Protagoras and the Fourteenth‐Century Invention of Epistemological Relativism

Abstract

When contemporary writers consider the history of relativism, more often than not, they simply gloss over the entire medieval period, suggesting that the absolute (and absolutely accepted) claims of the Catholic Church during this period blocked the development of any consideration of relativized notions of truth, morals, and ethics. This is an astounding oversight considering the attention that medieval writers themselves paid to the problem in everything from economic treatises to pastoral manuals. Indeed, a comparison between thirteenth‐ and fourteenth‐century commentaries on book IV of Aristotle's Metaphysics (where the Philosopher discusses the opinions of the pre‐Socratic thinker Protagoras) reveals the development of proto‐relativized epistemologies. The turn towards relativized conceptions of knowledge had everything to do with the possibility of visual error and the recognition that visual evidence is often susceptible to multiple incompatible explanations. This article charts the development of this discovery in the commentaries of Siger of Brabant (ca. 1240–1280s), Thomas Aquinas (ca. 1225–1274), and Nicholas of Autrecourt (ca. 1299–ca. 1369), as well as in the writings of Nicole Oresme (ca. 1323–1382).

Keywords:

• Protagoras (ca. 490–420 BCE)
• Nicholas of Autrecourt (ca. 1299–ca. 1369)
• Siger of Brabant (ca. 1240–1280s)
• Oresme, Nicole (ca. 1323–1382)
• Relativism
• Vision

Notes

1. Nicole Oresme, Le Livre du ciel et du monde, ed. Albert D. Menut and Alexander J. Denomy, trans. Albert D. Menut (Madison: University of Wisconsin, 1968), 522, lines 61–64: “Item, je suppose que mouvement l<ocal ne> peut estre sensiblement apparceu fors en tant comme l'en apparçoit un corps soy avoir autrement ou resgart d'autre corps.”

2. Oresme, Le Livre, 522, lines 76–79: “Et il appert ou quart livre de La Perspective de Witelo que l'en ne apparçoit mouvement fors telement comme l'en apparçoit. i. corps soy avoir autrement ou resgart d'un autre.”

3. Oresme, Le Livre, 522, lines 87–91: “Et samblablement, se un homme estoit ou ciel, posé que il soit meu de mouvement journal, et cest homme qui est porté aveques le ciel voiot clerement la terre et distin<c>teement les mons, les vaulz, fleuves, villes et chastiaulz, il lui sambleroit que la terre <fust> meue de mouvement journal, aussi comme il samble du ciel a nous qui sommes en terre.”

4. Oresme, Le Livre, 536, lines 344–49: “Or appert donques comment l'en ne peut monstrer par quelcunque experience que le ciel soit meu de mouvement journal, car comment que soit, posé que il soit ainsi meu et la terre non ou la terre meue et le ciel non, se un ouyl estoit ou ciel et il voiṣt clerement la terre, elle sembleroit meue, et se le ouyl estoit en terre, le ciel sembleroit meu.”

5. Oresme, Le Livre, 536–38, lines 355–64: “Mais consideré tout ce que dit est, l'en pourroit par ce croire que la terre est ainsi meue et le ciel non, et n'est pas evidant du contraire; et toutevoies, ce semble de prime face autant ou plus contre raison naturelle comme sont les articles de nostre foy ou touz ou pluseurs. Et ainsi ce que je ay dit par esbatement en ceste maniere peut aler valoir a confuter et reprendre ceulz qui voudroient nostre foy par raysons impugner.” In interpreting this passage, I follow Pierre Souffrin, “Oresme, Buridan, et le mouvement derotation diurne de la terre ou des cieux,” in Bernard Ribémont, ed., Terres Médiévales (Paris: Editions Klincksieck, 1993), 284–88. Edward Grant, “Nicole Oresme on Certitude in Science and Pseudo‐Science,” in P. Souffrin and A. Ph. Segonds, eds., Nicole Oresme: Tradition et innovation chez un intellectuel du XIVe siècle (Paris: Les Belles Lettres, 1988), 39–40, reads this as an example of Oresme's use of “reason to confound reason.”

6. For examples, see John Hedley Brooke, Science and Theology: Some Historical Perspectives (Cambridge: Cambridge University Press, 1991), 58–63, and Robert Pasnau, “Human Nature,” in A. S. McGrade, ed., The Cambridge Companion to Medieval Philosophy (Cambridge: Cambridge University Press, 2003), 220–21.

