The Principle of Non-Contradiction in Being

Aristotle affirms a real principle in things accounting for the susceptibility of being to manyness, limit and change. We know that monism is incorrect if we trust our senses but understand why potency is a real capacity founded upon act while not being itself actual. The marble is only potentially sculptable but it is of its actual nature to be so. St. Thomas's account of the participation of being by finite creatures is intelligible only in relation to the limitation of act by potency.