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Page history last edited by lindsey.spring 11 years, 8 months ago



Protagoras   created by Lindsey Spring                  


Birth:  No later than 490 B.C.E. in Abdera, a city northeast of Greece

Death:  Approximately 420 B.C.E.

(Note: Protagoras’s exact birth and death are unknown. However, in Plato’s Protagoras Protagoras says to Socrates, Prodicus, and Hippia “in point of age I could be the father of anyone of you” (317a). This comment influenced the dates listed above.)


Protagoras is a notable Sophist associated with the Older Sophists and was considered a great thinker.  In fact, he is the first Sophist believed to accept money for his teachings, which took place over the span of forty years.  For the forty years he was teaching, Protagoras travelled Greece and lived in Athens. When he resided in Athens, he had strong ties to Periciles. Protagoras taught public speaking, criticism of poetry, citizenship, and grammar – the only subjects he found necessary to live a good life – to wealthy young men.  His students can be divided into two groups: young men interested in politics and young men interested in becoming Sophists. Protagoras taught his students by using lectures, analysis, and discussions.  He was proud to be a Sophist and believed he was skilled in political and civic virtue, giving long speeches, and a method of questioning and answering he developed.

Protagoras claimed he could teach his students the virtue and political arts necessary to live a good life – or a virtuous life – at home and as a citizen.  At home a student of Protagoras would be able to manage his household, family, and personal affairs in the best way.  As a citizen, a student of Protagoras would gain political power. Protagoras also promised students he could make a weaker argument stronger and could teach those skills to his students. Socrates and Aristotle, as well as others, believed virtue could not be taught and criticized Protagoras for believing he could teach it.  Many people also questioned the moral intentions of Protagoras’ teachings.

Protagoras is well known for four doctrines.

1.  He strongly stressed ortheopeia (grammar) and the correct use and placement of words. Protagoras was on of the first teachers to emphasize these concepts.

2. Protagoras is also associated with agnosticism. He admitted he could not prove or disprove that the gods existed: "Concerning the gods, I cannot know either that they exist of that they do not exist". This sentence opened Protagoras' "On the Gods" and caused Protagoras to be heavily criticized and sent away from Athens.   

3. Protagoras believed there were two sides to every issue and that in an argument there would be one winner and one loser. Thus, Protagoras taught the importance of using certain techniques when speaking to make one's opinion and perspective appear to be the better, stronger side of the argument.

4. His man-measure statement – “man is the measure of all things” – is his most well known doctrine.  Protagoras believed that observations were relative to the individual observer, and that all observations were valid for the observer.



Protagoras is associated with several written works of ancient Greece, although only frangments of his own works exist.  He is the central figure in Plato’s Protagoras and is referred to in Plato’s Menos, Sextus Empiricus' Outlines of Pyrrhonism, Diogenes Laertes' Lives of the Eminent Philosophers, Plutrach's Pericles, and Aristotle's Rhetoric.  Aristophane attacks Protagoras’s teachings in The Clouds. Unfortunately, written works by Protagoras are limited since only pieces of any of his works have survived.  “Truth” and “On the Gods” are the two surviving works by Protagoras.

 Protagoras was influenced by Eleastics and Heraclitus.  Similarities in Protagoras’s teachings and Disso Logi suggest that the anonymous author was influenced by Protagoras.    




Bartlett, Robert C. "Political Philosophy and Sophistry: An Introduction to Plato's Protagoras." American Journal of Political Science 47.4 (2003): 612-624. 

Guthrie, W.K.C. The Sophists. New York: Cambridge University Press, 1971.

Plato. Protagoras and Menos. Trans. Robert C. Bartlett. Ithaca, NY: Cornell University Press, 2004.

Poster, Carol. Protagoras. The Internet Encyclopedia of Philosophy. 27 April 2005. Web. 26 September 2009. <http://www.iep.utm.edu/protagor/#H4>

Schiappa, Edward. Protagoras and Logos: A Study in Greek Philosophy and Rhetoric. 2nd ed. Columbia, SC: University of South Carolina Press, 2003.

Segvic, Heda. From Protagoras to Aristotle: Essays in Ancient Moral Philosophy. Princeton, NJ: Princeton University Press, 2009.

Versenyi, Laszlo. "Protagoras' Man-Measure Fragment." The American Journal of Philology 83.2 (1962): 178-184. 

Comments (2)

Tristan Towne said

at 9:38 pm on Sep 27, 2009

I find it interesting the controversies involving the "man-measure" philosophy, I guess because it seems ironic that subjectivity and ego would threaten Greek ideals. I would like to know more about his alleged involvement in the trial of Socratesand and also whether his controversial ideas ultimately affected his own career and life.

jousas@... said

at 11:10 am on Sep 28, 2009

If man is the measure of all things - then does it follow that men (in number) are a more accurate measure of things than a man (singular)? Is a group of men a "better" measure of all things than a man alone? I wonder how this logic would play out in a greek court - where there are always many "judges/spectators" but usually only one accused.

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