7. Dan Burton, ed. and trans., Nicole Oresme's De visione stellarum: A Critical Edition (Leiden: Brill, 2007), 64, draws this conclusion concerning Oresme's arguments in On Seeing the Stars.

8. See, for example, Dominik Perler, “Could God Deceive Us? Skeptical Hypotheses in Late Medieval Epistemology,” in H. Lagerlund, ed., Skepticism in Medieval Philosophy (Leiden: Brill, forthcoming) and Christophe Grellard, “Scepticism, Demonstration and the Infinite Regress Argument (Nicholas of Autrecourt and John Buridan),” Vivarium 45 (2007): 328–29. Antoine Côté, “Siger and the Skeptic,” The Review of Metaphysics LX, no. 2 (2006): 308, makes a similar point specifically with respect to Siger of Brabant.

9. The contemporary literature on this topic is both vast and contentious. For a general overview see, Maria Baghramian, Relativism (London: Routledge, 2004) and the various essays collected in Jack W. Meiland and Michael Krausz, eds., Relativism: Cognitive and Moral (Notre Dame, IN: Notre Dame University Press, 1982), and Michael Krausz, ed., Relativism: Interpretation and Confrontation (Notre Dame, IN: Notre Dame University Press, 1989).

10. Baghramian, Relativism, 51–52.

11. On the anachronism of interpreting Scholastic debates in terms of skepticism, see Richard A. Lee, Jr., “Being Skeptical about Skepticism: Methodological Themes concerning Ockham's Alleged Skepticism,” Vivarium 39, no. 1 (2001): 1–19.

12. Nicholas of Autrecourt, Exigit ordo, ed. J. Reginald O'Donnell, Mediaeval Studies 1 (1939): 228: “Consequenter tractandum est de hoc problemate an omne illud quod apparet sit; et omne illud quod apparet esse verum sit verum.” Julius Weinberg is one of the few modern commentators to comment that this expression derives from Protagoras (Julius Weinberg, Nicolaus of Autrecourt: A Study in 14th‐Century Thought [New York: Greenwood, 1969], 176–84).

13. Siger of Brabant, Quaestiones in metaphysicam, ed. William Dunphy (Louvain‐la‐Neuve: Éditions de l'Institut Supérieur de Philosophie, 1981), liber IV, quaestio 28, commentum, 220: “… quod omne quod apparet est verum.”

14. Aristotle, Metaphysica: Recensio et translatio Guillelmi de Moerbeka, Gudrun Vuillemin‐Diem, ed., Aristoteles Latinus XXV 3.2 (Leiden: Brill, 1995), lib. IV, 1006a 1–2: “Sunt autem quidam qui, ut diximus, dicebant contingere idem esse et non esse et existimare ita.”

15. Aristotle, Metaphysica lib. IV [5], 1009a6–1009a10: “Est autem et ab eadem opinione Protagore ratio, et necesse similiter ipsas ambas aut esse aut non esse. Nam si que videntur omnia sunt vera et apparentia, necesse omnia simul vera et falsa esse. Multi namque contraria invicem existimant, et non eadem opinantes sibi ipsis mentiri putant; quare necesse idem esse et non esse.”

16. See Mi‐Kyoung Lee, Epistemology after Protagoras: Responses to Relativism in Plato, Aristotle and Democritus (Oxford: Clarendon Press, 2005), 21–29.

17. Miles Burnyeat, “Protagoras and Self‐Refutation in Later Greek Philosophy,” The Philosophical Review 85, no. 1 (1976): 44–45, argues that while Plato presents Protagoras as a relativist about truth, Aristotle and Sextus Empiricus present him as a subjectivist or infallibilist “whose view is that every judgment is true simpliciter – true absolutely, not merely true for the person whose judgment it is.” Gail Fine, “Protagorean Relativisms,” Proceedings of the Boston Area Colloquium in Ancient Philosophy (1996): 238–43, emphasizing the Heracleitean ontological underpinnings that Plato supplies for Protagoras's thesis, argues that Plato also presents Protagoras as an infallibilist. Richard Bett, “The Sophists and Relativism,” Phronesis XXXIV, no. 2 (1989): 168, contends that “relativism, in the deep sense, is largely foreign to Greek philosophy as a whole,” while leaving open the very faint possibility that Protagoras may have been the exception.

