That is to say, who works unconditionally, being Himself the Unconditioned. The "error of the ancient philosophers" was the error of Plato (Timaeus, 30), who certainly had arrived to some, though an imperfect, knowledge of the Universal Agent. Plato's reluctance to confess God as more than the Demiurge, -- or ordering Mind of the universe, not its Creator, -- came from his discerning, as he thought, the origin of evil in the existence of matter, matter being more or less an irrational product, not originated by mind, and but imperfectly controlled by mind. Monists at least will not deny the derivation of matter from mind. To them, all reality is One and of One: but they deny creation out of nothing, and consider matter a necessary and eternal outcome of the Divine Mind. On Monism St Thomas touches, Chapp. LXXIII-LXXV.

Of God and His Creatures: 2.16