Protagoras
Protagoras (
Greek: Πρωταγόρας) (c.
481–c.
420 BC) was a
pre-Socratic philosopher and is numbered as one of the
sophists by
Plato. In his dialogue
Protagoras, Plato credits him with having invented the role of the professional sophist or teacher of virtue.
Protagoras was born in
Abdera, Thrace, in
Ancient Greece. He was famous as a teacher of rhetoric and debate which were vital to Greek social life. Due to those interests, he was fascinated by the study of
orthoepeia, or the correct use of words.
His most famous saying is: "Man is the measure of all things: of things which are, that they are so, and of things which are not, that they are not." The word "man" here is used generically meaning any human being. Despite the fame of this phrase, it has been passed down to us without any context, as is so often the case with the presocratics, and its meaning isn't entirely clear. It was Protagoras' teachings that spurred later philosophers such as
Plato to search for objective, transcendent guidelines to underlie moral behavior.
Protagoras was also a famous proponent of
agnosticism. In "On the Gods" he wrote: "Concerning the gods, I have no means of knowing whether they exist or not or of what sort they may be, because of the obscurity of the subject, and the brevity of human life."
The
Protagoras crater on the
Moon was named in his honour.
Even though Protagoras was a contemporary of
Socrates, the philosopher of Abdera is considered a presocratic thinker. He followed the
Ionian tradition that distinguishes the School of Abdera. The distinctive note of this tradition is criticism, a systematic discussion that can be identified as "presocratic dialectic", an alternative to the Aristotelian demonstrative method which, according to
Karl Popper, has the fault of being
dogmatic. The main contribution of Protagoras was perhaps his method of finding a better argument by discarding the less viable one. This is known as "Antilogies", and consists of two premises; the first is "Before any uncertainty two opposite theses can validly be confronted", the second is its complement: the need to "strengthen the weaker argument".
Protagoras knew that the less appealing argument could hide the best answer, which is why he stated that it was constantly necessary to strengthen the weakest argument. Having been born before Socrates himself, this progressive viewpoint in the development of consensual truth could conceivably have contributed to the progressive styles of many of the other great minds which followed him.
This quotation is recapitulated in Plato's
Theaetetus, section 152a. [
1]
