This philosophy, called Empirio-criticism, is not, however, a realistic but an idealistic dualism, nor can it be called materialism.
1 Hegel will allow no dualism of fact and principles.
So far as we can see, on the other hand, Basilides appears actually to represent a further development of Iranian dualism, which later produced the religious system of Mani.
The threatened dualism of ideal and material becomes for Aristotle mainly a contrast of matter and form; the lower stage in development desires or aims at the higher, matter more and more tending to pass into form, till God is form without any matter.
Against Manichaean dualism he had vindicated free will; but as against Pelagianism he taught the bondage of sinful man - a position accepted in the East but never welcome there, and not more than half welcome even in the West.