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the Skeptic Carneades

The Skeptics — a group that in its extreme forms avoided all activity and human contact by going into the desert — argued it was impossible to be sure about anything. According to the Stanford Encyclopedia of Philosophy: “The Greek word skepsis means investigation. By calling themselves skeptics, the ancient skeptics thus describe themselves as investigators. They also call themselves ‘those who suspend’, thereby signaling that their investigations lead them to suspension of judgment. They do not put forward theories, and they do not deny that knowledge can be found. At its core, ancient skepticism is a way of life devoted to inquiry. It is as much concerned with belief as with knowledge. As long as knowledge has not been attained, the skeptics aim not to affirm anything. This gives rise to their most controversial ambition: a life without belief. Ancient skepticism is, for the most part, a phenomenon of Post-Classical, Hellenistic philosophy. The Academic and Pyrrhonian movements begin roughly in the third century B.C., and end with Sextus Empiricus in the second century CE. [Stanford Encyclopedia of Philosophy, 2010; updated 2014]

According to the Internet Encyclopedia of Philosophy: “Although all skeptics in some way cast doubt on our ability to gain knowledge of the world, the term "skeptic" actually covers a wide range of attitudes and positions. There are skeptical elements in the views of many Greek philosophers, but the term "ancient skeptic" is generally applied either to a member of Plato's Academy during its skeptical period (c. 273 B.C.E to 1st century B.C.E.) or to a follower of Pyrrho (c. 365 to 270 B.C.E.). Pyrrhonian skepticism flourished from Aenesidemus' revival (1st century B.C.E.) to Sextus Empiricus, who lived sometime in the 2nd or 3rd centuries C.E. Thus the two main varieties of ancient skepticism: Academic and Pyrrhonian. [Source: Internet Encyclopedia of Philosophy (IEP) ]

“The term "skeptic" derives from a Greek noun, skepsis, which means examination, inquiry, consideration. What leads most skeptics to begin to examine and then eventually to be at a loss as to what one should believe, if anything, is the fact of widespread and seemingly endless disagreement regarding issues of fundamental importance. Many of the arguments of the ancient skeptics were developed in response to the positive views of their contemporaries, especially the Stoics and Epicureans, but these arguments have been highly influential for subsequent philosophers and will continue to be of great interest as long as there is widespread disagreement regarding important philosophical issues.

“Nearly every variety of ancient skepticism includes a thesis about our epistemic limitations and a thesis about suspending judgment. The two most frequently made objections to skepticism target these theses. The first is that the skeptic's commitment to our epistemic limitations is inconsistent. He cannot consistently claim to know, for example, that knowledge is not possible; neither can he consistently claim that we should suspend judgment regarding all matters insofar as this claim is itself a judgment. Either such claims will refute themselves, since they fall under their own scope, or the skeptic will have to make an apparently arbitrary exemption. The second sort of objection is that the alleged epistemic limitations and/or the suggestion that we should suspend judgment would make life unlivable. For, the business of day-to-day life requires that we make choices and this requires making judgments. Similarly, one might point out that our apparent success in interacting with the world and each other entails that we must know some things. Some responses by ancient skeptics to these objections are considered in the following discussion.

“The distinction between Academic and Pyrrhonian skepticism continues to be a controversial topic. In the Second Century C.E., the Roman author Aulus Gellius already refers to this as an old question treated by many Greek writers (Attic Nights 11.5.6, see Striker [1981/1996]). The biggest obstacle to correctly making this distinction is that it is misleading to describe Academic and Pyrrhonian skepticism as distinctly unified views in the first place since different Academics and Pyrrhonists seem to have understood their skepticisms in different ways. So even though the terms Academic and Pyrrhonian are appropriate insofar as there are clear lines of transmission and development of skeptical views that unify each, we should not expect to find a simple account of the distinction between the two.

