive studies in economic sociology examined the ways in which social and cultural factors influence economic activities.
6. The Sociology of Religion: Weber extensively studied various world religions, including Christianity, Judaism, Islam, Hinduism, and Buddhism. His work examined how religious ideas and communities shaped economic behaviors, legal institutions, and political systems. His comparative studies of religion highlight the diverse ways that religion can influence societal development.
7. Iron Cage of Bureaucracy: Weber described the increasing rationalization of the modern world as leading to an “iron cage,” where individual creativity and freedom become trapped by an impersonal bureaucracy, rigid routines, and an emphasis on efficiency that can lead to a sense of disenchantment.

Marianne Weber (August 2, 1870 C.E. – March 12, 1954 C.E.): German sociologist, women’s rights activist and the wife of Max Weber. Her intellectual pursuits focused on the conditions of women in society, the historical development of family structures, and the interplay between gender and power.

1. Feminist Sociology: Marianne Weber is best known for her feminist critiques and analyses. She explored how societal structures—legal, political, and economic—were patriarchal and systematically disadvantaged women. Her work provided a detailed examination of the ways in which laws and social norms restricted women’s legal rights and access to economic opportunities.
2. Marriage and Law: One of her most influential works, “Wife and Mother in the Development of Law,” provided an extensive historical analysis of the evolution of family law and its impacts on women’s roles and statuses in society. She argued that marriage laws often subjugated women by limiting their legal capacities and economic independence. Weber advocated for reforms that would grant women greater autonomy within marriage and society.
3. Women’s Suffrage and Activism: Marianne Weber was actively involved in the women’s suffrage movement in Germany. She believed that political participation was crucial for advancing women’s rights and argued that access to education and participation in public life were essential for achieving gender equality. Her activism was not limited to theoretical discourse; she also participated in various women’s organizations and efforts to reform marriage and education laws.
4. Gender and Authority: Weber analyzed the relationship between gender and authority both in private and public spheres. She discussed how patriarchal structures were perpetuated through cultural norms and how these structures could be resisted or reformed through legal and social changes. Her focus extended to the dynamics of authority within the family, viewing the family as a microcosm of broader societal power relations.
5. Ethics and Individuality: Weber placed great emphasis on the development of individuality and ethical responsibility. She believed that both men and women should be able to develop as individuals, unrestricted by rigid gender roles. This perspective was integral to her arguments for women’s education and professional engagement.

Georg Simmel (March 1, 1858 C.E. – September 28, 1918): German sociologist, philosopher, and critic. Simmel was influential in the field of sociology.

Émile Durkheim (April 15, 1858 C.E. – November 15, 1917 C.E.): French sociologist often considered one of the principal founders of modern sociology. His work established the framework for studies on the structure and function of society and its institutions. Durkheim’s major contributions revolve around the concept of social solidarity, the role of social institutions, and the societal causes and effects of religion and morality.

1. Social Facts: Durkheim introduced the concept of “social facts” to denote aspects of social life that shape individual behavior. He defined social facts as ways of acting, thinking, and feeling that are external to the individual and endowed with a power of coercion, by which they control him. These include laws, values, customs, religious beliefs, and norms that exist independent of individual desires and extend beyond personal or subjective interpretations.
2. Collective Conscience: Durkheim theorized in “The Division of Labor in Society” that society is glued together by a common consciousness or “collective conscience” that encompasses shared beliefs and sentiments. This collective conscience is stronger in more primitive societies (“mechanical solidarity”) where individuality is less pronounced, and people perform similar tasks. In contrast, in more advanced, industrial societies (“organic solidarity”), social cohesion derives from the interdependence of individuals who have specialized roles and functions.
3. Division of Labor: In his study of the division of labor in society, Durkheim argued that it is not just an economic phenomenon but a social mechanism that fosters social cohesion. He posited that as societies become more complex, the division of labor helps maintain social order by ensuring that individuals depend on each other for the fulfillment of their needs.
4. Anomie: Durkheim used the term “anomie” to describe a state of normlessness, where fading social norms fail to regulate individual behavior, often due to rapid social change or crisis. Anomie results in social instability and can lead to increased suicide and crime rates. His study of suicide was pioneering in its methodological approach, linking individual actions to broader social currents.
5. Religion and Society: In his seminal work, “The Elementary Forms of the Religious Life,” Durkheim explores religion as fundamentally a social phenomenon. Religion, for Durkheim, is an expression of social cohesion; rituals and beliefs are ways in which society reaffirms its collective unity. He argued that the concepts of the sacred and profane are essential classifications by which societies preserve and understand moral order.
6. Methodology: Durkheim is noted for his empirical approach to sociology. He insisted that sociologists should study social phenomena objectively, using the same scientific methods that are employed in the natural sciences, where possible. This approach helped to establish sociology as a distinct academic discipline.

Ferdinand Tönnies (July 26, 1855 C.E. – April 9, 1936 C.E.): German sociologist, economist, and philosopher, best known for his foundational work in sociological theory, particularly through his distinction between “Gemeinschaft” (community) and “Gesellschaft” (society). These concepts form the core of his work, helping to differentiate between two types of social groupings and their respective implications for social bonds and personal interactions.

