Socrates is one of the most influential thinkers in history, yet he wrote nothing. Everything we know about him comes from other people, and they do not always agree. Before judging his trial, we need to know who he was, and how we know it.

His life

Socrates was born in Athens around 470 BCE. His father, Sophroniscus, was a stonemason or sculptor, and his mother, Phaenarete, was a midwife; Socrates later compared his own work to midwifery, helping others give birth to ideas. He married Xanthippe and had three sons. He was not rich, and he became famous for going barefoot, wearing the same cloak in all weather and caring little for money.

He was also a citizen soldier. He served as a heavily armed infantryman in the Peloponnesian War, at Potidaea, Delium and Amphipolis, and his companions praised his courage and endurance. At Potidaea he is said to have saved the life of the young aristocrat Alcibiades.

Our sources

Three writers who knew Socrates give us most of our picture.

• Plato, his most brilliant follower, wrote dialogues in which Socrates is the main speaker. Plato's Apology presents Socrates' speech at his trial.
• Xenophon, a soldier and writer, wrote memoirs of Socrates and his own shorter account of the defense. His Socrates is more practical and conventional.
• Aristophanes, the comic playwright, mocked Socrates in his comedy Clouds (423 BCE), showing him hanging in a basket studying the heavens and running a “thinkery” where students learn to win arguments by trickery.

Because these portraits differ, scholars speak of the Socratic problem: the difficulty of knowing which ideas belonged to the real Socrates rather than to the authors who wrote about him. Many scholars think Plato's earlier dialogues stay closer to the historical Socrates, while in later dialogues Socrates becomes a voice for Plato's own theories.

The oracle

In Plato's Apology, Socrates tells a story. His friend Chaerephon once asked the oracle of Apollo at Delphi whether anyone was wiser than Socrates, and the priestess answered that no one was. Socrates was puzzled, since he believed he knew nothing important. He set out to test the oracle by questioning politicians, poets and craftsmen, people reputed to be wise. He found that they claimed to know things they did not. He concluded that his only advantage was that he knew that he did not know, while they did not realize their own ignorance.

Socrates and the Sophists

In Socrates' lifetime, traveling teachers called Sophists, such as Protagoras and Gorgias, came to Athens and charged high fees to teach young men rhetoric, the art of persuasive speaking, which was the key to success in the Assembly and the courts. Some taught that there was no fixed truth about justice, only arguments that worked. Socrates took no fees and argued against many Sophist ideas. But to ordinary Athenians, a clever talker surrounded by rich young men looked much the same as a Sophist, and Aristophanes' Clouds blurred the difference on purpose.

The method

Socrates' way of doing philosophy was conversation. He would ask someone to define a virtue, such as courage or justice, then ask questions that exposed contradictions in the answer, until the person admitted confusion. This style of questioning is called the elenchus, or Socratic method. It was not meant only to embarrass. Socrates believed that clearing away false beliefs was the first step toward knowledge and a better life.

Young men from wealthy families loved to watch him puncture the self-importance of their elders, and some imitated him. That was part of the problem. To the people he questioned, Socrates could seem arrogant, and his followers insolent.

The divine sign

Socrates also said that since childhood he had experienced a daimonion, a divine sign or inner voice that warned him against certain actions but never told him what to do. He treated it as a gift from the gods. His accusers would treat it as evidence of strange new religion.

Worked example: the Socratic method in action

Here is a short conversation in Socrates' style, set today.

Socrates: You say courage means never retreating. Is that right?

Student: Yes. A brave soldier holds his ground.

Socrates: Suppose a firefighter enters a burning building, sees the roof about to collapse, and pulls her team out. Was she a coward?

Student: No, she was wise to retreat.

Socrates: Then courage is not simply never retreating. Perhaps it involves knowing what is truly worth fearing?

Student: I suppose so. But now I am not sure what courage is.

Notice what happened. The student's definition was tested against a clear case and failed. Socrates did not give a final answer; he left the student knowing less but understanding more. This is uncomfortable, and it is easy to see why people in power might resent it. It is also the root of a habit every free society needs: testing claims, even popular ones, before accepting them.