Socrates, herm with a restored nose probably copied from the Greek original by Lysippus, c. —Courtesy of the Soprintendenza alle Antichita della Campania, Naples
(born c. 470, Athensdied 399 BC, Athens) Greek philosopher whose way of life, character, and thought exerted a profound influence on ancient and modern philosophy. Because he wrote nothing, information about his personality and doctrine is derived chiefly from depictions of his conversations and other information in the dialogues of Plato, in the Memorabilia of Xenophon, and in various writings of Aristotle. He fought bravely in the Peloponnesian War and later served in the Athenian boule (assembly). Socrates considered it his religious duty to call his fellow citizens to the examined life by engaging them in philosophical conversation. His contribution to these exchanges typically consisted of a series of probing questions that cumulatively revealed his interlocutor's complete ignorance of the subject under discussion; such cross-examination used as a pedagogical technique has been called the Socratic method. Though Socrates characteristically professed his own ignorance regarding many of the (mainly ethical) subjects he investigated (e.g., the nature of piety), he did hold certain convictions with confidence, including that: (1) human wisdom begins with the recognition of one's own ignorance; (2) the unexamined life is not worth living; (3) ethical virtue is the only thing that matters; and (4) a good person can never be harmed, because whatever misfortune he may suffer, his virtue will remain intact. His students and admirers included, in addition to Plato, Alcibiades, who betrayed Athens in the Peloponnesian War, and Critias (c. 480–403 BC), who was one of the Thirty Tyrants imposed on Athens after its defeat by Sparta. Because he was connected with these two men, but also because his habit of exposing the ignorance of his fellow citizens had made him widely hated and feared, Socrates was tried on charges of impiety and corrupting the youth and condemned to death by poisoning (the poison probably being hemlock) in 399 BC; he submitted to the sentence willingly. Plato's Apology purports to be the speech that Socrates gave in his own defense. As depicted in the Apology, Socrates' trial and death raise vital questions about the nature of democracy, the value of free speech, and the potential conflict between moral and religious obligation and the laws of the state.