Book 12
4
Hence these thinkers must have had some conception of matter. All things which change have matter, but different things have different kinds; and of eternal things such as are not generable but are movable by locomotion have matter; matter, however, which admits not of generation, but of motion from one place to another.Cf. Aristot. Met. 12.1.3, Aristot. Met. 8.1.7, 8.
4
One might raise the question from what sort of not-being generation takes place; for not-being has three senses.(1) the negation of a category, (2) falsity, (3) unrealized potentiality. Cf. Aristot. Met. 14.2.10. If a thing exists through a potentiality, nevertheless it is not through a potentiality for any chance thing; different things are derived from different things.
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Nor is it satisfactory to say that all things were together, for they differ in their matter, since otherwise why did they become an infinity and not one? For Mind is one; so that if matter is also one, only that could have come to be in actuality whose matter existed potentially. The causes and principles, then, are three; two being the pair of contraries, of which one is the formula or form and the other the privation, and the third being the matter.This classification is found in Aristot. Physics 1.6, 7, but is foreign to the main treatise of the Metaphysics. See Introduction.