18. Chris Swoyer, “True For,” in Meiland and Krause, eds., Relativism, 84–89, presents a nice overview of these issues.

19. Siger, Quaestiones, IV, q. 28, commentum, 220, lines 2–5: “Consequenter ponit Philosophus quasdam rationes, quae movebant quosdam ad dicendum quod idem simul est et non est, ibi: Est autem et ab eadem. Et primo dicit quod idem est hoc opinari et opinari quod omne quod apparet est verum: convertuntur enim inter se, sicut determinat Philosophus in littera.”

20. Thomas Aquinas, Metaphysicorum aristotelis, ed. M.‐R. Cathala (Rome: Marietti, 1950), IV, lectio ix, 661.

21. Siger, Quaestiones, lib. IV, quaes. 28, commentum, 221, lines 40–44: “Et similiter eidem de eadem re in diversis temporibus contraria videntur; eadem autem ratione qua uni apparet verum, et alii, quia aequaliter credit suae opinioni quae ex rebus causatur; quare vel neutri apparet verum vel utrique; inconveniens autem est quod neutri, et ideo utrique apparet verum; quare omnia putata, vera sunt.” Also, Thomas, Metaphysicorum, IV, lectio xi, 669.

22. Thomas, Metaphysicorum, IV, lectio v, 593: “Antiqui enim non opinabantur aliquam substantiam esse praeter substantiam corpoream mobilem de qua physicus tractat. Et ideo creditum est, quod soli determinent de tota natura, et per consequens de ente; et ita etiam de primis principiis quae sunt simul consideranda cum ente.”

23. Thomas, Metaphysicorum, IV, lectio viii, 637: “Primo ad opinionem Protagorae, qui dicebat quod quicquid alicui videtur, hoc totum est verum; quia si alicui videtur quod homo non sit triremes, non erit triremes; et si alteri videtur quod sit triremes, erit triremes; et sic erunt contradictoria vera.”

24. Siger, Quaestiones IV, q. 28, commentum 220–21, lines 14–19: “Ponit igitur rationem quae movet ad ponendum contradictoria esse in eodem, dicens quod hoc habuit ortum ex sensibilibus: quia enim videbant ex eodem fieri contraria et contradictoria, ex non ente autem non fit aliquid, quare utrumque oppositorum prius fuit in eo ex quo fiebat, et sic idem esset contradictoria.”

25. Siger, Quaestiones, lib. IV, quaes. 28. commentum, 221 and quaes. 31, 224–26.

26. Thomas, In metaphysicorum, lib. IV, lectio x, 667, 182.

27. Siger, Quaestiones, lib. IV, quaes. 34, solutio, 229, lines 57–61: “Unde intelligendum quod duo sunt quae possunt inducere ad credendum quod omne quod apparet verum sit. Si quis enim dubitet in iudiciis contrariis sensuum cui magis est credendum et videatur sibi quod neutri magis quam alteri, immo quod utrique pari ratione, potest moveri ad opinandum quod omne quod apparet sensui verum est.”

28. Siger, Quaestiones, lib. IV, quaes. 34, solutio, 229, lines 64–72: “Aliud est quod idem potest inducere, ut si quis, in omni iudicio sensus quod ipsum iudicium sensus de sensibili sic se habeat, quaereret aliam rationem iudicantem, non posset certe iudicare veritatem in rebus, quia, si non esset aliquid primo certum, non esset aliquid aliud certum; et ideo, si non sit certum primo quod hoc comprehenditur gustu sit sapor dulcis vel amarus, nihil est certum, et ideo omne quod apparet sensui verum est; sicut autem quia alicui sensui de aliquo est magis credendum quam alii, et ideo non oportet quaerere omnium semper aliam rationem, ideo est aliquid verum determinate.”

29. Siger, Quaestiones, lib. IV, quaes. 34, solutio, 231, lines 17–18: “Antiqui enim dixerunt intellectum et sensum esse idem, et similiter omne quod apparet sensui esse verum.”

30. Thomas, In metaphysicorum, lib. IV, lectio xii, 672: “Cognitio autem sensus fit per quamdam alterationem sensus ad sensibilia: et ita quod sensus aliquid sentiat, provenit ex impressione rei sensibilis in sensum. Et sic semper cognitio sensus respondet naturae rei sensibilis, ut videtur. Oportet igitur; secundum eos, quod illud, quod videtur secundum sensum, sit de necessitate verum. Cum autem coniunxerimus quod omnis cognitio est sensitiva, sequitur quod omne quod alicui apparet quocumque modo, sit verum.”

31. Siger, Quaestiones, lib. IV, quaes. 34, solutio, 230.

32. Siger, Quaestiones, lib. IV, quaes. 34, solutio, 230, lines 83–87: “Et cum arguitur secundo quod, si magis est credendum uni sensui quam alii, oportet quod iudicium sensus sit certum et quod sensus semper eodem modo iudicet, dicendum quod verum est secundum quod magis est credendum, et hoc est de sensibili proprio: de isto enim semper eodem iudicat.”

33. Siger, Quaestiones, lib. IV, quaes. 35, solutio, 234, lines 45–46: “Est autem intelligendum quod, in eis quae sunt per se nota, non potest quis mente dubitare, licet voce contingat dicere oppositum.”

34. Siger, Quaestiones, lib. IV, quaes. 35, solutio, 234, lines 53–55 : “Tunc sic arguitur: in quo nullus potest dubitare, non est quaerendum aliud notificans ipsum; sed in hoc quod quis videt album, quin sit album non dubitat; quare aliud notificans ad hoc non est quaerendum.” For an overview of Siger's realist commitments and how they relate to these issues, see Côté, “Siger and the Skeptics,” 316–20.

35. Siger, Quaestiones, lib. IV, quaes. 34, 230.

36. Siger, Quaestiones, lib. IV, quaes. 34, 231, lines 29–32: “Philosophus enim in X huius dicit quod sapiens est mensura rerum, et consequenter ibi dicit quod magis res sunt mensura sapientis: non enim sic se habet res quia sapiens sic iudicat, sed sapiens sic iudicat quia res sic se habet.”

37. Nicholas, Exigit ordo, 228, lines 5–12: “Consequenter tractandum est de hoc prolemate an omne illud quod apparet sit; et omne illud quod apparet esse verum sit verum. Circa quod considerandum est quod dicens: omne quod apparet est verum, saltem loquendo de apparentia quae attenditur secundum sensus exteriores, sufficit satis quod sciat respondere ad contrarium; nam regula generaliter posita non debet modificari nec restringi nisi sit necessitas cogens ad modificandum, et ita sufficit quod sic dicens sustineat onus respondentis; sufficit enim quantum ad faciendum inclinari magis intellectum isti conclusioni quam oppositae.” On Nicholas's life and the status of his surviving works, see Zenon Kaluza, Nicolas d'Autrécourt: ami de la verité, in Histoire littéraire de la France, Vol. 42, fasc. 1 (1995). For a very different account of both Aristotle's critique and Nicholas's defense of Protagoras, see Christophe Grellard, Croire et Savoir: Les principes de la connaisance selon Nicolas d'Autrécourt (Paris: Librairie Philosophique J. Vrin, 2005), 43–55.

38. Nicholas, Exigit ordo, 182–85, has a fair amount to say about the wise man or, at least, the conditions under which a person can stand up against majority opinion.

39. Nicholas, Exigit ordo, 185.

40. The standard work on the history of these debates during the later thirteenth through the fourteenth century is Katherine Tachau, Vision and Certitude in the Age of Ockham: Optics, Epistemology and the Foundations of Semantics, 1250–1345 (Leiden: Brill, 1988).

41. Thomas, In metaphysicorum, lib. IV, lectio XIV, 705: “Si omnes apparens est verum, nec aliquid est verum nisi ex hoc ipso quod est apparens sensui, sequetur quod nihil est nisi inquantum sensibile est in actu. Sed si solum sic aliquid est, scilicet inquantum est sensibile, sequetur quod nihil sit si non erunt sensus. Et per consequens si non erunt animata vel animalia. Hoc autem est impossibile.”

