Keywords
Plato
Theaetetus
epistemology
politics
How to Cite
Abstract
In the Theaetetus, which seeks a definition of knowledge, the first definition of Theaetetus, namely that ‘knowledge is perception’, is easily refuted without the need to refer to Protagoras. But for Plato the refutation of Protagoras is a goal in itself, and he devotes almost half the dialogue to this task. He argues that the doctrine of homo mensura amounts to saying that ‘all judgements are true’ and, using his ‘most exquisite argument’, he claims to prove that it is self-refuting. As many scholars have recognised, this alleged demonstration depends on the arbitrary dropping of the relativistic qualifier that specifies ‘for whom’ a given judgement is true. Plato does not justify the disappearance of the qualifier, but rather tries to disguise it. Indeed, Protagoras has an epistemological conception that is opposed to Plato’s theory of knowledge and that is fundamental to the logical justification of the political conceptions set out in the Republic. For Plato, therefore, the refutation of Protagoras’ doctrine of homo mensura is an imperative ethical requirement. He is not too demanding in his choice of arguments: he does not seek rigour in argumentation, only persuasive effectiveness – more than two millennia of interpretations have proved him right.
References
Ambuel, D., 2015, Turtles All the Way Down. On Plato’s Theaetetus, a Commentary and Translation, Sankt Augustin.
Annas, J., 1981, An Introduction to Plato’s Republic, Oxford.
Aronadio F., 2016, L’Aisthesis e le strategie argomentative di Platone nel Teeteto, Napoli.
Arruzza, C., Nikulin, D. (eds.), 2016, Philosophy and Political Power in Antiquity, Leiden–Boston. DOI: https://doi.org/10.1163/9789004324626
Barnes, J., 1979b, The Presocratic Philosophers, London (2nd ed. 1982).
Beresford, A., 2013, “Fangs, Feathers, & Fairness: Protagoras on the origins of right and wrong,” in: Ophuijsen, Raalte, Stork 2013, pp. 139–162. DOI: https://doi.org/10.1163/9789004251243_008
Berkel T. A. van, 2013, “Made to Measure: Protagoras’ Metron,” in: Ophuijsen, Raalte Stork 2013, pp. 37–67. DOI: https://doi.org/10.1163/9789004251243_004
Brancacci, A., 2011, “La ‘dottrina riservata’ di Protagora (Plat. ‘Theaet’ 152c7–e1),” Méthexis 24, pp. 87–108. DOI: https://doi.org/10.1163/24680974-90000580
Brisson, L., 1975, “Le mythe de Protagoras: Essai d’analyse structural,” Quaderni Urbinati di Cultura Classica 20, pp. 7–37. DOI: https://doi.org/10.2307/20537736
Burnyeat, M. F., 1976, “Protagoras and self-refutation in Plato’s Theaetetus,” The Philosophical Review 85, pp. 172–195. DOI: https://doi.org/10.2307/2183729
Burnyeat, M. F., 1990, The Theaetetus of Plato, Indianapolis.
Bury, R. G. (transl.), 1935, Sextus Empiricus, Against the Logicians, Cambridge–London. DOI: https://doi.org/10.4159/DLCL.sextus_empiricus-against_logicians.1935
Calabi, F., 1998, “La nobile menzogna,” in: Vegetti 1998, pp. 445–457.
Calenda, G., 2020, “Epistemological Relevance of Parmenides’ Ontology,” Anais de Filosofia Clássica 14, pp. 96–120. DOI: https://doi.org/10.47661/afcl.v14i27.38779
Calenda, G., 2022, La condanna di Socrate. Audiatur et altera pars, Baden-Baden. DOI: https://doi.org/10.5771/9783985720255
Capizzi, A., 1955, Protagora. Le testimonianze e i frammenti, Firenze.
Casertano, G., 2002, Il Teeteto di Platone: struttura e problematiche, Napoli.
Casertano, G., 2002a, “Le definizioni socratiche di Episteme,” in: Casertano 2002, pp. 87–117.
Chappell, T. D. J., 2004, Reading Plato’s Theaetetus, Sankt Augustin.
Cornford, F. M., 1935/57, Plato’s Theory of Knowledge. The Theaetetus and the Sophist. New York (Mineola 2003).
Decleva Caizzi, F., 2002, “Da Protagora al discorso ‘Maggiore’ (Tht. 171d5–172c1),” in: Casertano 2002, pp. 63–86.
El Murr, D. (ed.), La mesure du savoir. Études sur le Théétète de Platon, Paris.
Erginel, M. M., 2009, “Relativism and Self-Refutation in the Theaetetus,” Oxford Studies in Ancient Philosophy 37, pp. 1–45. DOI: https://doi.org/10.1093/oso/9780199575565.003.0001
Ferrari, F. (cur.), 2011, Platone, Teeteto, Milano.
