GENERAL INTRODUCTION
Plato was born in 427 b.c. of Athenian parents who could provide him with the best education of the day, and ample means and leisure throughout his life. He came to manhood in the dismal close of the Peloponnesian War, when Aristophanes was at the height of his success, and Sophocles and Euripides had produced their last plays. As a boy he doubtless heard the lectures of Gorgias, Protagoras, and other sophists, and his early bent seems to have been towards poetry. But his intelligence was too progressive to rest in the agnostic position on which the sophistic culture was based. A century before, Heraclitus had declared knowledge to be impossible, because the objects of sense are continually changing; yet now a certain Cratylus was trying to build a theory of knowledge over the assertion of flux, by developing some hints let fall by its oracular author about the truth contained in names. From this influence Plato passed into contact with Socrates, whose character and gifts have left a singular impress on the thought of mankind. This effect is almost wholly due to Plato's applications and extensions of his master's
