Lampooned in 406 B.C.E. in a blistering Aristophanic satire, Socrates was tried in 399 B.C.E. on a charge of corrupting the youth, convicted by a jury of about five hundred of his peers, and condemned to death. Glimpsed today through the extant writings of his contemporaries and near-contemporaries, he remains for us as compelling, enigmatic, and elusive a figure as Jesus or Buddha. Although present-day (like ancient Greek) opinion on the real Socrates diverges widely, six classic texts that any informed judgment of him must take into account appear together, for the first time, in this...