42. Thomas, In metaphysicorum, lib. IV, lectio XV, 716: “Et ex hoc sequitur hoc inconveniens quod nihil sit, nec fiat, nullo opinante. Si autem hoc falsum est, qui multa sunt et fiunt de quibus nulla est opinio vel cognitio, sicut quae sunt in profundo maris vel in visceribus terrae, manifestum est quod non omnia sunt ad aliquid, idest ad opinionem et sensum. Et ita non omne apparens est verum.”

43. John of Jandun, Quaestiones in duodecim libros metaphysicae (Venice, 1553; rprt. Frankfurt, 1966), lib. IV, quaes. XXII, 57r: “Item, si hoc esset, tunc omnia entia essent entia rationis & haberent esse ab anima, & patet consequential quia quod formaliter refertur ad aliquid non habet esse formale preter illud ut patet relativis, quod est falsum, quia aliqua entia sunt naturalia.”

44. Thomas, In metaphysicorum, lib. IV, lectio XV, 713.

45. John of Jandun, Quaestiones, lib. IV, quaes. XXI, 57r: “Dicendum quod cognitivo sensitive potest esse certa & determinate respectu proprii obiecti concurrentibus debitis conditionibus ut vult Themistius, 2 De anima, ut quando organum est dispositum & medium, & debita distantia obiecti, & similiter intellective potest esse certa, quia cognoscit res per causas & species, quo representant res certitudinaliter & infallibiliter, & dato quod aliquando sensus erret, tamen intellectus non quia est virtus superior & certior, & potest corrigere & rectificare phantasmata & sensata dum modo habeat principium aliquale excitativum in operatione sua, & promotivum.”

46. John Buridan, Kommentar zur Aristotelischen Metaphysik, lib. II, q. 1 (rprt. Frankfurt, 1964), 9r. On Buridan's reliabilism, see Jack Zupko, Portrait of a Fourteenth‐Century Arts Master (Notre Dame, IN: Notre Dame University Press, 2003), 197. Christoph Flüeler, “From Oral Lecture to Written Commentaries: John Buridan's Commentaries on Aristotle's Metaphysics,” in Sten Ebbesen and Russell L. Friedman, eds., Medieval Analyses in Language and Cognition (Copenhagen: C. A. Reitzels Forlag, 1999), 497–521, demonstrates that Buridan's first commentaries on the Metaphysics date from the 1340s.

47. Nicholas, Exigit ordo, 228, lines 37–42: “Contra: illa responsio non est bona quae tollit ab intellectu certitudinem super rebus; ista est hujusmodi quia non est magis impossibile quod evidentia de convenienti dispositione stet cum non esse, ita quod sit ultimate evidens quod potentia sit bene disposita, et tamen non sit quam quod sit ultimate evidens rubedinem esse et tamen non sit rubedo.”

48. Siger of Brabant, Quaestiones, lib. IV, quaes. 35, 233, lines 25–27: “Item, ration per quam probat Aristoteles quod non omnium est ratio quaerenda non valet: dicit enim quod, si omnium est ratio, tunc nihil est scitum per rationem et demonstrationem …”

49. Nicholas, Exigit ordo, 231, lines 12–17: “… nam a sic dicente quaero duo: primo unde est certus quod illa requiruntur; non poterit dare pro vero medio nisi apparentiam vel lumen suum, et ita negando propositum concedet propositum. Item quaero ab eo qui dicit se esse certum, an sciat quod illa tria concurrunt, quod potentia sua sit bene disposita etc. Non potest praetendere verum medium nisi quia sic apparet sibi.”

50. Nicholas, Exigit ordo, 228, lines 21–25: “Arguo sic: de omni eo intellectus est certus quod est sibi evidens et ultimate evidens vel ipsi secundum actum sensus. Nunc de omni eo quod apparet proprie, quails apparentia est solum in actu sensuum exteriorum, est hujusmodi, alias non diceretur proprie apparere.”

51. Nicholas, Exigit ordo, 229, lines 9–12: “Verum est ergo si diceremus: omne quod judicatur verum esse verum, vel cui intellectus assentit, sequeretur illud quod dicis; sed sic non dicimus, sed solum est sermo noster de actua apparentiae.”

52. Nicholas, Exigit ordo, 231, lines 3–7: “Et dicamus hanc regulam per alia verba: omnis actus dicendi formatus in pleno lumine, quantum lumen potest esse plenum apud hominem, est verus; nam omnis actus mensuratus secundum suam veram regulam est verus; sed actus dicendi formatus in pleno luimine est mensuratus secundum veram regulam, scilicet lumen plenum.”

