In his medical work, as reflected by his name, tradition maintains that he belonged to the Empiric school in which Pyrrhonism was popular. However, at least twice in his writings, Sextus seems to place himself closer to the Methodic school.

Little is known about Sextus Empiricus. He likely lived in Alexandria, Rome, or Athens. The Suda, a 10th-century Byzantine encyclopedia, states that he was the same person as Sextus of Chaeronea,[2] but this identification is commonly doubted.[3]

Writings

Diogenes Laërtius[4] and the Suda[5] report that Sextus Empiricus wrote ten books on Pyrrhonism. The Suda also says Sextus wrote a book Ethica. Sextus Empiricus's three surviving works are the Outlines of Pyrrhonism (Πυῤῥώνειοι ὑποτυπώσεις, Pyrrhōneioi hypotypōseis, thus commonly abbreviated PH), and two distinct works preserved under the same title, Adversus Mathematicos (Πρὸς μαθηματικούς, Pros mathematikous , commonly abbreviated "AM" and known as Against Those in the Disciplines, or Against the Mathematicians). Adversus Mathematicos is incomplete as the text references parts that are not in the surviving text. Adversus Mathematicos also includes mentions of three other works which did not survive:

Medical Commentaries (AD I 202)
Empirical Commentaries (AM I 62)
Commentaries on the Soul which includes a discussion of the Pythagoreans' metaphysical theory of numbers (AD IV 284) and shows that the soul is nothing (AM VI 55)[6]

The surviving first six books of Adversus Mathematicos are commonly known as Against the Professors. Each book also has a traditional title;[7] although none of these titles except Pros mathematikous and Pyrrhōneioi hypotypōseis are found in the manuscripts. The supposed general title of this work is Skeptical Treatises' (Σκεπτικὰ Ὑπομνήματα /Skeptika Hypomnēmata).[8]
Book English title Greek title
I Against the Grammarians Πρὸς γραμματικούς / Pros grammatikous
II Against the Rhetoricians Πρὸς ῥητορικούς / Pros rhetorikous
III Against the Geometers Πρὸς γεωμετρικούς / Pros geometrikous
IV Against the Arithmeticians Πρὸς ἀριθμητικούς / Pros arithmetikous
V Against the Astrologers Πρὸς ἀστρολόγους / Pros astrologous
VI Against the Musicians Πρὸς μουσικούς / Pros mousikous

Adversus Mathematicos I–VI is sometimes distinguished from Adversus Mathematicos VII–XI by using another title, Against the Dogmatists ( Πρὸς δογματικούς, Pros dogmatikous) and then the remaining books are numbered as I–II, III–IV, and V, despite the fact that it is also commonly inferred that the beginning of such a separate work is missing and it is not known how many books might have preceded the extant books.
Book English title Greek title
VII–VIII Against the Logicians Πρὸς λογικούς / Pros logikous
IX–X Against the Physicists Πρὸς φυσικούς / Pros Physikous
XI Against the Ethicists Πρὸς ἠθικούς / Pros Ethikous

The equanimity of the philosopher Pyrrho of Elis in the storm

Philosophy
Main article: Pyrrhonism

Sextus Empiricus raised concerns which applied to all types of knowledge. He doubted the validity of induction[9] long before its best known critic David Hume, and raised the regress argument against all forms of reasoning:

Those who claim for themselves to judge the truth are bound to possess a criterion of truth. This criterion, then, either is without a judge's approval or has been approved. But if it is without approval, whence comes it that it is truthworthy? For no matter of dispute is to be trusted without judging. And, if it has been approved, that which approves it, in turn, either has been approved or has not been approved, and so on ad infinitum.[10]

Because of these and other barriers to acquiring true beliefs, Sextus Empiricus advises[11] that we should suspend judgment about virtually all beliefs; that is to say, we should neither affirm any belief as true nor deny any belief as false. This view is known as Pyrrhonian skepticism, as distinguished from Academic skepticism, as practiced by Carneades, which, according to Sextus, denies knowledge altogether. Sextus did not deny the possibility of knowledge. He criticizes the Academic skeptic's claim that nothing is knowable as being an affirmative belief. Instead, Sextus advocates simply giving up belief; in other words, suspending judgment (epoché) about whether or not anything is knowable.[12] Only by suspending judgment can we attain a state of ataraxia (roughly, 'peace of mind'). Sextus did not think such a general suspension of judgment to be impractical, since we may live without any beliefs, acting by habit.

