Immanuel Kant famously turned the empiricism-rationalism debate on its head by proposing that, instead of our mental representations of reality having to conform to objective reality, it is objective reality that must conform to our mental representations (if such objects are to be represented at all).
Although wrong on many details, I think it would be difficult to proffer a successful argument that our perception of reality isn’t at least in some way shaped by the peculiar form of our consciousness. Unlike Kant, though, I would make this argument from an evolutionary point of view.
Kant distinguishes between the a priori and the a posteriori intuitions in that the former need not be ascertained through empirical senses (experience) and the latter does. The unstated assumption, though, is that if something is a priori, then it cannot arise from anything a posteriori. The fact that space is an a priori presupposition of our experience of objects in the world means that space is something that our consciousness brings to bear on our experiences as a way of organizing the way in which the world is experienced. As such, the existence of space is precluded from objects as they are in themselves (independent of human consciousness). However, if we take evolution as a process that furnished our consciousness with its a priori intuition, then there is a sense that the a priori intuition of space had to be acquired a posteriori: the genes that bestowed upon ancestors of ours the a priori intuition of space were more likely to survive. Thus, in a genetic sense, the a priori intuition of space was acquired a posteriori.
Though, to be fair to Kant, he died before the theory of evolution was discovered. Interestingly, the very discovery of the theory could be applicable to Kant’s idea of the synthetic a priori – evidence of evolution was certainly available to people of Kant’s time, but it took Darwin to “discover” the mechanism of natural (and sexual) selection. Is the inferential movement from the disparate facts to an explanatory theory an instance of the synthetic a priori? Indeed, it almost seems analytic: organisms with features the confer on them better survival skills will survive.
Anyway, what I have in mind is the fact that, absent any sort of soul or unique human rationality separating humans eternally by an insurmountable gulf from other organisms, what can we say about how reality must conform to our minds, and what does this tell us about reality itself? Given that, in the genetic sense discussed above, we have a posteriori acquired our (now) a priori intuitions of things like space and time, then those intuitions must reflect something about the actual world.
We are, in fact, of the same “substance” as all other organisms, from the most humble bacterium to the greatest minds in human history, and what they all have in common is that, in a genetic sense, they have been molded by the environment. Traits – even what appear to us a priori traits like our intuitions of space and time – had to be evolved in particular environments. Some aspects of the environment are transient – the day-to-day weather, and even the climate itself – but other aspects are eternal.
Examples of such (seeming) eternal features of our universe are the a priori intuitions identified by Kant, namely the spatiotemporality of the universe, but also a priori concepts (categories of the understanding) such as cause-and-effect. Certainly, from an evolutionary point of view, being able to grasp such a priori intuitions and concepts conferred survival utility. Does that mean space, time, cause-and-effect, etc. are how the world exists in-itself, or are these concepts just incredibly useful tools that evolution came up with to aid in survival without actually corresponding to the way reality exists in-itself? This seems unlikely as it violates the parsimony of evolution by natural selection. Is it the case that perceiving and conceptualizing the world under such universal laws is some byproduct of a common ancestor of all organisms who operate under these concepts that, perhaps by mere chance, has not been superseded by some other way (whether more or less closely resembling reality in-itself) of navigating the world? Is it even possible to know anything outside of our umwelt?
These ideas are still somewhat half-baked. If anyone has anything to add, I would appreciate it. By the way, check out my video series on Kant’s Critique of Pure Reason: