God is utterly simple; for every composite being necessarily has a cause of its own composition, and so, since God is the first principle of all things, there can be no real composition whatever in God. Now, in an utterly simple being there can be nothing that is not that simple being itself. In God, therefore, whatever really is, is the same as God, is the same as that which is, is the same as that which subsists, and hence necessarily subsists.
