Protagoras connected civic education and rhetorical argument with the claim that human measures, practices, and judgments shape what counts as true or useful.
Intellectual setting
As an itinerant teacher in democratic Greek cities, Protagoras became a major target in Plato's portrayal of sophistic education.
Key ideas
Human measure
The famous measure saying generated rival readings about perception, truth, relativism, and practical judgment.
Antilogic argument
Training in opposed arguments made public disagreement an object of skill and reflection rather than simply an obstacle.
Legacy
He remains a focal point for debates about relativism, rhetoric, civic education, and the historical category of the Sophist.