Sextus allowed that we might affirm claims about our experience (e.g., reports about our feelings or sensations). That is, for some claim X that I feel or perceive, it could be true to say "it seems to me now that X." However, he pointed out that this does not imply any objective knowledge of external reality. Though I might know that the honey I eat at a certain moment tastes sweet to me, this is merely a subjective judgment, and as such may not tell me anything true about the honey itself.

Interpretations of Sextus's philosophy along the above lines have been advocated by scholars such as Myles Burnyeat,[13] Jonathan Barnes,[14] and Benson Mates.[15]

Michael Frede, however, defends a different interpretation,[16] according to which Sextus does allow beliefs, so long as they are not derived by reason, philosophy or speculation; a skeptic may, for example, accept common opinions in the skeptic's society. The important difference between the skeptic and the dogmatist is that the skeptic does not hold his beliefs as a result of rigorous philosophical investigation. In Against the Ethicists, Sextus in fact directly says that "the Skeptic does not conduct his life according to philosophical theory (so far as regards this he is inactive), but as regards the non-philosophical regulation of life he is capable of desiring some things and avoiding others." (XI, 165). Thus, on this interpretation (and as per Sextus' own words), the skeptic may well entertain the belief that God does or does not exist or that virtue is good. But he will not believe that such claims are true on the basis of reasons since, as far as the skeptic is aware, no reason for assenting to such claims has yet been shown to be "any more" credible than the reasons for their denial. (XIX)

It must also be remembered that by "belief" (i.e., dogma) Sextus means "assent to something non-evident [ἄδηλος, adēlos]" (PH I, 16). And by "non-evident" he means things which lie beyond appearances (i.e., phantasiai), and thus are beyond proof or disproof, such as the existence and/or nature of causality, time, motion, or even proof itself. Thus, the skeptic will, for example, believe the proposition that "Dion is in the room" if sense-data and ordinary reasoning led to the emergence of such a belief. On the other hand, if he were to "strongly" assert that Dion was "really" in the room, then he may be met with opposing arguments of equal psychological force against the self-same proposition and experience mental disquietude as a result. Thus, the Pyrrhonian does not assent to the proposition "Dion is in the room" in a dogmatic way as that would purport to describe a non-evident reality which lies beyond the "appearance" [φαινόμενον, phainomenon] of Dion being in the room. The Skeptic simply goes along with the appearance just as "a child is persuaded by...his teacher." (PH I, 229). It is for this reason then that Sextus says the Skeptic lives undogmatically in accordance with appearances and also according to a "fourfold regimine of life" which includes the guidance of nature, compulsion of pathe (feelings), laws and customs, and instruction in arts and crafts. The Skeptic follows this course of life while suspending judgment concerning the ultimate truth of the non-evident matters debated in philosophy and the sciences (PH I, 17). Thus, the Pyrrhonist achieves ataraxia not by casting certain judgments about appearances but rather through his refined ability to "oppose appearances to judgments" such that he is "brought firstly to a state of mental suspense and next to ataraxia.'" (IV, 8)

The ten modes of Pyrrhonism
Main article: The ten modes of Aenesidemus

Pyrrhonism is more of a mental attitude or therapy than a theory. It involves setting things in opposition and owing to the equipollence of the objects and reasons, one suspends judgement. "We oppose either appearances to appearances or objects of thought to objects of thought or alternando."[17] The ten modes induce suspension of judgement and in turn a state of mental suspense followed by ataraxia. If ever one is in a position in which they are unable to refute a theory, Pyrrhonists reply "Just as, before the birth of the founder of the School to which you belong, the theory it holds was not as yet apparent as a sound theory, although it was really in existence, so likewise it is possible that the opposite theory to that which you now propound is already really existent, though not yet apparent to us, so that we ought not as yet to yield assent to this theory which at the moment seems to be valid."[18] These ten modes or tropes were originally listed by Aenesidemus (see The ten modes of Aenesidemus).

