Aristotle, the prince of the philosophers, demonstrated the unity of God; but from the view which he maintained, that matter was eternal, it followed that God could not be the Creator of the world. Again, to assert, as the Peripatetics did, that God's knowledge extends only to the general laws of the universe, and not to individual and accidental things, is tantamount to giving denial to prophecy. One other point shocked the faith of the Motekallamin—the theory of the intellect. The Peripatetics taught that the human soul was only an aptitude—a faculty capable of attaining every variety of passive perfection—and that through information and virtue it became qualified for union with the active intellect, which latter emanates from God. To admit this theory would be to deny the immortality of the soul (see Alexander of Aphrodisias).