View source for Protagoras

{{Short description|Pre-Socratic Greek philosopher (c.490–c.420 BC)}}
{{other uses}}{{Distinguish|Pythagoras}}{{Infobox philosopher
| region           = [[Western philosophy]]
| era              = [[Pre-Socratic philosophy]]
| image       = [[File:Ribera - Protagoras, 1637.jpg|250px]]
| caption     = ''Protagoras'' by [[Jusepe de Ribera]], 1637
| name             = Protagoras
| birth_place       = [[Abdera, Thrace|Abdera]]
| birth_date       = {{circa|490 BC}}
| death_date       = {{circa|420 BC}} (aged c. 70)
| school_tradition = [[Sophism]]
| main_interests   = [[Language]], [[semantics]], [[relativism]], [[rhetoric]], [[agnosticism]], [[ethics]]
}}

'''Protagoras''' ({{IPAc-en|p|r|əʊ|ˈ|t|æ|g|ər|ə|s|,_|-|æ|s}} {{respell|proh|TAG|ər|əs|,_-|ass}}; {{langx|el|Πρωταγόρας}}; {{circa|490 BC|420 BC}})<ref name=Guthriedate>Guthrie, p. 262–263.</ref> was a [[Pre-Socratic philosophy|pre-Socratic]] [[Ancient Greeks|Greek]] [[philosopher]] and [[rhetoric]]al theorist. He is numbered as one of the [[sophist]]s by [[Plato]]. In his dialogue ''[[Protagoras (dialogue)|Protagoras]]'', Plato credits him with inventing the role of the professional sophist.

Protagoras is also believed to have created a major controversy during ancient times through his statement that "Of all things the measure is Man, of the things that are, that they are, and of the things that are not, that they are not" which was usually rendered simply as "Man is the measure of all things," interpreted (possibly wrongly, since he disagreed{{clarification needed|date=June 2025}}) by Plato to mean that there is no [[Objectivity (philosophy)|objective truth]]; Protagoras seems to have meant that each person's own personal history, experiences and expectations, developed over their lifetime, determine their judgments, opinions, and statements regarding "truth" (which is the title of the book in which Protagoras made this statement). When a person makes a judgment about a certain thing—good or bad or beautiful or unjust—that person will differ from other people's judgments because their experience has been different.<ref>Jaap Mansfeld, article on "Protagoras," p. 44-46, in Heft 44 (1981; Steiner: Wiesbaden) of the journal Hermes, ed. B. Kerferd, The Sophists and Their Legacy: Proceedings of the Fourth International Colloquium on Ancient Philosophy. Held in Cooperation with Projektgruppe Altertumswissenschaften Der Thyssen Stiftung at Bad Homburg, 29th August - 1st September 1979. {{ISBN|9783515034272}}</ref>

This concept of [[individual]] [[Relativism|relativity]] was intended to be provocative; naturally, it was criticized by Plato and other philosophers, contrasting with both popular opinion and other philosophical doctrine that [[reality]] and its [[truth]] must have an objective [[Grounding (metaphysics)|grounding]]. However, it was part of Protagoras' point that the statement is somewhat counterintuitive. He argued that this concept—believing that others' opinions about the world are valid and must be respected, even if our own experience of truth is different—is necessary for a community to base itself and its decisions on open, democratic debate.<ref>Bonazzi, Mauro, "Protagoras", The Stanford Encyclopedia of Philosophy (Fall 2020 Edition), Edward N. Zalta (ed.), URL = <https://plato.stanford.edu/archives/fall2020/entries/protagoras/>.</ref>