"The same impressions are not produced by the same objects owing to the differences in animals."[19]
The same impressions are not produced by the same objects owing to the differences among human beings.[20]
The same impressions are not produced by the same objects owing to the differences among the senses.[21]
Owing to the "circumstances, conditions or dispositions," the same objects appear different. These are "states that are natural or unnatural, with waking or sleeping, with conditions due to age, motion or rest, hatred or love, emptiness or fullness, drunkenness or soberness, predispositions, confidence or fear, grief or joy."[22]
"Based on positions, distances, and locations; for owing to each of these the same objects appear different." For example, "the same porch when viewed from one of its corners appears curtailed, but viewed from the middle symmetrical on all sides; and the same ship seems at a distance to be small and stationary, but from close at hand large and in motion ; and the same tower from a distance appears round but from a near point quadrangular." [23]
“We deduce that since no object strikes us entirely by itself, but along with something else, it may perhaps be possible to say what the mixture compounded out of the external object and the thing perceived with it is like, but we would not be able to say what the external object is like by itself."[24]
"Based, as we said, on the quantity and constitution of the underlying objects, meaning generally by "constitution" the manner of composition." So, for example, goat horn appears black when intact and appears white when ground up. Snow appears white when frozen and translucent as a liquid.[25]
"Since all things appear relative, we will suspend judgment about what things exist absolutely and really existent.[26] Do things which exist "differentially" as opposed to those things that have a distinct existence of their own, differ from relative things or not? If they do not differ, then they too are relative; but if they differ, then, since everything which differs is relative to something..., things which exist absolutely are relative."[27]
"Based on constancy or rarity of occurrence." The sun is more amazing than a comet, but because we see and feel the warmth of the sun daily and the comet rarely, the latter commands our attention.[28]
"There is a Tenth Mode, which is mainly concerned with Ethics, being based on rules of conduct, habits, laws, legendary beliefs, and dogmatic conceptions."[29]

Superordinate to these ten modes stand three other modes:

I: that based on the subject who judges (modes 1, 2, 3 & 4).
II: that based on the object judged (modes 7 & 10).
III: that based on both subject who judges and object judged (modes 5, 6, 8 & 9)

Superordinate to these three modes is the mode of relation.[30]
Similarity with Madhyamaka Buddhism
Main article: Similarities between Pyrrhonism and Buddhism

Because of the high degree of similarity between the surviving works of Sextus Empiricus and those of the Madhyamaka Buddhist philosopher, Nagarjuna[31] Thomas McEvilley[32] and Matthew Neale[33][34] suspect that Nagarjuna and Sextus Empiricus were referencing some of the same earlier Pyrrhonist texts in developing their works.
Legacy

An influential Latin translation of Sextus's Outlines was published by Henricus Stephanus in Geneva in 1562,[35] and this was followed by a complete Latin Sextus with Gentian Hervet as translator in 1569.[36] Petrus and Jacobus Chouet published the Greek text for the first time in 1621. Stephanus did not publish it with his Latin translation either in 1562 or in 1569, nor was it published in the reprint of the latter in 1619.

Sextus's Outlines were widely read in Europe during the 16th, 17th and 18th centuries, and had a profound effect on Michel de Montaigne, David Hume, and Georg Wilhelm Friedrich Hegel, among many others. Another source for the circulation of Sextus's ideas was Pierre Bayle's Dictionary. The legacy of Pyrrhonism is described in Richard Popkin's The History of Skepticism from Erasmus to Descartes and High Road to Pyrrhonism. The transmission of Sextus's manuscripts through antiquity and the Middle Ages is reconstructed by Luciano Floridi's Sextus Empiricus, The Recovery and Transmission of Pyrrhonism (Oxford: Oxford University Press, 2002). Since the Renaissance French philosophy has been continuously influenced by Sextus: Montaigne in the 16th century, Descartes, Blaise Pascal, Pierre-Daniel Huet and François de La Mothe Le Vayer in the 17th century, many of the "Philosophes," and in recent times controversial figures such as Michel Onfray, in a direct line of filiation between Sextus' radical skepticism and secular or even radical atheism.[37]

