Kant calls his Transcendental Deduction "the most difficult thing that could ever be undertaken on behalf of metaphysics" (4:260). Readers have found it not just difficult but downright impossible. I will address two long-standing problems. First, Kant seems to contradict his conclusion at the outset of his proof. He does so in both the 1781 and 1787 editions of his Critique of Pure Reason. Second, Kant seems to argue for his single conclusion twice over in his Critique's 1787 edition. I (...) will propose novel solutions by considering why Kant's Deduction is more difficult than his Transcendental Aesthetic, on one hand, and his 1770 Inaugural Dissertation, on the other. My broader aim is to oppose a subjectivist interpretation of Kant's Deduction with an original interpretation. On the subjectivist interpretation, Kant holds that the categories apply to appearances because appearances necessarily conform to our subjective forms of the understanding. I will argue to the contrary in addressing the first problem. On my interpretation, the reason that the categories apply to appearances is not just because of what our subjective forms of the understanding are. It is because of what objects are as appearances. What are objects as appearances, for Kant? In addressing the second problem, I will argue that they are objects of our possible intuitions and judgments. (shrink)