The Dialogues of Plato, written between 427 and 347 b.c., rank among the most important and influential works in Western thought. Most famous are the first four, in which Plato casts his teacher Socrates as the central disputant in colloquies that brilliantly probe a vast spectrum of philosophical ideas and issues. Socrates' ancient words are still true, and the ideas found in Plato's Dialogues still form the foundation of a thinking person's education....