Sextus is the earliest known source for the proverb "Slowly grinds the mill of the gods, but it grinds fine", alluded to in Longfellow's poem "Retribution".[38]
Works
Translations

Old complete translation in four volumes

Sextus Empiricus, Sextus Empiricus I: Outlines of Pyrrhonism. R.G. Bury (trans.) (Cambridge, Massachusetts: Harvard University Press, 1933/2000). ISBN 0-674-99301-2
Sextus Empiricus, Sextus Empiricus II: Against the Logicians. R.G. Bury (trans.) (Cambridge, Massachusetts: Harvard University Press, 1935/1997). ISBN 0-674-99321-7
Sextus Empiricus, Sextus Empiricus III: Against the Physicists, Against the Ethicists. R.G. Bury (trans.) Cambridge, Massachusetts: Harvard University Press, 1936/1997. ISBN 0-674-99344-6
Sextus Empiricus, Sextus Empiricus IV: Against the Professors. R.G. Bury (trans.) (Cambridge, Massachusetts: Harvard University Press, 1949/2000). ISBN 0-674-99420-5

New partial translations

Sextus Empiricus, Against the Grammarians (Adversos Mathematicos I) David Blank (trans.) Oxford: Clarendon Press, 1998. ISBN 0-19-824470-3
Sextus Empiricus, Against those in the Disciplines (Adversos Mathematicos I-VI). Richard Bett (trans.) (New York: Oxford University Press 2018). ISBN 9780198712701
Sextus Empiricus, Against the Logicians. (Adversus Mathematicos VII and VIII). Richard Bett (trans.) Cambridge: Cambridge University Press, 2005. ISBN 0-521-53195-0
Sextus Empiricus, Against the Physicists (Adversus Mathematicos IX and X). Richard Bett (trans.) Cambridge: Cambridge University Press, 2012. ISBN 0-521-51391-X
Sextus Empiricus, Against the Ethicists (Adversus Mathematicos XI). Richard Bett (trans.) (Oxford: Clarendon Press, 2000). ISBN 0-19-825097-5
Sextus Empiricus, Outlines of Scepticism. Julia Annas and Jonathan Barnes (trans.) (Cambridge: Cambridge University Press, 2nd ed. 2000). ISBN 0-521-77809-3
Sextus Empiricus, The Skeptic Way: Sextus Empiricus's Outlines of Pyrrhonism. Benson Mates (trans.) Oxford: Oxford University Press, 1996. ISBN 0-19-509213-9
Sextus Empiricus, Selections from the Major Writings on Skepticism Man and God. Sanford G. Etheridge (trans.) Indianapolis: Hackett, 1985. ISBN 0-87220-006-X

French translations

Sextus Empiricus, Contre les Professeurs (the first six treatises), Greek text and French Translation, under the editorship of Pierre Pellegrin (Paris: Seuil-Points, 2002). ISBN 2-02-048521-4
Sextus Empirucis, Esquisses Pyrrhoniennes, Greek text and French Translation, under the editorship of Pierre Pellegrin (Paris: Seuil-Points, 1997).

Old editions

Sexti Empirici Adversus mathematicos, hoc est, adversus eos qui profitentur disciplinas, Gentiano Herveto Aurelio interprete, Parisiis, M. Javenem, 1569 (Vicifons).

See also

Pyrrhonism
Problem of induction
Philosophical skepticism
Skepticism
Protagoras
Sextus of Chaeronea
Dissoi Logoi

