 Here Kant entertains doubts about how a priori knowledge of an intelligible world would be possible. The position of the Inaugural Dissertation is that the intelligible world is independent of the human understanding and of the sensible world, both of which (in different ways) conform to the intelligible world. But, leaving aside questions about what it means for the sensible world to conform to an intelligible world, how is it possible for the human understanding to conform to or grasp an intelligible world? If the intelligible world is independent of our understanding, then it seems that we could grasp it only if we are passively affected by it in some way. But for Kant sensibility is our passive or receptive capacity to be affected by objects that are independent of us (2:392, A51/B75). So the only way we could grasp an intelligible world that is independent of us is through sensibility, which means that our knowledge of it could not be a priori. The pure understanding alone could at best enable us to form representations of an intelligible world. But since these intellectual representations would entirely “depend on our inner activity,” as Kant says to Herz, we have no good reason to believe that they would conform to an independent intelligible world. Such a priori intellectual representations could well be figments of the brain that do not correspond to anything independent of the human mind. In any case, it is completely mysterious how there might come to be a correspondence between purely intellectual representations and an independent intelligible world.