In many of Plato's Dialogues we see no more than the ordered reflex of this process, informal as it was in the actual practice of Socrates. Out of the accidents of a conversation, as from the confused currents of life and action, the typical forms of the vices and virtues emerge in definite outline. The first contention of The Republic, for instance, is to establish in regard to the nature of Justice, terms as exactly conterminous with thoughts, thoughts as exactly conterminous with moral facts, as the notion of carbon is for the naturalist, when it has come to include both charcoal and the diamond, on the basis of the essential law of their operation as experience reveals it. Show us, not merely accidental truths about it; but, by the doing of what (Ti poiousa)+ in the very soul of its possessor, itself by itself, Justice is a good, and Injustice a bad thing. That illustrates exactly what is meant by "an idea," the force of "knowledge through ideas," in the particular instance of Justice. It will include perhaps, on the one hand, forms of Justice so remote from the Justice of our everyday experience as to seem inversions of it; it will clearly exclude, on the other hand, acts and thoughts, not it, yet, phenomenally, so like it, as to deceive the very gods; and its area will be expanded sufficiently to include, not the individual [163] only, but the state. And you, the philosophic student, were to do that, not for one virtue only, but for Piety, and Beauty, and the State itself, and Knowledge, and Opinion, and the Good. Nay, you might go on and do the same thing for the physical, when you came to the end of the moral, world, were life long enough, and if you had the humour for it:--for Motion, Number, Colour, Sound. That, then, was the first growth of the Platonic ideas, as derived immediately from Socrates, whose formal contribution to philosophy had been "universal definitions," developed "inductively," by the twofold method of "inclusion" and "exclusion."