There is a kind of problem in Kant which I think is best answered by Jacob Fries. THIS problem is really many aspects of the same problem. how do we know the dinge an sich exists? How can the a priori categories tell us anything about reality since they are all in mind? Is not is or is not a a priori category? With Fries the role of reason or knowledge is expanded into immediate non intuitive knowledge. Normally we would think that there is a kind of immediate knowledge that comes along with perception. That is the second half of the B deduction. But Fries postulates that there is a kind of immediate knowledge that precedes the senses that knows the categories but also the level of knowledge of the One or the Good in Plato and Plotinus..
That should not be taken to dismiss Hegel who I think deals with a lower level of Logos [of Plotinus]. To me that seems clearly what Hegel meant by the Geist.
The next level is the foundationalists, Huemer, Prichard, G. E. Moore. There you are dealing with a level of cognition after we already can perceive universals.
the best approach to fries is leonard nelson and kelley ross--and even there the best i kelley ross because there are things that fries gets wrong and nelson corrects. and other areas the opposite. to get a full and consistent picture the best is kelley ross.
Why Kant is important is that the approach of the Torah is Faith with Reason; and the sort of synthesis of the Rambam is based on Aristotle, and that approach has some major flaws--as pointed out by Berkley and Thomas Reid.