Ferrari, G. R. F. (ed.), 2000, Plato, The Republic, Cambridge.
Fine, G., 1998, “Plato’s Refutation of Protagoras in the Theaetetus,” Apeiron 31, pp. 201–234. DOI: https://doi.org/10.1515/APEIRON.1998.31.3.201
Fowler, H. N. (transl.), 1921, Plato in Twelve Volumes, Cambridge–London.
Gadamer, H.-G., 1978, Die Idee des Guten zwischen Plato und Aristoteles, Heidelberg (engl. transl. P. C. Smith, The Idea of the Good in Platonic-Aristotelian Philosophy, New Haven 1986).
Gavray, M.-A., 2013, “Comment ne pas interpréter un fragment philosophique. Le dialogue avec Protagoras dans le Théétète,” in: El Murr 2013, pp. 25–47. DOI: https://doi.org/10.4000/books.vrin.4547
Giorgini, G., 2016, “The Power of Speech: The Influence of the Sophists on Greek Politics,” Arruzza, Nikulin 2016, pp. 9–40. DOI: https://doi.org/10.1163/9789004324626_003
Grote, G., 1885–18883, Plato and the other companions of Sokrates. London.
Ioppolo, A. M. (cur.), 1999, Platone, Teeteto, Bari.
Kerferd, G. B. (ed.), 1981, The Sophists and Their Legacy, Wiesbaden.
Maguire, J. P., 1973, “Protagoras – Or Plato?,” Phronesis 18, pp. 115–138. DOI: https://doi.org/10.1163/156852873X00096
Maguire, J. P., 1977, “Protagoras… Or Plato? II. The ‘Protagoras’,” Phronesis 22, pp. 103–122. DOI: https://doi.org/10.1163/156852877X00029
Mandelbaum, M., 1979, “Subjective, Objective, and Conceptual Relativisms,” The Monist 62, pp. 403–428. DOI: https://doi.org/10.5840/monist197962433
Mansfeld, J., 1981, “Protagoras on Epistemological Obstacles and Persons,” in: Kerferd 1981, pp. 38–53.
McDowell, G. (ed.), 1973, Plato, Theaetetus, Oxford.
Mendelson, M., 2002, Many Sides: A Protagorean Approach to the Theory, Practice, and Pedagogy of Argument, Dondrecht. DOI: https://doi.org/10.1007/978-94-015-9890-3
Mondolfo, R., 1955, La comprensión del sujeto humano en la cultura antigua. Imán, Buenos Aires (Ital. transl. L. Bassi: La comprensione del soggetto umano nell’antichità classica, Firenze 1958; Milano 2012).
Ophuijsen, J. M. van, Raalte, M. Van, Stork, P. (eds.), 2013, Protagoras of Abdera. The Man, His Measure, Leiden–Boston.
Rossetti, L., 1990, “Sulla differenza tra il fenomenismo di Protagora e il fenomenismo scettico,” in: Voelke 1990, pp. 55–68.
Runciman, W. G., 1962, Plato’s Later Epistemology, Cambridge.
Sartori, F., Vegetti, M., Centrone, B. (cur.), 1997, Platone, La Repubblica, Bari.
Schiappa, E., 1991, Protagoras and Logos, Columbia.
Schiller, F. C. S., 1907, Studies in Humanism, London (Adamant Media 2005).
Schiller, F. C. S., 1908a, Plato or Protagoras?, Oxford.
Schiller, F. C. S., 1908b, “Plato or Protagoras?,” Mind 17, pp. 518–526. DOI: https://doi.org/10.1093/mind/XVII.4.518
Sedley, D., 2004, The Midwife of Platonism. Text and Subtext in Plato’s Theaetetus, Oxford. DOI: https://doi.org/10.1093/0199267030.001.0001
Vegetti, M. (cur.), 1998a, Platone, La Repubblica, Vol. II, Napoli
Vegetti, M. (cur.), 1998b, Platone, La Repubblica, Vol. III, Napoli.
Versényi, L.,1962), “Protagoras’ Man-Measure Fragment,” The American Journal of Philology 83, pp. 178–184. DOI: https://doi.org/10.2307/292215
Vlastos, G. (ed.), 1956, Plato, Indianapolis.
Voelke, A.-J. (ed.), 1991, Le scepticisme antique. Perspective historiques et systématiques, Lausanne.
Waterlow, S., 1977, “Protagoras and Inconsistency: Theaetetus 171a6–c7,” Archiv für Geschichte der Philosophie 59, pp. 19–39. DOI: https://doi.org/10.1515/agph.1977.59.1.19
Zilioli, U., 2007, Protagoras and the Challenge of Relativism. Plato’s Subtlest Enemy, London.
License
This work is licensed under a Creative Commons Attribution 4.0 International License.
Peitho provides immediate open access to its content on the principle that making research freely available to the public supports a greater global exchange of knowledge.