=61.= Of all the companions of Socrates far the most famous is PLATO of Athens (427-347 B.C.), the founder of the philosophical association known as the ‘Academy.’ In the general judgment of lovers of Greek letters he stands out not merely as a great master of Attic prose style, but also as the ablest exponent of the true mind of Socrates[3], and the most brilliant light of Greek philosophy[4]. On the first point this judgment stands unchallenged; for delicate and good-natured wit, felicity of illustration and suggestiveness of thought the Platonic dialogues are unrivalled. But it is only in his earlier writings that we can accept Plato as a representative of Socrates; after the death of his master he travelled for many years in Egypt, Lower Italy, and Sicily, and absorbed in particular much of the teaching of the Pythagoreans. The theory of ‘ideas,’ the special characteristic of Plato’s later work, is not strictly Socratic. Neither, we must add, is it of first-rate importance in the history of human thought; from our point of view it lies apart from the main current both of speculation and of practice. It was a still-born theory, not accepted even by Plato’s successors in the control of the Academy[5]. We are therefore very little concerned with the direct teaching of Plato; but all the more readily it should be acknowledged that the Stoics were often indebted to him for help in the treatment of important details, and that the Platonic attitude remained for them a factor of which they needed continuously to take account. [Sidenote: Plato’s realism.]