It was a parallel process, a process of inclusion, that one's resultant idea should be adequate, of rejection or exclusion, that this idea should be not redundant, which Socrates applied [161] to practice; exercising, as we see in the Platonic Dialogues, the two opposed functions of synagôgê and diairesis,+ for the formation of just ideas of Temperance, Wisdom, Bravery, Justice itself--a classification of the phenomena of the entire world of feeling and action. Ideas, if they fulfil their proper purpose, represent to the mind such phenomena, for its convenience, but may easily also misrepresent them. In the transition from the particulars to the general, and again in the transition from the general idea, the mental word, to the spoken or written word, to what we call the definition, a door lies open, both for the adulteration and the diminution of the proper content, of our conception, our definition. The first growth of the Platonic "ideas," as we see it in Socrates, according to the report of Aristotle, provided against this twofold misrepresentation. Its aim is to secure, in the terms of our discourse with others and with ourselves, precise equivalence to what they denote. It was a "mission" to go about Athens and challenge people to guard the inlets of error, in the passage from facts to their thoughts about them, in the passage from thoughts to words. It was an intellectual gymnastic, to test, more exactly than they were in the habit of doing, the equivalence of words they used so constantly as Just, Brave, Beautiful, to the thoughts they had; of those thoughts to the facts of experience, which it was the business of those [162] thoughts precisely to represent; to clear the mental air; to arrange the littered work-chamber of the mind.