1. Gemeinschaft and Gesellschaft: Tönnies introduced these terms in his 1887 book “Gemeinschaft und Gesellschaft,” which has been influential in sociology and social philosophy. “Gemeinschaft” refers to social groupings based on feelings of togetherness and mutual bonds, which are often observed in traditional and rural settings. These relationships are typically personal, direct, and based on kinship and neighborhood, encompassing a sense of shared history and moral obligation. In contrast, “Gesellschaft” describes associations in which relationships are more impersonal, indirect, and contractual. These are based on rational agreements and serve individual ends, typical of urban, industrial settings.
2. Natural Will and Rational Will: Tönnies associated Gemeinschaft with “natural will” (Wesenwille), where human relationships are governed by organic or spontaneously arising bonds. Here, the individual’s actions are heavily influenced by traditions and customs. Conversely, Gesellschaft is associated with “rational will” (Kürwille), where relationships are based on deliberate and strategic planning, reflecting individual goals and the dominance of personal interests over communal interests.
3. Transition from Gemeinschaft to Gesellschaft: Tönnies was particularly interested in the transition from Gemeinschaft to Gesellschaft, which he saw as a characteristic of modernizing societies. He believed that as societies develop and modernize, the social bonds shift from communal relationships rooted in family and local community to societal relationships driven by economic and political interests. This shift mirrors broader changes in the economic base, from agrarian to industrial, impacting social structures and individual identities.
4. Critique of Modernity: Similar to other classical theorists like Durkheim and Weber, Tönnies was critical of the process of modernization. He was concerned that the rise of Gesellschaft could lead to alienation, a loss of personal connections, and a decline in traditional values. His work reflects a nostalgic element for the loss of close-knit communities, although he also recognized the inevitability and rational benefits of societal development.

Frédéric Bastiat (June 30, 1801 C.E. – December 24, 1850 C.E.): French economist, writer and a prominent member of the French Liberal School.

Ludwig von Mises (September 29, 1881 C.E. – October 10, 1973 C.E.): Austrian School economist, historian, logician, and sociologist.

John Maynard Keynes (June 5, 1883 C.E. – April 21, 1946 C.E.): British economist

Friedrich Hayek (May 8, 1899 C.E. – March 23, 1992 C.E.): Austrian economist, legal theorist, and philosopher.

Milton Friedman (July 31, 1912 C.E. – November 16, 2006 C.E.): American economist and statistician who received the 1976 Nobel Memorial Prize in Economic Sciences for his research on consumption analysis, monetary history and theory and the complexity of stabilization policy.

Joseph Schumpeter (February 8, 1883 C.E. – January 8, 1950 C.E.): Austrian-born political economist.

Ayn Rand (February 2, 1905 C.E. – March 6, 1982 C.E.): Alice O’Connor, better known by her pen name Ayn Rand, was a Russian-born American writer and philosopher. She is known for her fiction and for developing a philosophical system she named Objectivism.

1. Objectivism: Rand named her philosophical system “Objectivism,” which asserts that reality exists independently of consciousness, that human beings have direct contact with reality through sense perception, and that one can attain objective knowledge from perception through the process of concept formation and inductive logic.
2. Rational Self-Interest: Central to Objectivism is the idea of rational self-interest, which holds that the moral purpose of one’s life is the pursuit of one’s own happiness or self-interest. Rand argued that rational self-interest and morality are not only compatible but fundamentally linked. This principle opposes ethical altruism, the view that moral virtue consists in selflessly serving the interests of others.
3. Individualism and Capitalism: Rand staunchly advocated for individual rights and freedoms, asserting that the individual is sovereign over their own life and actions. She believed that capitalism, the only economic system that she argued respects individual rights, should operate in a completely laissez-faire mode, free from government intervention. For Rand, capitalism facilitates a natural order where individuals can pursue their own interests in harmony with the common good, driven by the rational pursuit of long-term goals.
4. Ethics of Ayn Rand: Rand’s ethics emphasize achieving one’s own happiness as life’s ethical purpose. Virtues such as rationality, productivity, and pride are central to her ethical system, each serving one’s self-interest. She contrasts this with traditional ethical views that she believes demand the sacrifice of the individual to the group, which she condemns.
5. Politics: Politically, Rand was an advocate for a minimal state limited to the functions of police to protect against force, the military to protect against foreign aggression, and the courts to settle disputes under objective laws. She was critical of any form of collectivism or statism, which she saw as coercive and antithetical to individual freedom.
6. Aesthetics: In aesthetics, Rand held that art serves a deeply human need by concretizing an artist’s abstract values into a perceptible form that can be intellectually and emotionally experienced by others. She believed that the goal of art is to present not an exact replica of reality but an idealized version, showing life “as it could be and should be.”

Robert Nozick (November 16, 1938 C.E. – January 23, 2002 C.E.): American philosopher.

1. Minimal State: Nozick’s central political thesis is the advocacy for a minimal state, limited to the narrow functions of protection against force, theft, fraud, enforcement of contracts, and so on. He argues that any more extensive state will violate individuals’ rights not to be forced to do certain things, and that the state should not use its coercive powers to achieve more than these core functions.
2. Entitlement Theory: Nozick introduces the entitlement theory of justice, which consists of three main principles:
   • Justice in acquisition – This principle deals with the initial acquisition of holdings. It is concerned with how people first come to own common resources before they are owned or if they are unowned.
   • Justice in transfer – This principle explains how one person can acquire holdings from another, including voluntary exchange and gifts.
   • Rectification of injustice – If the first two principles are violated, the third principle comes into play, rectifying past injustices that occurred in acquisitions and transfers of holdings.
3. Against Distributive Justice: Nozick challenges the notion of distributive justice that requires some redistribution of economic goods to achieve fairness. He argues that if everyone is entitled to the holdings they possess under the entitlement theory, any distribution arising from everyone’s free exchanges is inherently just, and any state-enforced redistribution is unjust.
4. Side Constraints and Rights: Nozick posits that individuals have rights, which act as side constraints on actions. This means that to respect people’s rights, there are certain things we cannot do to them (such as stealing or assault), even if doing so might lead to some greater social good. These rights are considered inviolable.
5. Utopian Framework: In later parts of “Anarchy, State, and Utopia” Nozick sketches a framework for utopia, which allows individuals to form their own communities of mutual agreement. He envisages a meta-utopia of diverse, freely chosen communities where individuals can live according to their own visions of the good life, as long as they respect others’ rights to do the same. This framework is an expression of his vision of a minimal state that respects individual choices and fosters various forms of voluntary associations.
6. Philosophy of Mind: Apart from political philosophy, Nozick made significant contributions to the philosophy of mind and epistemology. In these areas, he explored complex issues about personal identity, consciousness, and knowledge, notably in his later book “Philosophical Explanations” (1981).

