Protagoras of Abdera

Born circa 480 B.C.; died circa 410 B.C. Ancient Greek philosopher and founder of the school of Sophists.

Protagoras traveled throughout Greece disseminating his doctrines. He visited Athens many times and at one time was close to Pericles and Euripides. When the oligarchy took power in 411 B.C., he was accused of atheism and his book about the gods was burned in Athens. The contemporaries of Protagoras were especially struck by the fact that he organized public debates, took fees for teaching, and started to employ sophisms. The treatises of Protagoras have not come down to us.

Protagoras became famous for his thesis that “man is the measure of all things, of things that are that they are and of things that are not that they are not.” Protagoras interpreted the subjectivism contained here as an inference from the doctrine of Heraclitus (or, rather, his followers) about the universal fluidity of things. If everything changes every instant, then everything exists only to the extent that it can be grasped by an individual at any one moment; about everything one can say at the same time both one thing and something else that contradicts it. This relativism was expressed by Protagoras in the area of religion as well: “About the gods I cannot know whether they exist or do not exist or what they look like.” Protagoras apparently recognized the existence of both the gods and the world as a whole, but in contrast to the ancient natural philosophers he denied the possibility of a reliable comprehension of the objective world and acknowledged only the fluidity of sen-sate phenomena.

In ethics and politics, Protagoras was evidently not given to a consistent expression of his relativism. He held that even if we do not know the truth, we can know what is useful; natural and state laws tell us that. Legislation is necessary insofar as the gods have endowed us from the very beginning with “justice” and “shame”; here Protagoras was an adherent of a certain kind of pragmatism.

There is evidence of Protagoras’ pursuits in grammar, rhetoric, and art education.