==Biography==
Protagoras was born in [[Abdera, Thrace]], opposite the island of [[Thasos]], around 490 BC.<ref name="Guthriedate" /><ref name="Protagoras">{{cite book |last1=Silvermintz |first1=Daniel |title=Protagoras |date=2016 |publisher=Bloomsbury Publishing Plc |isbn=9781472510921}}</ref> According to [[Aulus Gellius]], he originally made his living as a [[porter (carrier)|porter]], but one day he was seen by the philosopher [[Democritus]] carrying a load of small pieces of wood he had tied with a short cord. Democritus realized that Protagoras had tied the load together with such perfect [[geometric]] accuracy that he must be a mathematical [[Child prodigy|prodigy]]. Democritus promptly took him into his own household and taught him [[philosophy]].<ref>Aulus Gellius, ''[[Noctes Atticae]]'' 5.3.</ref> Protagoras became well known in Athens and even became a friend of [[Pericles]].<ref>O'Sullivan, Neil. (1995) "Pericles and Protagoras". ''Greece & Rome'', Vol. 42 (1): 15–23</ref>

The dates of his life are not recorded but extrapolated from writings that have survived the ages. In ''Protagoras'' Plato wrote that, before a gathering of [[Socrates]], [[Prodicus]], and [[Hippias]], Protagoras stated that he was old enough to be the father of any of them. This suggests a birth date of not later than 490 BC. In the ''[[Meno]]'' he is said to have died at approximately the age of 70, after 40 years as a practising Sophist.<ref>Plato, ''Meno'', 91e</ref><ref name="Protagoras2">{{cite book |last1=Silvermintz |first1=Daniel |title=Protagoras |date=2016 |publisher=Bloomsbury Publishing Plc |isbn=9781472510921}}</ref> His death, then, may be presumed to have occurred circa 420 BC, but is not known for certain, since assumptions about it are based on an apparently fake story about his trial for [[asebeia]] (impiety) in Athens.<ref>{{Cite journal |last=Filonik |first=Jakub |date=2013 |title=Athenian impiety trials: a reappraisal |url= https://zenodo.org/record/896899|journal=Dike |volume=16 |issue=16 |pages=36–39 |doi=10.13130/1128-8221/4290 }}</ref>

[[Plutarch]] wrote that Pericles and Protagoras spent a whole day discussing an interesting point of [[Law of obligations|legal responsibility]], that probably involved a more philosophical question of [[Causation (law)|causation]]:<ref>Guthrie, p. 263.</ref> "In an athletic contest, a man had been accidentally hit and killed with a javelin. Was his death to be attributed to the javelin,<!--reflexive is not in the original, 'itself' is a translation error--> to the man who threw it, or to the authorities responsible for the conduct of the games?"<ref>Plutarch, ''Life of Pericles''</ref>

==Philosophy==
[[File:Salvator Rosa - Démocrite et Protagoras.jpg|thumb|285x285px|''[[Democritus]] and Protagoras'' by [[Salvator Rosa]]; it is said that Protagoras was educated on philosophy by Democritus, but this is likely apocryphal.]]
Even though he was mentored by Democritus, Protagoras did not share his enthusiasm for the pursuit of [[mathematics]]. "For perceptible lines are not the kind of things the geometer talks about, since no perceptible thing is straight or curved in that way, nor is a circle tangent to a ruler at a point, but the way Protagoras used to say in refuting the geometers" (Aristotle, Metaphysics 997b34-998a4). Protagoras was skeptical about the application of [[theoretical mathematics]] to the [[Natural environment|natural world]]; he did not believe they were really worth studying at all.  According to Philodemus, Protagoras said that "The subject matter is unknowable and the terminology distasteful".  Nonetheless, mathematics was considered to be by some a very viable form of [[art]], and Protagoras says on [[the arts]], "art (''tekhnê'') without practice and practice without art are nothing" (Stobaeus, ''Selections'' 3.29.80).

