From the very centre of the disturbance came the new spirit of order and restoration: Socrates, the Athenian, saved Greece. The older philosophers had discussed nature; he turned all his attention to practical human life. Like the Sophists, he trusted human reason; but unlike them, he aimed not at a display of intellectual dexterity but at reaching the actual basis of human morality, society and politics. Human conduct was the sole subject of his thought and his conversation. Hence the definite, practical value of his influence: his teaching stood in the closest possible relation to life and to the problems of the time. On the other hand, he began with introspection; self-knowledge was what he demanded of every disciple. Hence the inexhaustible significance of his work for philosophy. He gave no set lessons to his pupils, delivered no lectures, wrote no books. He spent his whole time in conversation with individuals, proceeding always by question and answer, thus compelling his companion to think for himself. His extraordinary intellectual skill and the loftiness and simplicity of his character drew all the best intellects of Athens around him. But what gives him his unchallenged supremacy in the history of Greek thought is the fact, that in his hands the sceptical thought, which had caused such dismay everywhere, proved to be the very means of revealing the great realities which men had feared for.[130] In 399 B. C., when he was an old man of seventy years of age, a number of his fellow-citizens brought a criminal case against him, charging him with corrupting the youth of Athens and with impiety. He was tried, found guilty and sentenced to death. A month later he drank the hemlock—such was the Athenian mode of execution—surrounded by his friends.[131] How tragic! Athens, “the school of Hellas,”[132] kills her greatest teacher! Socrates, the father of ethical philosophy, the founder of the critical method, the ideal instructor, dies as an impious corruptor of the youth of Athens! But Socrates was not merely the greatest teacher of his day. All subsequent Greek philosophy is filled with his spirit; indeed the leading schools of thought were founded by his pupils.[133] Consequently he is the fountain-head of all Western philosophy and science; for in both Greece was the school-mistress of Europe. Among all the disciples, Plato best represents the master’s spirit. The Megarians, the Cynics, the Cyrenaics, and, at a later date, the Stoics and the Epicureans, certainly carried on the work of Socrates, but they are deflections from the straight line: they are “imperfect schools,” as Zeller calls them.[134] Plato is in the direct line of succession.