Websites on Ancient Greece and Rome: Internet Encyclopedia of Philosophy; Stanford Encyclopedia of Philosophy; Internet Ancient History Sourcebook: Greece ; Internet Ancient History Sourcebook: Hellenistic World ; BBC Ancient Greeks; Canadian Museum of History; Perseus Project - Tufts University; ; ;; British Museum; Illustrated Greek History, Dr. Janice Siegel, Department of Classics, Hampden–Sydney College, Virginia ; The Greeks: Crucible of Civilization ; Oxford Classical Art Research Center: The Beazley Archive ;; Metropolitan Museum of Art; The Ancient City of Athens; The Internet Classics Archive ; Internet Ancient History Sourcebook: Rome ; Internet Ancient History Sourcebook: Late Antiquity ; Forum Romanum ; “Outlines of Roman History”; “The Private Life of the Romans”|; BBC Ancient Rome;
The Roman Empire in the 1st Century; The Internet Classics Archive ; Bryn Mawr Classical Review; De Imperatoribus Romanis: An Online Encyclopedia of Roman Emperors; Cambridge Classics External Gateway to Humanities Resources; Ancient Rome resources for students from the Courtenay Middle School Library ; History of ancient Rome OpenCourseWare from the University of Notre Dame / ; United Nations of Roma Victrix (UNRV) History

Academic Skepticism

According to the Internet Encyclopedia of Philosophy: “Following Plato's death in 347 B.C.E., his nephew Speusippus became head of the Academy. Next in line were Xenocrates, Polemo and Crates. The efforts of the Academics during this period were largely directed towards developing an orthodox Platonic metaphysics. When Crates died (c. 272 B.C.E.) Arcesilaus of Pitane (c. 318 to 243 B.C.E.) became the sixth head of the Academy. Another member of the Academy, Socratides, who was apparently in line for the position, stepped down in favor of Arcesilaus (Diogenes Laertius [DL] 4.32); so it seems he was held in high regard by his predecessors, at least at the time of his appointment. (See Long [1986] for discussion of the life of Arcesilaus.) [Source: Internet Encyclopedia of Philosophy (IEP) ]

“According to Diogenes Laertius, Arcesilaus was "the first to argue on both sides of a question, and the first to meddle with the traditional Platonic system [or: discourse, logos] and by means of question and answer, to make it more of a debating contest" (4.28, translation after R.D. Hicks). Diogenes is certainly wrong about Arcesilaus being the first to argue on both sides of a question. This was a long standing practice in Greek rhetoric commonly attributed to the Sophists. But Arcesilaus was responsible for turning Plato's Academy to a form of skepticism. This transition was probably supported by an innovative reading of Plato's books, which he possessed and held in high regard (DL 4.31).

“Diogenes' remark that Arcesilaus "meddled" with Plato's system and made it more of a debating contest indicates a critical attitude towards his innovations. Diogenes (or his source) apparently thought that Arcesilaus betrayed the spirit of Platonic philosophy by turning it to skepticism. Cicero, on the other hand, in an approving tone, reports that Arcesilaus revived the practice of Socrates, which he takes to be the same as Plato's.

“"[Socrates] was in the habit of drawing forth the opinions of those with whom he was arguing, in order to state his own view as a response to their answers. This practice was not kept up by his successors; but Arcesilaus revived it and prescribed that those who wanted to listen to him should not ask him questions but state their own opinions. When they had done so, he argued against them. But his listeners, so far as they could, would defend their own opinion" (de Finibus 2.2, translated by Long and Sedley, 68J, see also de Natura Deorum 1.11).

“Arcesilaus had (selectively) derived the lesson from Plato's dialogues that nothing can be known with certainty, either by the senses or by the mind (de Oratore 3.67, on the topic of Plato and Socrates as proto-skeptics, see Annas [1992], Shields [1994] and Woodruff [1986]). He even refused to accept this conclusion; thus he did not claim to know that nothing could be known (Academica 45).

