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). Kant, of course, was steeped in ideas that the categories of understanding, which shape our experience of the external world, issue from some transcendental apperception – essentially a soul, or unique human rationality.
What is it that makes an object the thing that it is? Is it some kind of substance onto which properties are predicated? Can two (or more) things colocalize (there exists in a single region of spacetime both a thing I call my hand and a thing I call my fist)? In what follows, I am going to riff on some ideas I have for a theory of thingness.