Leo Strauss (September 20, 1899 C.E. – October 18, 1973 C.E.): Jewish German-American political philosopher and classicist who specialized in classical political philosophy. Strauss’s teachings and writings have been highly influential, particularly in American political thought and policy circles, notably among neoconservative thinkers.

1. Critique of Modernity: Strauss was critical of modern philosophy and political ideologies, which he believed led to moral relativism and nihilism. He argued that the Enlightenment project, with its emphasis on reason and rejection of traditional values, had culminated in a loss of meaning and a crisis of the West. Strauss contended that modern thinkers, by abandoning classical and medieval philosophy’s pursuit of the “good life” in favor of a focus on individual freedom and technological control of nature, had undermined the philosophical foundations of a good society.
2. Return to Classical Philosophy: In response to what he saw as the failures of modernity, Strauss advocated a return to the study of classical texts of Plato, Aristotle, and other ancient philosophers. He believed these texts offered a richer, more complex understanding of human nature, politics, and ethics that could help address the challenges posed by modern life. Strauss emphasized the importance of understanding these texts as their authors intended, engaging deeply with their language, context, and esoteric meanings.
3. Philosophy as a Way of Life: Strauss viewed philosophy not merely as an academic discipline but as a way of life that demands rigorous questioning and sustained reflection on fundamental questions about human existence, society, and the nature of the good life. This perspective was influenced by his study of ancient philosophers for whom philosophy was an existential and ethical pursuit, not just theoretical.
4. Esoteric Writing: One of the most distinctive aspects of Strauss’s approach was his interest in the esoteric writing techniques of philosophers, especially those of antiquity. He argued that many philosophers wrote in a way that conveyed different meanings to different audiences; an exoteric, or outer, meaning for the general public, and an esoteric, or hidden, meaning intended only for the philosophically sophisticated readers. Strauss believed that recovering these hidden meanings required careful textual analysis and an understanding of the philosophical and historical context in which these works were written.
5. Political Philosophy and the “Right Order”: Strauss was deeply concerned with the nature of political order and the conditions that make a just and rational society possible. He explored various political regimes and their philosophical foundations, seeking to understand the enduring questions of political life, such as the relationship between morality and power, the role of religion in politics, and the nature of political justice.
6. Skepticism Towards Modern Liberalism: Strauss expressed deep skepticism about modernity and its foundational principles, particularly the Enlightenment’s emphasis on reason and individual rights, which he believed could lead to relativism and nihilism. This skepticism resonates with neoconservative critiques of modern liberal ideologies, which they often see as too permissive, leading to moral decay and a loss of traditional values.
7. Importance of Political Order and Stability: Strauss emphasized the importance of a stable political order and was wary of the destabilizing effects of radical individualism and moral relativism. He believed in the necessity of a strong state to maintain the social order, a view that aligns with the neoconservative emphasis on the need for authority, governance, and sometimes interventionist foreign policy to promote and protect democratic values globally.
8. Elitism in Governance: Strauss’s idea that not all truths are suitable for all persons and that there might be an elite who are better suited to understand complex truths can be seen as paralleling neoconservative views on governance. Neoconservatives often advocate for a form of governance guided by an informed elite who make decisions believed to be in the best interests of the nation, even if these decisions are not fully understood or supported by the general populace.
9. Role of Religion and Tradition: Strauss regarded religion and traditional morality as essential for political ethics and social cohesion. This perspective has influenced neoconservative views on the importance of religion and traditional values in American society, advocating policies that support religious institutions and moral teachings.
10. Defensive Foreign Policy: While Strauss himself did not delve deeply into specifics of foreign policy, his emphasis on the harsh realities of political life and the importance of maintaining a stable order influenced neoconservative strategic thinking. This is evident in the neoconservative approach to foreign policy, particularly the idea that American power can be a force for good in the world, advocating for the spread of democracy and intervention against regimes considered threats to global stability.

Carl Schmitt (July 11, 1888 C.E. – April 7, 1985 C.E.): German jurist, political theorist, and prominent member of the Nazi Party.

1. Concept of the Political: Schmitt is known for his definition of the political, which he argues in “The Concept of the Political” is characterized by the distinction between friend and enemy. This distinction is fundamental and existential, relating to the degree of intensity of an association or dissociation of people. According to Schmitt, the political is the most intense and extreme antagonism, and as such, it requires a clear delineation of who constitutes the ‘enemy’ as a matter of survival and identity.
2. Sovereignty: Schmitt’s notion of sovereignty is famously captured in his dictum: “Sovereign is he who decides on the exception.” This means that the sovereign does not just abide by the rule of law but actually decides whether the law can be suspended in a state of emergency. Schmitt argues that the sovereign’s ability to decide in times of crisis defines the essence of political authority and sovereignty, challenging legal positivism and constitutionalism.
3. Critique of Liberalism: Schmitt was a sharp critic of liberalism and parliamentary democracy, which he saw as problematic for their emphasis on discussion, negotiation, and compromise. According to Schmitt, these mechanisms are insufficient for achieving decisive political action, especially in times of crisis. He believed that liberal democracies failed to comprehend the nature of the political due to their focus on individualism and normative legal frameworks.
4. The State and the Exception: Related to his ideas on sovereignty, Schmitt places great emphasis on the state and its authority to transcend the rule of law in exceptional circumstances. He argues that the rule of law is contingent on the state’s ability to maintain order, and in a true state of emergency, the state must act beyond the law for the sake of its own preservation and the safety of its people.
5. Legality and Legitimacy: Schmitt distinguishes between legality (adherence to legal norms and procedures) and legitimacy (the foundational justification of a legal order). He critiques the liberal focus on legality as insufficient for establishing legitimate political authority, which must rest on a more fundamental acceptance and support from the populace.
6. Political Theology: In his work on political theology, Schmitt explores the parallels between theological and political concepts. He is interested in how theological motifs are secularized and how sovereignty and the state echo theological omnipotence.
7. Sovereignty and the Miraculous: Schmitt draws a direct parallel between the theological concept of God’s omnipotence and the political concept of sovereignty. He argues that just as God has the power to perform miracles, interrupting the natural order of the world, the sovereign has the power to decide on the state of exception, effectively suspending the law in times of crisis. This decision is akin to a miraculous intervention in the normal order of legal and political rules.
8. The Exception and Miracles: The state of exception, a central theme in Schmitt’s work, can be understood as a political miracle. This state is where the law is suspended by the sovereign in a crisis, which reflects the theological concept of a miracle — an extraordinary intervention by divine will. In both cases, the usual order is suspended by an absolute authority, whether divine or sovereign.
9. Secularization of Theological Concepts: Schmitt’s analysis extends beyond sovereignty to other political concepts. For example, he discusses how the idea of the covenant in political theory is derived from religious traditions. The secularization process according to Schmitt, involves translating these religious ideas into political terms, which retain their structural and functional characteristics but are expressed in secular language.
10. Legitimacy and the Divine Right of Kings: Another aspect of political theology is the legitimization of political authority through divine principles. Historically, the divine right of kings presented the monarch as God’s representative on Earth, mirroring the idea of divine authority. Schmitt sees the modern state’s authority as a secular transformation of this concept where the state assumes a role similar to that of divinity in ordering society.
11. Critique of Enlightenment Rationalism: Schmitt is critical of the Enlightenment’s attempt to purely rationalize political authority and social order. He argues that such rationalism often fails to account for the irrational dimensions of political life, such as the passions and animosities that define friend-enemy distinctions. Political theology acknowledges these undercurrents, grounding the state’s authority in something transcendent and ineffable, akin to religious awe.

Hannah Arendt (October 14, 1906 C.E. – December 4, 1975): Political philosopher, author, and Holocaust survivor. Her works explore themes of authority, democracy, totalitarianism, and the human condition, providing a nuanced understanding of political and social life. Arendt is best known for her works “The Human Condition,” “The Origins of Totalitarianism,” and “Eichmann in Jerusalem.”

1. The Human Condition: Arendt explores the fundamental activities of human life, which she categorizes as labor, work, and action. Labor corresponds to biological processes and necessities, work relates to the creation of an artificial world of things, and action is connected to political and public life, encompassing the capacity for freedom and beginning something new. Arendt emphasizes the importance of the public realm, where action takes place and where individuals express their freedom through speech and participation in communal affairs.
2. Totalitarianism: In “The Origins of Totalitarianism” Arendt examines the roots and characteristics of totalitarian regimes, focusing on Nazi Germany and Stalinist Soviet Union. She argues that totalitarianism is a novel form of government that seeks to dominate all aspects of life, utilizing terror and ideological propaganda to achieve total control. Arendt identifies loneliness and social atomization as conditions that allow totalitarian movements to gain power.
3. Banality of Evil: This concept arises from Arendt’s report on the trial of Adolf Eichmann, a key architect of the Holocaust. In “Eichmann in Jerusalem” she describes Eichmann not as a fanatic or a sociopath, but as an ordinary, rather unremarkable person who committed atrocities without any deep ideological conviction but rather an unthinking adherence to bureaucratic procedures. The “banality of evil” refers to the ordinary nature of most evil acts, which are performed by people who conform to the prevailing norms and rules, rather than by fanatics or sociopaths.
4. Natality and New Beginnings: Arendt places a strong emphasis on natality, the capacity to begin anew, which she considers the central characteristic of human action. In political terms, natality represents the potential for new beginnings, revolutionary change, and the unexpected in history, emphasizing human agency and creativity.
5. The Public Realm: Arendt’s concept of the public realm is a space where individuals come together to discuss, deliberate, and decide upon common affairs, ideally in a way that respects plurality and diversity. She distinguishes this from the private realm, which concerns the intimate, personal aspects of life. The vitality of the public realm is crucial for a healthy democracy.
6. Judgment and Thinking: Later in her life, Arendt became increasingly interested in the faculties of judgment and thinking. Informed by her studies on Kant and reactions to the Eichmann trial, she explored how the ability to think critically from multiple standpoints and to judge specific situations on their own merits is essential for moral and political responsibility.

Jürgen Habermas (June 18, 1929 C.E. – Present): German philosopher and sociologist in the tradition of critical theory and pragmatism. One of the foremost thinkers of the second generation of the Frankfurt School of critical theory. His extensive work covers a range of topics, including epistemology, ethics, democracy, and the public sphere. Habermas is best known for his theories on communicative action, the concept of the public sphere, and deliberative democracy.

