[Sidenote: Socrates and the autonomy of mind.] If the happy freedom of the Greeks from religious dogma made them the first natural philosophers, their happy political freedom made them the first moralists. It was no accident that Socrates walked the Athenian agora; it was no petty patriotism that made him shrink from any other scene. His science had its roots there, in the personal independence, intellectual vivacity, and clever dialectic of his countrymen. Ideal science lives in discourse; it consists in the active exercise of reason, in signification, appreciation, intent, and self-expression. Its sum total is to know oneself, not as psychology or anthropology might describe a man, but to know, as the saying is, one’s own mind. Nor is he who knows his own mind forbidden to change it; the dialectician has nothing to do with future possibilities or with the opinion of anyone but the man addressed. This kind of truth is but adequate veracity; its only object is its own intent. Having developed in the spirit the consciousness of its meanings and purposes, Socrates rescued logic and ethics for ever from authority. With his friends the Sophists, he made man the measure of all things, after bidding him measure himself, as they neglected to do, by his own ideal. That brave humanity which had first raised its head in Hellas and had endowed so many things in heaven and earth, where everything was hitherto monstrous, with proportion and use, so that man’s works might justify themselves to his mind, now found in Socrates its precise definition; and it was naturally where the Life of Reason had been long cultivated that it came finally to be conceived. [Sidenote: Plato gave the ideal its full expression.]