Notes

Berry, Jessica (2011). Nietzsche and the Ancient Skeptical Tradition. Oxford University Press. p. 230. ISBN 978-0-19-536842-0.
Suda, Sextos σ 235.
Luciano Floridi Sextus Empiricus: The Transmission and Recovery of Pyrrhonism 2002 ISBN 0195146719 pp 3–7.
Diogenes Laërtius Lives of Eminent Philosophers "Life of Timon" Book IX Chapter 12 Section 116 [1]
Suda, Sextos σ 235.
Machuca, Diego Sextus Empiricus : his outlook, works, and legacy 2008 p. 35 [2]
Stanford Encyclopedia of Philosophy. "Sextus Empiricus". Retrieved 29 May 2015.
Sara Ahbel-Rappe, Rachana Kamtekar (2009). A Companion to Socrates. ISBN 9781405192606.
Sextus Empiricus. Outlines of Pyrrhonism trans. R.G. Bury (Loeb edn) (London: W. Heinemann, 1933), p. 283.
Sextus Empiricus. Against the Logicians trans. R.G. Bury (Loeb edn) (London: W. Heinemann, 1935) p. 179
The extent to which a skeptic can hold beliefs as well as the kinds of beliefs a skeptic can have is a matter of scholarly dispute.
See PH I.3, I.8, I.198; cf. J. Barnes, "Introduction", xix ff., in Sextus Empiricus, Outlines of Scepticism. Julia Annas and Jonathan Barnes (transl.) (Cambridge: Cambridge University Press, 2000).
Burnyeat, M., "Can The Sceptic Live His Scepticism" in Myles Burnyeat and Michael Frede (ed.), The Original Sceptics: A Controversy (Hackett, 1997): 25–57. Cf. Burnyeat, M., "The Sceptic in His Place and Time", ibid., 92–126.
Barnes, J., "The Beliefs of a Pyrrhonist" in Myles Burnyeat and Michael Frede (ed.), The Original Sceptics: A Controversy (Hackett, 1997): 58–91.
Mates, B. The Skeptic Way (Oxford UP, 1996).
Frede, M., "The Sceptic's Beliefs" in Myles Burnyeat and Michael Frede (ed.), The Original Sceptics: A Controversy (Hackett, 1997): 1–24. Cf. Frede, M., "The Skeptic's Two Kinds of Assent and the Question of the Possibility of Knowledge", ibid., 127–152.
Sextus Empiricus, Outlines of Pyrrhonism, Trans. R.G. Bury, Harvard University Press, Cambridge, Massachusetts, 1933, p. 23
Sextus Empiricus, Outlines of Pyrrhonism, Translated by R.G. Bury, Harvard University Press, Cambridge, Massachusetts, 1933, p. 23
Sextus Empiricus, Outlines of Pyrrhonism, Trans. R.G. Bury, Harvard University Press, Cambridge, Massachusetts, 1933, p. 27
Sextus Empiricus, Outlines of Pyrrhonism, Trans. R.G. Bury, Harvard University Press, Cambridge, Massachusetts, 1933, p. 47
Sextus Empiricus, Outlines of Pyrrhonism, Trans. R.G. Bury, Harvard University Press, Cambridge, Massachusetts, 1933, p. 55
Sextus Empiricus, Outlines of Pyrrhonism, Trans. R.G. Bury, Harvard University Press, Cambridge, Massachusetts, 1933, p.61
Sextus Empiricus, Outlines of Pyrrhonism, Trans. R.G. Bury, Harvard University Press, Cambridge, Massachusetts, 1933, p.69-71
Sextus Empiricus, Outlines of Pyrrhonism, Trans. R.G. Bury, Harvard University Press, Cambridge, Massachusetts, 1933, p.73
Sextus Empiricus, Outlines of Pyrrhonism, Trans. R.G. Bury, Harvard University Press, Cambridge, Massachusetts, 1933, p.77
Sextus Empiricus, Outlines of Pyrrhonism, Trans. R.G. Bury, Harvard University Press, Cambridge, Massachusetts, 1933, p. 79
Sextus Empiricus, Outlines of Pyrrhonism, Trans. R.G. Bury, Harvard University Press, Cambridge, Massachusetts, 1933, p. 81
Sextus Empiricus, Outlines of Pyrrhonism, Trans. R.G. Bury, Harvard University Press, Cambridge, Massachusetts, 1933, p. 83
Sextus Empiricus, Outlines of Pyrrhonism, Trans. R.G. Bury, Harvard University Press, Cambridge, Massachusetts, 1933, p. 85
Sextus Empiricus, Outlines of Pyrrhonism, Trans. R.G. Bury, Harvard University Press, Cambridge, Massachusetts, 1933, pp. 25–27
Adrian Kuzminski, Pyrrhonism: How the Ancient Greeks Reinvented Buddhism 2008
Thomas McEvilley, The Shape of Ancient Thought 2002 pp499-505
[3]
[4]
Bican Şahin, [Toleration: The Liberal Virtue], Lexington Books, 2010, p. 18.
Richard Popkin (editor), History of Western Philosophy (1998) p. 330.
Recent Greek-French edition of Sextus's works by Pierre Pellegrin, with an upbeat commentary. Paris: Seuil-Points, 2002.