1. Theory of Communicative Action: Habermas’s most influential contribution is his “Theory of Communicative Action.” He distinguishes between ‘strategic’ or ‘instrumental’ action, where individuals or groups act to achieve their own goals, and ‘communicative’ action, where individuals engage in dialogue aiming at mutual understanding and consensus. Habermas argues that communicative action is the foundation of a rational society because it fosters open, undistorted dialogue that can lead to consensus without coercion.
2. Public Sphere: In his work “The Structural Transformation of the Public Sphere,” Habermas explores the role of the public sphere in society—a domain of our social life where public opinion can be formed. He describes how individuals used to come together in coffee houses and salons to discuss and critique matters of public concern freely. Habermas contends that a healthy democracy requires a vibrant public sphere, but he also notes how it has been degraded by economic and governmental influences that manipulate public opinion.
   1. Habermas argues that in the late 19th and 20th centuries, the public sphere underwent structural transformations that led to its eventual decline. The growth of mass media and the culture industry, the increasing influence of corporate powers on public discourse, and the expansion of state welfare policies all contributed to blurring the lines between state and society, and between public and private sectors. These changes led to a refeudalization of the public sphere where media and political elites could manipulate public opinion, thereby diminishing the critical debate that characterized the earlier public sphere.
   2. A Realm of Discourse: The public sphere is characterized by its role as a forum for debate and discussion. It is distinct from the official spheres of government and the commercial sphere of the market. It ideally is a place for rational debate where individuals discuss matters of common interest without being subject to coercion.
   3.  Inclusivity and Equality: In its ideal form, the public sphere is an open space where all citizens can participate without discrimination. Each participant is considered equal, and no single voice should dominate the discourse. The communication should be characterized by rational argumentation, not by rhetoric or persuasion.
   4. Mediation Between Society and State: The public sphere acts as an intermediary between the state (with its power and administrative system) and the needs of society. It’s a space where societal problems are articulated, and the state can be held accountable.
   5. Influence on Democracy: Habermas links the health of the public sphere directly to the functioning of democracy. A vibrant public sphere contributes to a strong democracy because it fosters active participation from the public in governance.
3. Discourse Ethics: Habermas’s discourse ethics are grounded in the belief that all moral truths must be justifiable through rational discourse. He suggests that the legitimacy of norms and laws stems from the consent of all affected, who agree under conditions of free and rational discourse. This ethics model emphasizes the importance of communication and the role of reason in ethical matters.
4. Deliberative Democracy: Building on his theories of communicative action and the public sphere, Habermas develops the concept of deliberative democracy. This model of democracy emphasizes the need for rational discourse in the decision-making process, where participants debate and deliberate on policies to reach a rational consensus. For Habermas, democracy should be a system where law and policy are shaped by the participation of citizens in these rational discourses.
5. Colonization of the Lifeworld: Habermas discusses how systemic mechanisms of the market and state (which he calls ‘system worlds’) can encroach upon and dominate the ‘lifeworld’ (the realm of personal and cultural reproduction, individuality, and identity). He warns against the potential for economic and bureaucratic systems to subsume the lifeworld, impairing social and personal relations.
6. Modern Rationality: Across his works, Habermas addresses the concept of modernity and its rationalization processes, arguing that modern societies face the challenge of balancing systemic and lifeworld rationalities without allowing one to dominate the other.

Simone Weil (February 3, 1909 C.E. – August 24, 1943 C.E.): French philosopher, mystic, and political activist.

1. Attention and Compassion: One of Weil’s central philosophical concepts is the idea of “attention,” a form of deep, compassionate focus that enables one to truly perceive and respond to the suffering of others. For Weil, this form of attention is not only a way of seeing but a kind of loving regard, devoid of self-centered motivations, that affirms the dignity of every human being.
2. Affliction and Suffering: Weil placed great emphasis on the concept of “affliction” (malheur), a profound form of suffering that goes beyond physical or emotional pain to touch the very soul of the individual. She believed that affliction could strip away the illusions and attachments of the ego, opening the individual to the reality of the human condition and the presence of God.
3. The Need for Roots: In her book “The Need for Roots,” Weil argues for the importance of spiritual and cultural roots as essential to a person’s moral and social health. She critiqued the rootlessness and alienation brought about by modern industrial societies and proposed that true social reform must involve providing individuals with access to community, tradition, and spiritual nourishment.
4. Gravity and Grace: Weil’s thought is characterized by a dualism between “gravity” and “grace.” Gravity represents the force that pulls everything down towards selfishness, materialism, and egotism, while grace is the divine love that “raises” and enables selflessness and spiritual ascent. Her philosophy seeks a balance between these forces, advocating a detachment from personal desires and an orientation towards divine will.
5. Social Justice and Activism: Throughout her life, Weil was actively involved in political causes, advocating for workers’ rights, critiquing capitalism and fascism, and briefly fighting in the Spanish Civil War. Her political philosophy emphasized the need for social justice and the moral responsibility of individuals to oppose oppression and injustice.
6. Christian Mysticism and Religious Thought: Although Weil was raised in an agnostic Jewish family, she had a profound spiritual awakening influenced by Christian mysticism and the writings of various religious traditions. She never formally converted to Christianity, but her writings are imbued with themes of divine love, redemption, and sacrifice, and she often used Christian imagery and concepts to express her philosophical ideas.
7. Philosophy as a Way of Life: For Weil, philosophy was not merely an academic discipline but a way of life. Her work consistently reflects an integration of her intellectual pursuits with her personal experiences and her deep commitment to living out the ethical implications of her ideas.

