 To appreciate Malebranche’s epistemological theory, one must remember that he was an orthodox Cartesian dualist and an orthodox Christian. Like Descartes, he maintained that there are two kinds of created substance – minds and bodies – and that the essence of bodies is extension (or spatial dimension). God, in turn, is an infinite, all-perfect, spiritual being. On this traditional Christian conception, it would be heresy to identify God with his creatures, to suppose that God was extended, or to pretend to fathom God’s essence. Concerning the latter, Malebranche stressed that we don’t see God as he is in himself, for God’s essence is perfectly simple, and by his grace we see only the diversity of particular beings. God’s simplicity also entails that he is not extended: