be our duty where the safety of the truth is concerned, to upset if need be even our own theories, specially as we are lovers of wisdom: for since both are dear to us, we are bound to prefer the truth. Now they who invented this doctrine of εἴδη, did not apply it to those things in which they spoke of priority and posteriority, and so they never made any ἰδέα of numbers; but good is predicated in the categories of Substance, Quality, and Relation; now that which exists of itself, i.e. Substance, is prior in the nature of things to that which is relative, because this latter is an off-shoot, as it were, and result of that which is; on their own principle then there cannot be a common ἰδέα in the case of these.
In the next place, since good is predicated in as many ways as there are modes of existence [for it is predicated in the category of Substance, as God, Intellect—and in that of Quality, as The Virtues—and in that of Quantity, as The Mean—and in that of Relation, as The Useful—and in that of Time, as Opportunity—and in that of Place, as Abode; and other such like things], it manifestly cannot be something common and universal and one in all: else it would not have been predicated in all the categories, but in one only.
Thirdly, since those things which range under one ἰδέα are also under the cognisance of one science, there would have been, on their theory, only one science taking cognisance of all goods collectively: but in fact there are many even for those which range under one category: for instance, of Opportunity or Seasonableness (which I have before mentioned as being in the category of Time), the science is, in war, generalship; in disease, medical science; and of the Mean (which I quoted before as being in the category of Quantity), in food, the medical science; and in labour or exercise, the gymnastic science. A person might fairly doubt also what in the world they mean by very-this that or the other, since, as they would themselves allow, the account of the humanity is one and the same in the very-Man, and in any individual Man: for so far as the individual and the very-Man are both Man, they will not differ at all: and if so, then very-good