For Socrates, as for Jesus Christ, we have few biographical details, and of those we do have nearly all come from Plato, his greatest admirer. But it is clear that Socrates contributed three new ideas to the development of philosophy: that goodness consists not in helping friends and harming enemies, but in not harming anyone at all; that goodness and knowledge are one and the same thing; and that for progress to be made in argument, there must be step-by-step agreement between those arguing. Like Jesus, Socrates too was put to death for defying the conventions of his day, and by the manner of his life and death he, too, sets an example which is at the same time an inspiration and an impossible ideal.

All the Plato dialogues are translated by Benjamin Jowett. The Aristophanes is B. B. Rogers, and the Xenophon is H. G. Dakyns.