Protagoras taught subjects related to [[virtue]] and political life. He especially was involved in the question of whether virtue could be taught, a commonplace issue of fifth century BC Greece, that has been related to modern readers through Plato's dialogue. Rather than educators who offered specific, practical training in rhetoric or public speaking, Protagoras attempted to formulate a reasoned understanding, on a very general level, of a wide range of human phenomena, including language and education. In Plato's ''Protagoras'', he claims to teach "the proper management of one's own affairs, how best to run one's household, and the management of public affairs, how to make the most effective contribution to the affairs of the city by word and action".<ref>Plato, ''Protagoras'', (319a).</ref>

He also seems to have had an interest in "orthoepeia"—the correct use of words—although this topic is more strongly associated with his fellow sophist [[Prodicus]]. In his eponymous Platonic dialogue, Protagoras interprets a poem by Simonides, focusing on the use of words, their literal meaning, and the author's original intent. This type of education would have been useful for the interpretation of laws and other written documents in the Athenian courts.<ref name="poster2005" /> [[Diogenes Laërtius]] reports that Protagoras devised a taxonomy of speech acts, such as assertion, question, answer, command, etc. [[Aristotle]] also says that Protagoras worked on the classification and proper use of grammatical gender.<ref name="stan">{{cite encyclopedia|url=http://plato.stanford.edu/entries/sophists/#Pro|title=The Sophists (Stanford Encyclopedia of Philosophy)|encyclopedia=[[Stanford Encyclopedia of Philosophy]]|access-date=2012-05-01}}</ref><ref>Aristotle 1407b [https://www.perseus.tufts.edu/hopper/text?doc=Perseus%3Atext%3A1999.01.0059%3Abekker%20page%3D1407b Greek from Tufts U., with decipherment tools], [http://perseus.uchicago.edu/perseus-cgi/citequery3.pl?dbname=GreekFeb2011&query=Arist.%20Rh.%201407b&getid=1 English and Greek from U. Chicago] both in the Perseus Digital Library. The page is from Rhetoric, Book III, Chapter 5.</ref>

The titles of his books, such as ''Technique of Eristics'' (''Technē Eristikōn'', literally "Practice of Wranglings"— 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 [[Ancient Olympic Games|Olympic games]].<ref name="stan" />

[[Eusebius]] quoting [[Aristocles of Messene]] says that Protagoras was a member of a line of philosophy that began with [[Xenophanes]] and culminated in [[Pyrrhonism]].<ref>[[Eusebius]], ''[[Praeparatio Evangelica]]'' Chapter XVII.</ref>

===Relativism===
{{Rhetoric}}Protagoras also said that on any matter, there are two arguments (''logoi'') opposed to one another. Consequently, he may have been the author of ''[[Dissoi logoi]]'', an ancient Sophistic text on such opposing arguments.<ref>Gera, D.L. Two Thought Experiments in the ''Dissoi Logoi''. ''The American Journal of Philology''121(1): 24.</ref> According to [[Aristotle]], Protagoras was criticized for having claimed "to make the weaker argument stronger".<ref>''ton hēttō logon kreittō poiein''</ref><ref name=stan />

Protagoras is credited with the philosophy of [[relativism]], which he discussed in his lost work, ''Truth'' (also known as ''Refutations'').<ref name=poster2005 /><ref>{{cite web |last=Mattey |first=G.J. |title=Protagoras on Truth |url=http://hume.ucdavis.edu/mattey/phi021/protag.html |access-date=22 October 2013}}</ref> Although knowledge of Protagoras' position is limited, his relativism is inferred from one of his most famous statements: "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."<ref>{{cite book |last=Bostock |first=D |title=Plato's Theaetetus |year=1988 |location=Oxford}}</ref><ref>This quotation is restated in Plato's ''[[Theaetetus (dialogue)|Theaetetus]]'' at [https://www.perseus.tufts.edu/cgi-bin/ptext?lookup=Plat.+Theaet.+152a 152a]. [[Sextus Empiricus]] gives a direct quotation in ''Adv. math.'' 7.60: πάντων χρημάτων μέτρον ἐστὶν ἄνθρωπος, τῶν μὲν ὄντων ὡς ἔστιν, τῶν δὲ οὐκ ὄντων ὡς οὐκ ἔστιν. ''Man'' is the traditional translation for the Greek word ''anthrōpos'' (''human being, person''), representing a general statement about human beings.</ref>

Protagoras appears to have meant that each individual is the measure of how things are perceived by that individual. Therefore, things are, or are not, true according to how the individual perceives them. For example, Person X may believe that the weather is cold, whereas Person Y may believe that the weather is hot. According to the philosophy of Protagoras, there is no absolute evaluation of the nature of a temperature because the evaluation will be relative to who is perceiving it. Therefore, to Person X, the weather is cold, whereas to Person Y, the weather is hot. This philosophy implies that there are no absolute "truths". The truth, according to Protagoras, is relative, and differs according to each individual.<ref name=poster2005>{{cite encyclopedia |last=Poster |first=Carol |title=Protagoras |url=http://www.iep.utm.edu/protagor/ |encyclopedia=Internet Encyclopedia of Philosophy |orig-year=2002 |year=2005 |access-date=22 October 2013}}</ref>

[[Plato]] ascribes relativism to Protagoras and uses his character [[Socrates]] as a foil for his own commitment to objective and transcendent realities and values. Plato ascribes to Protagoras an early form of what [[John Daniel Wild|John Wild]] categorized as [[phenomenalism]].<ref>[[John Daniel Wild|John Wild]], "[https://www.jstor.org/stable/2103131 On the Nature and Aims of Phenomenology]," ''Philosophy and Phenomenological Research'' 3 (1942), p. 88: "Phenomenalism is as old as Protagoras."</ref> That being an assertion that something that is, or appears for a single individual, is true or real for that individual. However, as described in Plato's ''[[Theaetetus (dialogue)|Theaetetus]]'', Protagoras's views allow that some views may result from an ill body or mind. He stressed that although all views may appear equally true, and perhaps, should be equally respected, they certainly are not of equal gravity. One view may be useful and advantageous to the person who has it, while the perception of another may prove harmful. Hence, Protagoras believed that the sophist was there to teach the student how to discriminate between them, i.e., to teach [[arete|virtue]].

Both Plato and Aristotle argue against some of Protagoras's claims regarding relativity; however, they argue that the concept provides Protagoras with too convenient an exemption from his own theory and that relativism is true for him yet false for those who do not believe it. They claim that by asserting that truth is relative, Protagoras then could say that whatever further theory he proposed ''must'' be true.<ref>{{cite book |last=Lee |first=Mi-Kyoung |title=Epistemology after Protagoras: Responses to relativism in Plato, Aristotle |date=2005 |publisher=Oxford University Press |location=Oxford |isbn=0-19-926222-5 |url=https://books.google.com/books?id=i-dZyzjOqBoC&q=protagoras+relativism&pg=PR11}}</ref>

===Agnosticism===
Protagoras was a proponent of either [[agnosticism]] or, as [[Tim Whitmarsh]] claims, [[atheism]], on the grounds that since he held that if something is not able to be known it does not exist.<ref>[[Tim Whitmarsh]], ''Battling the Gods'', Alfred A. Knopf, 2015, pp. 88–89.</ref> Reportedly, in Protagoras's lost work, ''On the Gods'', he wrote: "Concerning the gods, I have no means of knowing whether they exist or not, nor of what sort they may be, because of the obscurity of the subject, and the brevity of human life."<ref>περἰ μἐν θεῶν οὐκ ἔχω εἰδέναι, οὔθ᾽ ὡς εἰσὶν οὔθ᾽ ὡς οὐκ εἰσιν οὔθ ὁποῖoί τινες ἰδέαν· πολλὰ γὰρ τὰ κωλύοντά με εἰδέναι, ἥ τε ἀδηλότης καὶ βραχὺς ὤν ὁ βίος ἀνθρώπου.</ref><!--English translation corrected: nor--><ref>[[DK numbering|DK]] 80B4.</ref><ref>[http://www.iep.utm.edu/p/protagor.htm The Internet Encyclopedia of Philosophy - Protagoras ({{circa|490 BCE|420 BCE}})], Accessed: October 6, 2008. "While the pious might wish to look to the gods to provide absolute moral guidance in the relativistic universe of the Sophistic Enlightenment, that certainty also was cast into doubt by philosophic and sophistic thinkers, who pointed out the absurdity and immorality of the conventional epic accounts of the gods. Protagoras' prose treatise about the gods began "Concerning the gods, I have no means of knowing whether they exist or not or of what sort they may be. Many things prevent knowledge including the obscurity of the subject and the brevity of human life".</ref>

According to [[Diogenes Laërtius]], the outspoken, agnostic position taken by Protagoras aroused anger, causing the Athenians to expel him from the city, and all copies of his book were collected and burned in the marketplace. The deliberate destruction of his works is also mentioned by [[Cicero]].<ref>Cicero, ''De Natura Deorum'', 1.23.6.</ref> The classicist [[John Burnet (classicist)|John Burnet]] doubts this account, however, as both Diogenes Laërtius and Cicero wrote hundreds of years later and as no such persecution of Protagoras is mentioned by contemporaries who make extensive references to this philosopher.<ref>John Burnet, "Greek Philosophy: From Thales to Plato", 1914.</ref> Burnet notes that even if some copies of the Protagoras books were burned, enough of them survived to be known and discussed in the following century.

===Spectrum of topics===

Nonetheless, very few fragments from Protagoras have survived, although he is known to have written several different works: ''Antilogiae'' and ''Truth''. The latter is cited by Plato, and was known alternatively as, ''The Throws'' (a wrestling term referring to the attempt to floor an opponent). It began with the "Man is the measure" (ἄνθρωπος μέτρον) pronouncement. According to Diogenes Laërtius other books by Protagoras include: ''On the Gods'', ''Art of Eristics'', ''Imperative'', ''On Ambition'', ''On Incorrect Human Actions'', ''On Those in Hades'', ''On Sciences'', ''On Virtues'', ''On the Original State of Things'' and ''Trial over a Fee''.<ref name=stan />

==See also==
* [[Anthropocentrism]]
* [[Paradox of the Court]]

==Notes==
{{Reflist}}

==References==
*[[W. K. C. Guthrie|Guthrie, W. K. C.]], ''The Sophists''. New York: Cambridge University Press (May 27, 1977). {{ISBN|0-521-09666-9}}.
*{{cite book|last1=Lee|first1=Mi-Kyoung|title=Epistemology after Protagoras: responses to relativism in Plato, Aristotle, and Democritus|url=https://archive.org/details/epistemologyafte0000leem|access-date=September 22, 2016|date=2005|isbn=978-0-19-926222-9|url-access=registration}}
*van Ophuijsen, J.M., van Raalte, M., Stork, P., ''Protagoras of Abdera: The Man, His Measure''. Brill, 2013. {{ISBN|978-90-04-25120-5}} (hardback); {{ISBN|978-90-04-25124-3}} (e-book)
*Bartlett, R., "Sophistry and Political Philosophy: Protagoras' Challenge to Socrates". Univ. of Chicago, 2016. {{ISBN|978-0-226-39428-2}} (hardback)

==External links==
* {{wikiquote-inline}}
* {{cite LotEP |chapter=Protagoras}}
* {{Cite EB1911|wstitle=Protagoras |short=x}}
* {{Sep entry|protagoras|Protagoras|Mauro Bonazzi}}
* {{cite IEP |url-id=protagor |title=Protagoras |last=Poster |first=Carol}}

{{Sophists}}
{{Greek schools of philosophy}}
{{Ancient Greece topics}}

{{Authority control}}

[[Category:490s BC births]]
[[Category:420s BC deaths]]
[[Category:5th-century BC Greek philosophers]]
[[Category:Abderites]]
[[Category:Ancient Greek epistemologists]]
[[Category:Ancient Greek ethicists]]
[[Category:Ancient Greek rhetoricians]]
[[Category:Philosophy writers]]
[[Category:Sophists]]
[[Category:Rhetoric theorists]]