Attack on the Stoics

According to the Internet Encyclopedia of Philosophy: “In general, the Stoics were the ideal target for the skeptics; for, their confidence in the areas of metaphysics, ethics and epistemology was supported by an elaborate and sophisticated set of arguments. And, the stronger the justification of some theory, the more impressive is its skeptical refutation. They were also an attractive target due to their prominence in the Hellenistic world. Arcesilaus especially targeted the founder of Stoicism, Zeno, for refutation. Zeno confidently claimed not only that knowledge is possible but that he had a correct account of what knowledge is, and he was willing to teach this to others. The foundation of this account is the notion of katalêpsis: a mental grasping of a sense impression that guarantees the truth of what is grasped. If one assents to the proposition associated with a kataleptic impression, i.e. if one experiences katalepsis, then the associated proposition cannot fail to be true. The Stoic sage, as the perfection and fulfillment of human nature, is the one who assents only to kataleptic impressions and thus is infallible. [Source: Internet Encyclopedia of Philosophy (IEP) ]

“Arcesilaus argued against the possibility of there being any sense-impressions which we could not be mistaken about. In doing so, he paved the way for future Academic attacks on Stoicism. To summarize the attack: for any sense-impression S, received by some observer A, of some existing object O, and which is a precise representation of O, we can imagine circumstances in which there is another sense-impression S', which comes either (i) from something other than O, or (ii) from something non-existent, and which is such that S' is indistinguishable from S to A. The first possibility (i) is illustrated by cases of indistinguishable twins, eggs, statues or imprints in wax made by the same ring (Lucullus 84-87). The second possibility (ii) is illustrated by the illusions of dreams and madness (Lucullus 88-91). On the strength of these examples, Arcesilaus apparently concluded that we may, in principle, be deceived about any sense-impression, and consequently that the Stoic account of empirical knowledge fails. For the Stoics were thorough-going empiricists and believed that sense-impressions lie at the foundation of all of our knowledge. So if we could not be certain of ever having grasped any sense-impression, then we cannot be certain of any of the more complex impressions of the world, including what strikes us as valuable. Thus, along with the failure to establish the possibility of katalepsis goes the failure to establish the possibility of Stoic wisdom (see Hankinson [1995], Annas [1990] and Frede [1983/1987] for detailed discussions of this epistemological debate).

Core Issues in Skepticism

According to the Stanford Encyclopedia of Philosophy: “The core concepts of ancient skepticism are belief, suspension of judgment, criterion of truth, appearances, and investigation. Important notions of modern skepticism such as knowledge, certainty, justified belief, and doubt play no or almost no role. This is not to say that the ancients would not engage with questions that figure in today’s philosophical discussions. Ancient debates address questions that today we associate with epistemology and philosophy of language, as well as with theory of action, rather than specifically with the contemporary topic of skepticism. They focus on the nature of belief, the way in which belief figures in our mental lives, and the relationship of belief to speech and action. [Stanford Encyclopedia of Philosophy, 2010; updated 2014]

“Pre-Socratic philosophers formulate—often in the context of revisionist metaphysical theories, which lead into epistemological discussions—such claims as “nothing is known” (Lee 2010). The firm assertion, as found in these philosophers’ works, that there is no knowledge can be turned against itself: does the proponent of “nothing is known” claim to know that nothing can be known (and if not, why assert it)? This question gives rise to a puzzle that remains at the heart of ancient debates about skepticism. Can the skeptics say anything meaningful about their philosophy without asserting anything about how things are (Bett 2013)? Skeptical writings have a peculiar format, one that comes with its own challenges: the skeptics aim to describe their philosophy tout court, as they practice it, without laying out any particular theories or doctrines. Skeptical ideas have been charged with a family of objections: they might be self-refuting, inconsistent, self-contradictory, and so on (Castagnoli 2010). Another line of objection is associated with Hume, namely that “nature is always too strong for principle.” As Hume puts it, “a Pyrrhonian cannot expect that his philosophy will have any constant influence on the mind” (part 2 of section 12, “Of the Academical or Sceptical Philosophy,” An Enquiry Concerning Human Understanding, London, 1748). It is one thing for skepticism to be coherent. It is another thing for it to be likely that anyone, no matter how much she rehearses skeptical arguments in her mind, will succeed in adhering to it (Johnson 2001), as ancient Pyrrhonist philosophers claimed to be able to do.

