Abstract

In Aristotle, substance, being specified in Z17 as cause and principle, is to be understood according to the analogical theory of principles and causes, namely form, matter and privation. These three causes involve potentiality and actuality, since form, privation, and the compound substance are in actuality, while matter is in potentiality. ≪What a substance is≫ depends on the connection between these three principles. In order to grasp the meaning of this connection, one has to put the analogical theory of principles back in its context, where previous theories on contraries are amended.The amendment of previous theories of principles relies on positing a third term, matter, between both opposites, i.e. form and privation. The implied distinction between matter and privation allows an understanding of generation which makes it compatible with substance. While generation removes privation, substance as form gives shape to matter, final matter and shape being identical to one another. Predication of matter by form supplies a relevant pattern for considering the relationship between matter, form and privation. At the same time, predication of matter by form provides both a renovated theory of opposites and a new theory of form as a cause, i.e. a theory of form as actuality.