Kant's Theology of the Understanding

Schopenhauer thinks what the understanding does is all explainable in terms of the sufficient on. He's not going to make any assertions about whether things in themselves are ideas or matter. And will just say all we can know about objects is how they are in terms of our cognize them as subjects. So that's transcendental idealism for kant, because he wants to distinguish it from something like berkeley in idealism where everything in the world is mental.