Protagoras (c. 490 – c. 420 BC) was a pre-Socratic Greek philosopher born in Abdera, northeast Greece.
Protagoras was a teacher and lecturer who traveled widely. He became the advisor to Athenian democrat Pericles, the ruler of the city state of Athens, who instructed him to write the constitution for the colony of Thurii in 444 BC. Although traveling widely, Athens was the city in which Protagoras spent most of his life. As a teacher, Protagoras earned his living from lecturing in oratory, public speaking, grammar, and poetry, and was known for the high fees charged for his serviced. However, ancient legends, which accumulated around him and are likely unhistorical, include Protagoras studying studied with the atomist philosopher Democritus, being jailed for his views, having his works and intellectual material burned, and him fleeing from Athens.
Much of what historians learn about Protagoras come from Plato’s writings. Plato referred to Protagoras, and several others, as sophists. These men were traveling intellectuals and experts in rhetoric, and who taught others how to speak in assemblies and in law courts, both necessary and highly valued skills within Athenian society. They were often private tutors to the youth of the upper classes.
Perhaps the major theme within Protagoras’ work was his subjectivist philosophy which argued that interpretations of reality is relative to individuals. This is expressed in his statement that “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.” He also claimed to be able to make the worse (or weaker) argument appear the better (or stronger). Theologically, he claimed that humans are unable to tell whether or not the gods existed. Protagoras was agnostic, possibly atheistic, concerning the Greek pantheon of gods, and this has led some historians to suggest that this could be behind the purported burning of his books by the Athenians.
Protagoras’ subjectivist philosophy likely did not mean that he did not believe truth to exist; rather, he likely meant that one’s understanding and apprehension of truth is relative to individual perception, and that what a person holds as true will be true to that individual despite any evidence to the contrary. Within this lies arguably his greatest contribution to western thought in that the world one person sees may be radically different from the world his or her neighbour experiences.
According to legend, Protagoras was charged with impiety, a significant offense in Ancient Greece that could result in death, and that while fleeing the colony of Sicily he drowned in the sea.