53. Nicholas, Exigit ordo, 229, lines 42–44: “Si enim essent aequaliter clarae, vel deberet dicere sibi esse nihil certum, vel concedere esse verum illud quod apparet esse verum in utraque apparentia.”

54. Nicholas, Exigit ordo, 230, lines 41–49: “Igitur istam est verum, quod nullus potest dicere se esse certum de aliquo nisi habeat lumen illius vel alicujus ad quod consequatur necessario. Et propter istam propositionem alias dixi quod nullus potest dicere quod in corpore praeter trinum dimensionem sit aliqua realitas per modum fundamenti sicut dicunt illi qui ponunt quantitatem distingui a substantia materiali. Et ratio est quia nec illa realitas habet aliquod lumen penes intellectum in quo experiatur ejus existentia; non enim vidimus eam vel audivimus neque ex visionibus nostris vel aliter quocumque modo sensatis potest concludi inexistentia talis realitatis ut alias dictum est.”

55. On Nicholas's atomism, see Weinberg, Nicolaus of Autrecourt, 140–48.

56. Nicholas, Exigit ordo, 228, lines 18–20: “Dico igitur si aliqua certitudo nobis insit de rebus quod probabile est quod omne illud quod apparet esse sit, et quod omne illud quod apparet esse verum sit verum.”

57. On Nicholas's metaphysical probability see, Dallas G. Denery II, Seeing and Being Seen in the Later Medieval World (Cambridge: Cambridge University Press, 2005), 149–55.

58. Nicholas, Exigit ordo, 204, lines 1–6: “Has igitur rationes induxi ut probabiles ad conclusionem; certum est quod conclusio haec non potest probari per explicationem conceptuum terminorum conclusionis, quae media dicuntur causae formalis, ita quod sciens per talia dicitur scire per causam formalem; et explices quantumcumque vis, de conceptibus explicitis non concludes affirmativam nec negativam. Ergo in hujus rei consideratione oportuit me recurrere ad causam finalem …”

59. Nicholas, Exigit ordo, 184.

60. Nicholas, Exigit ordo, 204, lines 10–15: “Ista sunt sic dicta secundum apparentia naturalia quibus nunc participamus; scio vero quod veritas est et fides Catholica hoc tenet quod non omnes res sunt aeternae nec huic rei videor contradicere quia solum dico quod ista conclusio secundum apparentia naturalia quibus nunc participamus est probabilior oppostia.”

61. J. M. M. H. Thijssen, “The Quest for Certain Knowledge in the Fourteenth Century: Nicholas of Autrecourt against the Academics,” in Juha Sihvola, ed., Ancient Scepticism and the Sceptical Tradition (Helsinki: The Philosophical Society of Finland, 2000), 199–200, also notes the centrality of epistemology to Nicholas's philosophy. On the tradition of privileging metaphysics over epistemology, see Jack Zupko, “Sacred Doctrine, Secular Practice: Theology and Philosophy in the Faculty of Arts at Paris, 1325–1400,” in J. A. Aertsen and A. Speer, eds., Was ist Philosophie im Mittelalter? (Berlin: W. de Gruyter, 1998), 656–66, and for Thomas Aquinas, Scott MacDonald, “Theory of Knowledge,” in Cambridge Companion to Aquinas, ed. Norman Kretzmann and Eleonore Stump (Cambridge: Cambridge University Press, 1993), 160.

62. For a useful assessment of reasons for and against Quine's thesis, see Gordon C. F. Bearn, “The Horizon of Reason,” in Krausz, Relativism, 205–31. Baghramian, Relativism, 212–44, provides an overview of conceptual and scheme‐content relativism.

63. On the Renaissance reception of Protagoras, see Charles Trinkaus, “Protagoras in the Renaissance: An Exploration,” in Edmund Mahoney, ed., Philosophy and Humanism: Essays in Honor of Paul Oskar Kristeller (New York: Columbia University Press, 1976), 190–213.

64. Oresme, Le Livre, 324–55.

65. Joel Kaye, Economy and Nature in the Fourteenth Century (Cambridge: Cambridge University Press, 1998), 231–46.