Pierre Bourdieu (August 1, 1930 C.E. – January 23, 2002 C.E.): French sociologist and public intellectual. Bourdieu’s contributions to the sociology of education, the theory of sociology, and sociology of aesthetics have achieved wide influence in several related academic fields.

1. Habitus: One of Bourdieu’s most influential contributions is the concept of habitus. Habitus refers to the deeply ingrained habits, skills, and dispositions that we possess due to our life experiences. Bourdieu argues that habitus is shaped by our historical and social conditions and in turn shapes our perceptions, actions, and reactions. It is not fixed or permanent but evolves with new experiences and changing social contexts. Habitus plays a critical role in the reproduction of social structures. It helps to explain why social practices and divisions, such as class distinctions, persist over time. Since individuals from similar backgrounds develop similar dispositions, their practices tend to reinforce existing social structures. For example, the educational attainment and cultural tastes fostered by one’s family background can influence career opportunities and social mobility, thus perpetuating class structures.
   1. Structured Structures: Habitus is structured by one’s past and present circumstances, such as family upbringing, education, and cultural environment. These factors determine the attitudes, behaviors, and perceptions that individuals bring to their social interactions.
   2. Structuring Structures: At the same time, habitus also structures future practices and perceptions. It influences how individuals perceive the social world around them, how they act and react in various situations, and even how they perceive their own possibilities and potentials.
   3. Durability and Transposability: Habitus is durable, meaning it is ingrained over time and resistant to change. However, it is also transposable, allowing the dispositions it generates to be applied to new and different situations. This dual nature makes habitus both a product of past conditions and an ongoing set of schemes that shape current practices.
   4. Unconscious Nature: Much of the operation of habitus occurs at a subconscious level. People are generally not aware of how habitus shapes their perceptions and behaviors, which makes it a deeply ingrained part of who they are.
2. Capital: Bourdieu expands the notion of capital beyond its economic definition to include cultural, social, and symbolic capital.
   1. Cultural Capital can exist in three forms: in the embodied state, i.e., in the form of long-lasting dispositions of the mind and body; in the objectified state, in the form of cultural goods (pictures, books, dictionaries, instruments, machines, etc.); and in the institutionalized state, a form of objectification which must be set apart because it confers entirely original properties on the cultural capital which it is presumed to guarantee.
   2. Social Capital refers to resources based on group membership, relationships, networks of influence, and support.
   3. Symbolic Capital is prestige, honor, and attention associated with social positions.
3. Field: Bourdieu uses the concept of field to describe the various social arenas in which people operate. Each field has its own set of rules, roles, and relationships and can be thought of as a market of goods, services, or status. Fields are sites of struggle where individuals use their various forms of capital to advance their position. Fields are structured social spaces with their own rules, schemes of domination, and forms of authority. These fields are relatively autonomous social arenas where agents and institutions accumulate, exchange, and compete for various kinds of capital (economic, cultural, social, and symbolic). Examples of fields include the fields of art, education, law, medicine, politics, and religion. The concept of the field allows sociologists to analyze how various domains of social life function semi-independently but also intersect and influence each other. For example, the field of education is not just about learning but is also influenced by politics, economics, and other fields. Understanding a field involves exploring these interactions and the specific capitals that are at stake.
   1. Autonomy: Each field has a degree of autonomy and its own rules, which Bourdieu describes as the “nomos” of the field. This autonomy allows fields to operate according to their internal logics, independent of external influences, though fields can also interact and influence each other.
   2. Capital: Fields are arenas of struggle where agents compete over the specific forms of capital that are valued within that field. For example, in the academic field, the valued capitals might be intellectual recognition and academic qualifications, whereas in the field of business, economic capital is paramount.
   3. Habitus and Field Interaction: The habitus of individuals predisposes them to operate effectively within certain fields but not others. A person’s habitus affects how they perceive and react to the opportunities and constraints within a field, shaping their ability to accumulate capital and ascend in the field’s hierarchy.
   4. Power Structures: Fields are also spaces of hierarchical power structures based on the distribution of capital. Those who hold large amounts of capital within a field can exert significant influence over the field, including defining the rules of the game and the value of different types of capital.
   5. Field Dynamics: Fields are dynamic; they evolve as the positions within them change, as new forms of capital emerge, and as external conditions shift. Agents within a field both shape and are shaped by the field, contributing to its ongoing transformation.
4. Poles: Pierre Bourdieu’s conceptualization of the “autonomous pole” and the “heteronomous pole” within a field helps explain the internal dynamics and the tensions that exist in social fields, particularly in the fields of cultural production like art, literature, and academia. These concepts are central to understanding how different forces and interests shape the practices and products within these fields. In essence, Bourdieu’s concepts of the autonomous and heteronomous poles help elucidate the complex interplay between internal artistic or scholarly pursuits and external economic, political, and social influences.
   1. Autonomous Pole: The autonomous pole of a field represents the aspect where the activities and productions are governed by the norms, values, and interests intrinsic to the field itself. In other words, this pole is characterized by a high degree of independence from external economic and political influences. For instance, in the field of art, the autonomous pole would comprise artists and works that are driven by artistic innovation, creativity, and the specific standards of what constitutes “art” within that community. Works and agents in this pole are judged primarily by their peers — other artists and connoisseurs who value the internal standards of the art world above commercial success or broader social appeal.
   2. Heteronomous Pole: In contrast, the heteronomous pole is influenced significantly by external forces such as market demands, political power, and social capital. This pole is characterized by the intrusion of economic and political considerations into the field. In the art field, this would include artists and artworks that are shaped primarily by commercial success, marketability, or political utility. These works are often more accessible or appealing to the general public and are evaluated based on their popularity, sales, or ability to convey a political message.
   3. Tension and Conflict: The existence of these two poles within a field often leads to tension and conflict. Agents in the autonomous pole may view those in the heteronomous pole as sellouts or as compromising the field’s purity and integrity. Conversely, agents in the heteronomous pole might view those in the autonomous pole as elitist or disconnected from practical realities and broader social concerns.
   4. Cultural Production: These dynamics critically affect the nature of cultural production within the field. The tension between maintaining artistic integrity (autonomous) and achieving commercial success or political impact (heteronomous) shapes the kinds of cultural products that emerge.
   5. Field Evolution: The balance between these poles can shift over time due to changes in the field’s internal dynamics and external pressures. For example, increased marketization or political pressures can lead to a greater influence of the heteronomous pole.
   6. Indicator of Field Autonomy: The strength of the autonomous pole is often an indicator of a field’s overall autonomy. A strong autonomous pole suggests that the field is able to resist external pressures and maintain its own standards and criteria of evaluation.
5. Symbolic Violence: Bourdieu introduces the idea of symbolic violence, a type of non-physical violence manifested in the imposition of categories of thought and perception upon dominated social agents. Through symbolic violence, the dominant culture (or class) can impose its worldview as a universal norm, disguising the arbitrariness of its dominance.
6. Practice and Structure: Bourdieu’s theory seeks to transcend the dichotomies of objectivism and subjectivism, or structure and agency, by explaining how social structures determine individual practices and how individuals, through their practices, reproduce and sometimes change these structures. This dialectical relationship is mediated by habitus, which both shapes and is shaped by the evolving social field.

