In contrast with the Sophists, a series of schools of philosophy also arose in Athens. These in a way were the outgrowth of the work of Socrates. Accepting the Sophists' dictum that "man is the measure of all things," he tried to turn youths from the baser individualism of the Sophists of his day to the larger general truths which measure the life of a true man. In particular he tried to show that the greatest of all arts-- the art of living a good life--called for correct individual thinking and a knowledge of the right. "Know thyself" was his great guiding principle. His emphasis was on the problems of everyday morality. Frankly accepting the change from the old education as a change that could not be avoided, he sought to formulate a new basis for education in personal morality and virtue, and as a substitute for the old training for service to the State. He taught by conversation, engaging men in argument as he met them in the street, and showing to them their ignorance (R. 9). Even in Athens, where free speech was enjoyed more than anywhere else in the world at that time, such a shrewd questioner would naturally make enemies, and in 399 B.C. at the age of seventy-one, he was condemned to death by the Athenian populace on the charge of impiety and corrupting the youth of Athens. [Illustration: FIG. 12 SOCRATES (469-399 B.C.) (After a marble bust in the Vatican Gallery, at Rome)] Socrates' greatest disciple was a citizen of wealth by the name of Plato, who had abandoned a political career for the charms of philosophy, and to him we owe our chief information as to the work and aims of Socrates. In 386 B.C. he founded the Academy, where he passed almost forty years in lecturing and writing. His school, which formed a model for others, consisted of a union of teachers and students who possessed in common a chapel, library, lecture-rooms, and living-rooms. Philosophy, mathematics, and science were taught, and women as well as men were admitted. Other schools of importance in Athens were the Lyceum, founded in 335 B.C. by a foreign-born pupil of Plato's by the name of Aristotle, who did a remarkable work in organizing the known knowledge of his time; [7] the school of the Stoics, founded by Zeno in 308 B.C.; and the school of the Epicureans, founded by Epicurus in 306 B.C. Each of these schools offered a philosophical solution of the problem of life, and Plato and Aristotle wrote treatises on education as well. Each school evolved into a form of religious brotherhood which perpetuated the organization after the death of the master. In time these became largely schools for expounding the philosophy of the founder. [Illustration: FIG. 13. EVOLUTION OF THE GREEK UNIVERSITY]