 The main difference between idealism and an indirect realism concerns not so much the metaphysics of perception as a larger metaphysical view about what else exists outside of the mind. Berkeley and Descartes agree about the direct objects of perception, but Descartes posits an additional stratum of mind-independent external objects in addition. The idealist denies that there is a veil of perception not because Descartes was wrong about the nature of perception, but because he was wrong about the natures of cats and rocks.