Modern philosophy since Immanuel Kant has tended to deny the possibility of making a synthetic a priori claim about experience. Kant thought in his Prolegomena To Any Future Metaphysics, no necessary, a priori laws of experience could be posited—which are themselves the foundations of metaphysical claims, and, without these, metaphysics was no longer possible.
Kant boldly proclaimed
“If anyone thinks himself offended, he is at liberty to refute my charge by producing a single synthetic proposition belonging to metaphysics which he would prove dogmatically a priori; for until he has actually performed this feat, I shall not grant that he has truly advanced science, even though this proposition should be sufficiently confirmed by common experience.”
Edmund Husserl responded to this challenge in 1901 in his work Logical Investigations, Volume II, under Investigation III. Following on from Franz Brentano’s lead regarding mereology. Mereology is the logic of the relationship of parts to wholes. A “part,” Husserl argues, is anything which can be distinguished in an object, such as color, shape, or extension, in contrast to the intentional object as a whole. However, an important distinction must be made: some parts are independent, while others are dependent. A dependent part is defined according to “its inability to exist by itself.”
A head can certainly be presented apart from the person that has it. A color, form, etc., is not presentable in this fashion, it needs a substrate, in which is can be exclusively noticed, but from which it cannot be taken out.
Thus, Husserl argues, there can be no experience of independent color or form (shape), apart from an object of some kind, acting as its substrate. Following upon these lines, Husserl explains that there are foundational parts, in which it is posited that if A cannot be without B, then A requires the foundation of B. So, for example, extension in space requires some body upon which extension is predicated or founded. Extension cannot be without a substrate, and therefore substrata are foundational for extension. Likewise, a color cannot exist without some space that it covers.
With that in mind, it becomes clear that “red,” for example, would be a non-independent part of anything “colored.” “Redness” must have as its substrate some object as its foundation, as it is never the case that one experience’s “redness” without a foundational object of some kind. Likewise, “shape” and “extension” are never experienced apart from some object upon which these qualities are based. These facts, then, are clearly a priori. In other words, they are universally necessary, as we are constituted as humans to experience reality in this fashion. These facts, however, are also not truths bound up in the definition of color or extension or shape; they are thus synthetic. They tell us something about our experience—metaphysical facts about our experience.
Husserl, by a simple but profound analysis of mereology emphatically answered Kant’s charge.
[Serious students of Kalam will have noted here how all of the above is covered in basic introductory classes. Remember the jawhar and the arad? This is just one example of what Westerners today think is an advanced discussion, that was already covered centuries prior by Muslims. We could cite dozens of other such discussions. Don’t let morons larping as wannabe Mujaddids of the Ashari and Maturidi schools fool you with their intimidation through obfuscation tactics. They don’t know anything about Kalam nor do they know anything about Western philosophy or history or the world we live in. More resources on how to study these subjects seriously, from the Ancient Greeks to the Muslims to the Pittsburgh School in modern times, will be posted in the future. Insha’Allah.]