Alain Badiou (January 17, 1937 C.E. – Present): French philosopher, known for his ambitious and complex works that combine mathematics, political theory, and ontology. Badiou is a committed Platonist, arguing for the timeless relevance of Plato’s thought in addressing contemporary issues. His philosophy centers around several core concepts, including the Event, Truth, and the Subject, which he explores through a framework heavily influenced by set theory in mathematics.

1. Ontology and Mathematics: Badiou asserts that mathematics, specifically set theory, is the language of ontology, the study of being as being. His “Being and Event” posits that ontology can only be accurately described through mathematical terms. He suggests that reality consists of multiplicity of sets and subsets, rejecting the existence of any singular totality that encompasses the entire set.
2. The Event: Central to Badiou’s philosophy is the concept of the Event, which breaks with the continuity of being and has the power to transform structures and conditions. An Event is something that occurs unexpectedly relative to the situation in which it arises and cannot be explained or predicted based on the prior state of affairs. It marks a radical rupture with existing knowledge and structures. The Event fundamentally disrupts the normal state of affairs within any given situation. It is not predictable by the existing structure (or situation) and is not determined by the conditions that precede it. Events are rare and radical occurrences that break with the continuity and the rules governing the situations into which they erupt.
   1. Radical Novelty: An Event is marked by its radical novelty; it introduces something entirely new and unexpected that cannot be foreseen based on the existing knowledge or structures.
   2. Undecidability: From within a situation, an Event initially appears as undecidable. This means that within the framework of established knowledge, it is impossible to judge whether what has occurred truly constitutes an Event.
   3. Fidelity: Recognition of an Event requires a commitment, which Badiou calls “fidelity.” This is the process whereby individuals or groups decide to take the Event seriously and explore its consequences. Fidelity involves a sustained engagement with the truths that the Event makes possible.
   4. Universal Impact: Despite its specific occurrence, an Event has universal implications. It opens up new truths that are applicable universally, not just within the domain or situation where the Event initially took place.
   5. Truth and Subjectivity: For Badiou, Events are the foundational moments for the emergence of truths. He categorizes truths into four domains or “conditions”: science (mathematics), politics, art, and love. Each of these domains can experience Events that lead to the production of truths that were previously inaccessible or unimaginable. Following an Event, a “truth procedure” begins, which is the process through which the implications of the Event are explored and developed. This procedure involves the creation of a new “subject,” which, in Badiou’s theory, refers not to an individual but to a collective entity or a configuration of practices oriented around the fidelity to the Event.
   6. Examples:
      • In politics, the French Revolution represents an Event in that it introduced radically new ideas of citizenship and rights.
      • In science, he might cite the development of set theory by Georg Cantor as an Event that radically transformed the foundations of mathematics.
      • In art, a revolutionary style or movement that breaks dramatically with the past can be considered an Event.
3. Truth and Fidelity: For Badiou, a truth emerges from the Event and transcends established knowledge, offering a glimpse into the infinite. Truths are not pre-existing; they are produced through what he calls a ‘truth procedure.’ Once an Event occurs, individuals who recognize its significance can choose to remain faithful to this truth, a process that involves an ongoing commitment to the implications of the Event.
4. Subjectivity: In Badiou’s framework, a subject is not an individual but rather a process or a set of actions taken in fidelity to a truth. This view of the subject is tied to his concept of the Event; subjects are produced when individuals commit to engaging with the truth generated by an Event.
5. Politics and Maoism: Badiou’s political philosophy is influenced by his early commitment to Maoism and a staunch opposition to parliamentary democracy, which he views as conservative and ineffectual. He advocates for a politics of emancipation, aligning with his philosophy of radical change and innovation sparked by Events. His vision involves direct, revolutionary action that fundamentally transforms society.
6. Ethics: Unlike traditional approaches, Badiou’s notion of ethics is tied to his theory of truth and Events. He argues against a universal ethic, proposing instead that ethical actions are those that faithfully follow the implications of an Event. Thus, ethics is event-specific, rather than based on universal moral laws.
7. Love and Art: Badiou also applies his philosophical concepts to the domains of love and art. He considers love to be a form of truth procedure that transcends mere personal feelings and experiences, potentially leading to a transformational Event. In art, he views the creation and reception of artworks as potential Events that introduce new truths into the world.

Noam Chomsky (December 7, 1928 C.E. – Present): American linguist, philosopher, cognitive scientist, historical essayist, social critic, and political activist.

Thomas Sowell (June 30, 1930 C.E. – Present): American economist, historian, and social theorist.

Francis Fukuyama (October 27, 1952 – Present): Yoshihiro Francis Fukuyama is an American political scientist, political economist, and writer.

Slavoj Žižek (March 21, 1949 – Present): Slovenian philosopher, cultural critic, and psychoanalytic researcher.

1. Hegelian Dialectics and Lacanian Psychoanalysis: Žižek frequently utilizes Hegelian dialectics to analyze cultural and political phenomena, emphasizing the role of contradictions, negations, and reversals in historical development. He combines this with Lacanian psychoanalytical theory, particularly Lacan’s concepts of desire, the Real, and the Symbolic order, to explore how individuals and cultures construct their realities.
2. Ideology and The Real: A central theme in Žižek’s work is the exploration of ideology, which he understands in the Marxist sense as a set of beliefs that mask underlying contradictions. However, Žižek adds a psychoanalytical dimension by discussing how ideology not only masks reality but constitutes our very experience of it. The Real, in Lacanian terms, is what any ‘reality’ must suppress to organize itself; Žižek explores how moments of crisis reveal glimpses of the Real.
3. Subjectivity and Lack: Žižek often discusses the concept of the subject in terms of lack and desire. Drawing from Lacan, he argues that human subjects are fundamentally incomplete, driven by a desire for something always out of reach, and that this lack is constitutive of human subjectivity itself. This framework is used to analyze various cultural and political issues, where Žižek examines how different systems of power and control exploit this inherent lack.
4. Global Capitalism: Žižek is a vocal critic of global capitalism, which he sees as an all-encompassing system with profound effects on social relations and individual identities. He critiques the ways in which capitalism commodifies social life and culture, and he examines the paradoxes and contradictions that this commodification entails.
5. Revolutionary Potential: Reflecting his Marxist roots, Žižek frequently discusses the potential for revolutionary change. However, unlike traditional Marxists, Žižek emphasizes the need for a reevaluation of revolutionary theory and practice in light of global capitalism’s complexities. He is skeptical of simplistic solutions and often critiques leftist movements for failing to grasp the radical implications of their actions.
6. Pop Culture Analysis: One of Žižek’s distinctive approaches is his use of pop culture to explain complex philosophical and psychoanalytical ideas. He often analyzes films, books, and popular media to discuss philosophical concepts, demonstrating both how media reflects societal ideologies and how it can reveal fundamental truths about human nature and social organization.
7. Critique of Liberalism: Žižek is critical of contemporary political liberalism, which he sees as ultimately complicit with capitalism. He argues that liberal tolerance and multiculturalism often serve to mask underlying social conflicts and contradictions rather than resolving them.

Renata Salecl (January 9, 1962 C.E. – Present): Slovene philosopher, sociologist and legal theorist.

1. Paradox of Choice: One of Salecl’s central themes is the analysis of choice in contemporary society. In her book “The Tyranny of Choice” she argues that the abundance of choices in modern capitalist societies does not liberate individuals but rather increases anxiety and feelings of inadequacy. The emphasis on personal choice shifts responsibility for well-being onto individuals, often obscuring structural limitations and inequalities that constrain these choices.
2. Impact of Neoliberalism: Salecl frequently critiques the impact of neoliberal ideologies on social and individual behaviors. She examines how neoliberalism promotes a self-reliant individualism that can lead to competitive individualism, self-optimization, and a constant pursuit of efficiency, often at the cost of personal and communal well-being.
3. Use of Psychoanalysis: Like many in her intellectual circle, Salecl employs psychoanalytic theory to probe the deeper psychological impacts of social and political structures. She uses Lacanian psychoanalysis to discuss issues like identity formation, the unconscious, and the symbolic structures that influence how people see themselves and their desires.
4. Identity and Social Change: Salecl investigates how societal changes, particularly through technology and media, influence personal identities and social relations. She looks at how technologies like genetic engineering and information technologies impact notions of self and ethical behavior in societies.
5. Law and Subjectivity: Drawing on her background in legal theory, Salecl explores the relationship between law and the formation of subjectivity. She analyzes how legal discourse and institutions shape personal and collective identities, often framing her discussion within the broader critique of capitalism and neoliberalism.
6. Culture and Crime: Another area of Salecl’s interest is the intersection of culture and crime. She has examined how societal norms and values shape both the criminal justice system and the broader public perceptions of crime and punishment, especially looking at how fear is used in governing populations.

Ayaan Hirsi Ali (November 13, 1969 C.E. – Present): Somali-born Dutch-American activist, feminist, author, scholar and former politician.

Maajid Nawaz (November 2, 1977 C.E. – Present): Maajid Usman Nawaz is a British activist and radio presenter. He was the founding chairman of Quilliam, a counter-extremism think tank that sought to challenge the narratives of Islamist extremists.

Jordan Peterson (June 12, 1962 C.E. – Present): Canadian clinical psychologist, YouTube personality, author, and a professor emeritus at the University of Toronto.

Sam Harris (April 9, 1967 C.E. – Present): American philosopher, neuroscientist, author, and podcast host. His work touches on a wide range of topics, including rationality, religion, ethics, free will, neuroscience, meditation, psychedelics, philosophy of mind, politics, terrorism, and artificial intelligence.

1. The Moral Landscape:
2. Determinism: