Protagoras Relativism Quotes & Sayings

Man is the measure of all things — Protagoras

Socrates : Then would he not be conceding that his own opinion is false, if he grants that the opinion of those who think he is in error is true?
Theodorus : Necessarily.
Socrates : But the others do not concede that they are in error, do they?
Theodorus : No, they do not.
Socrates : And he, in turn, according to his writings, grants that this opinion also is true.
Theodorus : Evidently.
Socrates : Then all men, beginning with Protagoras, will dispute - or rather, he will grant, after he once concedes that the opinion of the man who holds the opposite view is true - even Protagoras himself, I say, will concede that neither a dog nor any casual man is a measure of anything whatsoever that he has not learned. Is not that the case?
Theodorus : Yes.
Socrates : Then since the "truth" of Protagoras is disputed by all, it would be true to nobody, neither to anyone else nor to him.
[171b-c] — Plato