D.L. Blank, trans., Sextus Empiricus: Against the Grammarians (Adversus Mathematicos I), p. 311, ISBN 0-19-824470-3

Bibliography

Annas, Julia and Barnes, Jonathan, The Modes of Scepticism: Ancient Texts and Modern Interpretations, Cambridge: Cambridge University Press, 1985. ISBN 0-521-27644-6
Bailey, Alan, Sextus Empiricus and Pyrrhonean scepticism, Oxford: Oxford University Press, 2002. ISBN 0-19-823852-5
Bett, Richard, Pyrrho, His Antecedents, and His Legacy, Oxford: Oxford University Press, 2000. ISBN 0-19-925661-6
Breker, Christian, Einführender Kommentar zu Sextus Empiricus' "Grundriss der pyrrhonischen Skepsis", Mainz, 2011: electr. publication, University of Mainz. available online (comment on Sextus Empiricus’ “Outlines of Pyrrhonism" in German language)
Brennan, Tad, Ethics and Epistemology in Sextus Empiricus, London: Garland, 1999. ISBN 0-8153-3659-4
Brochard, Victor, Les Sceptiques grecs (1887) reprint Paris: Librairie générale française, 2002.
Burnyeat, Myles and Frede, Michael The Original Sceptics: A Controversy, Hackett: Indianapolis, 1997. ISBN 0-87220-347-6
Floridi, Luciano, Sextus Empiricus: the Transmission and Recovery of Pyrrhonism, Oxford: Oxford University Press, 2002. ISBN 0-19-514671-9
Hankinson, R.J., The Sceptics, London: Routledge, 1998. ISBN 0-415-18446-0
Hookway, C., Scepticism, London: Routledge, 1992. ISBN 0-415-08764-3
Jourdain, Charles, Sextus Empiricus et la philosophie scholastique, Paris: Paul Dupont, 1858.
Janáček, Karel, Sexti Empirici indices, Firenze: Olschki, 2000.
Janáček, Karel, Studien zu Sextus Empiricus, Diogenes Laertius und zur pyrrhonischen Skepsis. Hrsg. v. Jan Janda / Filip Karfík (= Beiträge zur Altertumskunde; Bd. 249), Berlin: de Gruyter 2008.
Mates, Benson, The Skeptic Way: Sextus Empiricus's Outlines of Pyrrhonism, Oxford: Oxford University Press, 1996.
Pappenheim Eugen, Lebensverhältnisse des Sextus Empiricus, Berlin, Nauck, 1875.
Perin, Casey, The Demands of Reason: An Essay on Pyrrhonian Scepticism, Oxford: Oxford University Press, 2010.
Popkin, Richard, The History of Scepticism: From Savonarola to Bayle, Oxford: Oxford University Press, 2003. ISBN 0-19-510768-3
Vazquez, Daniel, Reason in Check: the Skepticism of Sextus Empiricus, Hermathena, 186, 2009, pp. 43–57.

External links
Wikiquote has quotations related to: Sextus Empiricus

Against the Mathematicians (at the Stoic Therapy eLibrary)
Wikisource logo Works written by or about Sextus Empiricus at Wikisource
Excerpts from the "Outlines of Pyrrhonism" by Sextus Empiricus
Morison, Benjamin. "Sextus Empiricus". In Zalta, Edward N. (ed.). Stanford Encyclopedia of Philosophy.
Sextus Empiricus and Greek Scepticism (at Project Gutenberg; includes translation of first book of the Pyrrhonic Sketches)
The complete works of Sextus Empiricus in Greek (at Google Books).
Sexti Empirici opera recensuit Hermannus Mutschmann, voll. 2, Lipsiae in aedibus B. G. Teubneri, 1912.

See also

• Philosophical skepticism
  
• Solipsism
  
• Pyrrho
  
• Problem of the criterion
  

Sextus Empiricus and Greek Scepticism