Abstract

Aristotle claims that sensible substance is composed of form and matter, while he insists that it is a unity in the strictest sense, that is, the same and one, rather than a heap. However, in what sense a composite thing can be a unity? He takes pains to give an answer in Metaphysics. The key solution lies in his account of matter as potentiality and form as actuality. But many scholars are bewildered by his laconic expressions of the solution, and there are mainly two approaches of interpretations. One is ‘projective’, which takes substance as a basically unified concept; matter and form are two derived aspects of the unity. Another approach is ‘explanatory’, which takes form and matter as the real components and attempts to explain how they can constitute a unitary substance in a time and across a time. The main tasks of this paper are to reexamine the problem and the two approaches and to argue that the manner that a substance is unified should be understood in the light of its coming to be; a sensible substance is a diachronic composite and a functional unity.