REALITY. Metaphysics
St. Thomas is in part the thought of Aristotle, but not limited to accept its teachings without more, but extends them in some places and modifies others.
St. Thomas took the Aristotelian distinction between matter and form, between substance and accident, and between power and act, though the latter gives a new meaning.
Still, the more important is that referring to the analogy of being, which is based on what the body is the essence and the act of being (esse) of that essence.
That comes to a new theory that distinguishes and describes two types of substances, the material entities that are accessible through the senses and that is ontologically divided between the substantial level, where matter is related to the form,...