|Who is it?||Greek Philosopher|
|Birth Place||Abdera, Thrace, Ancient Greece, Greek|
|Died On||c. 420 BC|
|Main interests||language, semantics, relativism, rhetoric, agnosticism, ethics|
|Notable ideas||'Sophist' as teacher for hire, 'Man is the measure of all things'|
The titles of his books, such as Technique of Eristics (Technē Eristikōn, literally "Practice of Wranglings"—with wrestling used as a metaphor for intellectual debate), prove that Protagoras also was a Teacher of rhetoric and argumentation. Diogenes Laërtius states that he was one of the first to take part in rhetorical contests in the Olympic games.