Various Ideas of Reason and how they Mislead the Understanding

In the last part of his book, Kant talks about how the numerous ideas of reason and how the mislead the understanding into posing insoluble metaphysical questions. Kant, like Hume, draws a distinction between metaphysics from mathematics and science. But instead, he says that the former has bounds while the later two don't have any bounds, but instead have two limits. Math an Science are complete and they are limited only in that their scope is not absolutely general. Math can't answer metaphysical questions & science can't give us insight to into things in themselves. But morality and mathematics aren't needed in mathematical explanations and the nature of things in themselves does not affect the advancement of science.

Metaphysics according to Kant is bounded. Why? Because reason poses questions for itself that it cannot answer. However, in these questionings, our reason bumps against boundaries that it can't got past. This includes the fact that we can't gain definite knowledge outside our experience. But this is useful to us. Although we can't go beyond them, we can infer that there exists something beyond them. We can also infer the connection that they must have with the world that we do perceive.

For Kant, we can't prove anything about the existence of God or His nature.