Philosophy

Protagoras

c. 490 to 420 BC, Abdera

The first and greatest sophist: man is the measure of all things.

Start learning Protagoras →

Lessons

Man Is the Measure

Protagoras opened his book Truth with the most famous sentence of the sophistic age: ‘Man is the measure of all things - of the things that are, that they are; of the things that are not, that they are not.’…

Truth, Flux, and Appearance

Protagoras’ relativism rests on a picture of a world in flux, perceived by perceivers who are themselves changing, so that perception is always an interaction yielding truth-for-each. Plato linked this to Heraclitus’ do…

The Teacher of Excellence

Protagoras was the first professional sophist - a paid teacher who promised to make young men better : more excellent in managing their households and their city. He taught rhetoric, the art of argument on both sides, a…

Concerning the Gods

Protagoras opened his book On the Gods with a famous declaration of agnosticism: ‘Concerning the gods, I cannot know whether they exist or not, nor of what form they are; many things prevent this knowledge - the o…

The Long Shadow of the Sophist

Condemned by Plato and reduced to a byword for fallacy, Protagoras was rehabilitated by modern thinkers who saw in ‘man is the measure’ a profound anticipation of pragmatism, perspectivism, and the modern cr…

More in Philosophy

AristotlePlatoImmanuel KantFriedrich NietzscheConfuciusSenecaEpictetusMarcus Aurelius

epoché — a humanities education that remembers you.