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The Sophists (Protagoras, Gorgias)
5th century BC· School or movement· Politics, society & justice
Mostly agreedGood evidence; some details uncertain.
Paid traveling teachers of rhetoric and success in 5th-century BC Greece, who questioned whether truth and morality are universal.
See it on the Philosophy map →The idea
Democratic Athens rewarded persuasive speakers, and Sophists charged high fees to train them. Protagoras taught that 'man is the measure of all things': truth is relative to the observer. Gorgias argued that nothing exists, and if it did, it could not be known or communicated. Several held that laws are human convention (nomos), not nature (physis). Main objection, from Socrates and Plato: teaching people to win arguments rather than find truth breeds manipulation.
Why it matters
They opened debates on relativism, natural law and education that still run, and their challenge provoked the ethics of Socrates and Plato.
Where it comes from
Few writings survive; Plato's dialogues Protagoras and Gorgias are main sources, though hostile. Gorgias' speech Encomium of Helen survives complete.
Still debated
Plato's portrait may be unfair. Historians debate whether they were serious thinkers or clever salesmen; 'sophistry' became an insult largely thanks to Plato.
Connections (2)
▸The Sophists (Protagoras, Gorgias) were challenged by SocratesWell documented
The connection
The Sophists taught that truth and justice may be relative and that winning arguments was a marketable skill. Socrates, who took no fees, challenged them in public, arguing that virtue rests on real knowledge, not persuasion. Ironically, many Athenians lumped him in with them.
When and how
Athens, 5th century BC, as Protagoras, Gorgias, Hippias and Thrasymachus visited to teach and perform.
How we know
Plato's Protagoras, Gorgias and Republic Book 1 dramatize the debates; Aristophanes' Clouds (423 BC) mocks Socrates as a Sophist.
Debates and open questions
The debates as written are Plato's dramatizations; whether they happened as shown, and how fairly the Sophists are represented, is uncertain.
▸The Sophists (Protagoras, Gorgias) gave a power-based answer to What is justice?Mostly agreed
The connection
Sophists contrasted nature (physis) with convention (nomos): laws are human agreements, not cosmic truths. Some drew a hard conclusion. In Plato's Republic, Thrasymachus says justice is 'the advantage of the stronger', rules written by rulers for their own benefit. Plato's whole account of justice was built to answer that challenge.
When and how
Athens in the late 5th century BC, during the Peloponnesian War; voiced by Thrasymachus of Chalcedon and Antiphon, and by Callicles in Plato's Gorgias.
How sure are we?
Fragments of Antiphon's On Truth survive on papyrus; Thrasymachus's view is known mainly from Plato, a hostile witness.
Debates and open questions
Whether the Sophists shared any one view: Protagoras taught that everyone needs a sense of justice, and Plato may have made the movement look more cynical than it was.