Abstract

In the Fourth Meditation, Descartes asks: 'If God is no deceiver, why do we sometimes err?' Descartes's answer (despite initial appearances) is both systematic and necessary for his epistemological project. Two atheistic arguments from error purport to show that reason both proves and disproves God's existence. Descartes must block them to escape scepticism. He offers a mixed theodicy: the value of free will justifies God in allowing our actual errors, and the perfection of the universe may justify God in making us able to err. Though internally coherent, Descartes's theodicy conflicts with his view of divine providence