The fact, however, is just the reverse, and the theory is illogical; for whereas the Platonists derive multiplicity from matter although their Form generates only once, note it is obvious that only one table can be made from one piece of timber, and yet he who imposes the form upon it, although he is but one, can make many tables. Such too is the relation of male to female: the female is impregnated in one coition, but one male can impregnate many females. And these relations are analogues of the principles referred to.
This, then, is Plato's verdict upon the question which we are investigating. From this account it is clear that he only employed two causes note: that of the essence, and the material cause; for the Forms are the cause of the essence in everything else, and the One is the cause of it in the Forms.
He also tells us what the material substrate is of which the Forms are predicated in the case of sensible things, and the One in that of the Forms—that it is this the duality, the "Great and Small." Further, he assigned to these two elements respectively the causation of good note and of evil; a problem which, as we have said, note had also been considered by some of the earlier philosophers, e.g. Empedocles and Anaxagoras.
We have given only a concise and summary account of those thinkers who have expressed views about the causes
