 The issue of things in themselves affecting us raises another problem for Kant’s theory, for Kant also argues that categories like cause-effect cannot be meaningfully applied to things in themselves. Without an intuition “[the category] has no sense, and is entirely empty of content” (A239/B298). Since things in themselves cannot be intuited, categories (including cause-effect) have no sense or content when applied to things in themselves. Jacobi and others thought this was yet another inconsistency in Kant’s philosophy: he denies that categories can be applied to things in themselves, but then he applies the category cause-effect to them!