Socrates (c. 470–399 BCE) wrote no philosophical books. What we know comes mainly through other authors — above all Plato and Xenophon — which means “the historical Socrates” and “Plato's Socrates” cannot always be cleanly separated.

Big idea: Socrates turns confidence into a research problem. If you claim to know what courage, justice, piety, or virtue is, can your definition survive disciplined questioning?

The Socratic elenchus is not merely “ask lots of questions.” Socrates elicits a claim, draws out its implications, and exposes inconsistency between what the speaker says and other beliefs the speaker accepts. The result is often aporia — productive puzzlement rather than a neat final doctrine.

His ethical pressure is equally important: an unexamined life can be badly guided even when socially successful. In Plato's Apology, Socrates treats awareness of his own ignorance as intellectually superior to confident false knowledge.

A common misconception is that the “Socratic method” is simply a classroom technique where teachers lead students to the teacher's predetermined answer. The philosophical version is more dangerous: the questioner should also be open to discovering that the supposed answer does not hold up.

Socrates was tried and executed by Athens on charges including impiety and corrupting the young. His willingness to accept the death sentence rather than abandon his activity turned his life into part of the philosophical argument.