Book 14
3
Moreover, all things are generated from contraries as from a substrate, and therefore contraries must most certainly have a substrate. Therefore all contraries are predicated of a subject, and none of them exists separately. But there is no contrary to substance; not only is this apparent, but it is borne out by reasoned consideration.Cf. Aristot. Categories 3b 24-27 Thus none of the contraries is strictly a first principle; the first principle is something different.
4
But the Platonists treat one of the contraries as matter, some opposing the unequal to Unity (on the ground that the former is of the nature of plurality) and others plurality.
5
For according to some,Plato; cf. Aristot. Met. 13.7.5. numbers are generated from the unequal dyad of the Great and Small; and according to another,Probably Speusippus. from plurality; but in both cases they are generated by the essence of unity. For he who speaks of the unequal and Unity as elements, and describes the unequal as a dyad composed of Great and Small, speaks of the unequal, i.e. the Great and Small, as being one; and does not draw the distinction that they are one in formula but not in number.This shows clearly that by the Great-and Small Plato meant a single principle, i.e., indeterminate quantity. Aristotle admits this here because he is contrasting the Great-and Small with the One; but elsewhere he prefers to regard the Platonic material principle as a duality. See Introduction.
