Protagoras · Philosophy
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 critique of objective truth. His relativism became one of the central, contested ideas of modern thought.
For most of the two thousand years after his death, Protagoras existed in the Western imagination only as a defeated opponent - the foil Plato set up in order to knock down, the ‘sophist’ whose very name became a slur. This was not because Protagoras’ ideas had been shown to be worthless, but because his chief expositor was also his chief antagonist, and that antagonist happened to be the most influential philosopher and one of the greatest writers in the entire tradition. Plato’s dialogues - the Protagoras, the Theaetetus, the Gorgias, the Sophist - became canonical texts, read and revered for millennia, and in all of them the sophist is cast as the embodiment of intellectual error and moral danger: the relativist whose doctrine self-destructs, the seller of persuasion indifferent to truth, the dark double of the true philosopher. Protagoras’ own books did not survive; his case was heard only through the mouth of the prosecutor. Small wonder the verdict went against him.
This is one of the most striking examples in intellectual history of how reputations are made and unmade by the accidents of transmission and the talents of one’s enemies. Had Protagoras’ own works survived, or had a defender of comparable genius taken up his cause, the history of the very word ‘sophist’ - and perhaps of relativism itself - might have run quite differently. Instead, for two millennia, to be a ‘sophist’ was to be a clever fraud, and ‘man is the measure’ was remembered chiefly as the doctrine Plato had triumphantly refuted. The rehabilitation of Protagoras - the recovery of the serious thinker behind the Platonic caricature - would have to wait until the modern age, when new philosophical movements arose that found in his ancient relativism not an error to be refuted but an anticipation of their own most cherished insights. The villain of the dialogues was about to become a prophet.
The first great modern rehabilitation of Protagoras came from the pragmatist movement at the turn of the twentieth century, and especially from the English philosopher F. C. S. Schiller, who explicitly took up Protagoras’ banner and even called his own version of pragmatism ‘Humanism,’ in conscious homage to the man-measure doctrine. Schiller and his greater American ally William James found in Protagoras a prophet of their central conviction: that truth is not a fixed correspondence to a ready-made reality but is bound up with human purposes, needs, and experience - that truth is, in some sense, made rather than found, and that the human knower is an active participant in what counts as true, not a passive mirror of an independent world. James’ famous (and much-misunderstood) formula that the true is ‘what works,’ what proves useful and satisfactory in the conduct of life, can be read as a sophisticated descendant of ‘man is the measure’: the standard of truth is brought back, once again, to the human and the experiential.
This is the opening of the lesson. The rest — the dialogue, the primary source, and the recall — is in the app.
You learned that Protagoras, long dismissed as a mere sophist by Plato’s influential polemic, was rehabilitated in modern times: the pragmatists (F. C. S. Schiller, William James) hailed ‘man is the measure’ as an anticipation of their view that truth is what works for human purposes; Nietzsche’s perspectivism (‘there…
Leads to Friedrich Nietzsche.
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