“Like later epistemologists, the ancient skeptics start from questions about knowledge. But discussion quickly turns to beliefs (Fine 2000). The Greek term translated here as belief, doxa, can also be translated as opinion. The root of doxa is dokein, seeming. In a belief, something seems so-and-so to someone. But there is also an element of judgment or acceptance. The relevant verb, doxazein, often means ‘to judge that something is so-and-so.’ Hellenistic discussions envisage three attitudes that cognizers take to impressions (how things seem to them): assent, rejection, and suspension of judgment (epochê).

“Suspension is a core element of skepticism: the skeptic suspends judgment. However, if this means that the skeptic forms no beliefs whatsoever, then skepticism may be a kind of cognitive suicide. Arguably, belief-formation is a basic feature of human cognitive activity. It is not clear whether one can lead an ordinary human life without belief, or indeed, ancient opponents of the skeptics say, whether one can even survive. Perhaps even the simplest actions, such as eating or leaving a room without running into a wall, involve beliefs (on the practical side of ancient skepticism, see Annas-Barnes 1985, 7; Burnyeat 1980). It is also hard to say whether someone who succeeded in not forming any beliefs could communicate with others, whether she could engage in philosophical investigation, or whether she could even think at all.

“The ancient skeptics are well aware of these objections. The most widely discussed charge is that they cannot act without belief (Apraxia Charge). In response, the skeptics describe their actions variously as guided by the plausible, the convincing, or by appearances. The notion of appearances gains great importance in Pyrrhonian skepticism, and poses difficult interpretive questions (Barney 1992). When something appears so-and-so to someone, does this for the skeptics involve some kind of judgment on her part? Or do they have in mind a purely phenomenal kind of appearing? The skeptical proposals (that the skeptic adheres to the plausible, the convincing, or to appearances) have in common their appeal to something less than full-fledged belief about how things are, while allowing something sufficient to generate and guide action.

Suspending Judgment and Dialectical Interpretation

Sextus Empiricus

According to the Internet Encyclopedia of Philosophy: “In response to this lack of knowledge (whether limited to the Stoic variety or knowledge in general), Arcesilaus claimed that we should suspend judgment. By arguing for and against every position that came up in discussion he presented equally weighty reasons on both sides of the issue and made it easier to accept neither side (Academica 45). Diogenes counts the suspension of judgment as another of Arcesilaus' innovations (DL 4.28) and refers to this as the reason he never wrote any books (4.32). Sextus Empiricus (Outlines of Pyrrhonism [generally referred to by the initials of the title in Greek, PH] 1.232) and Plutarch (Adversus Colotes 1120C) also attribute the suspension of judgment about everything to him. [Source: Internet Encyclopedia of Philosophy (IEP) ]

“Determining precisely what cognitive attitude Arcesilaus intended by "suspending judgment" is difficult, primarily because we only have second and third hand reports of his views (if indeed he endorsed any views, see Dialectical Interpretation below). To suspend judgment seems to mean not to accept a proposition as true, i.e. not to believe it. It follows that if one suspends judgment regarding p, then he should neither believe that p nor should he believe that not-p (for this will commit him to the truth of not-p). But if believing p just means believing that p is true, then suspending judgment regarding everything is the same as not believing anything. If Arcesilaus endorsed this, then he could not consistently believe either that nothing can be known or that one should consequently suspend judgment.

“One way around this problem is to adopt the dialectical interpretation (advanced by Couissin [1929]). According to this interpretation, Arcesilaus merely showed the Stoics that they didn't have an adequate account of knowledge, not that knowledge in general is impossible. In other words, knowledge will only turn out to be impossible if we define it as the Stoics do. Furthermore, he did not show that everyone should suspend judgment, but rather only those who accept certain Stoic premises. In particular, he argued that if we accept the Stoic view that the Sage never errs, and since katalepsis is not possible, then the Sage (and the rest of us insofar as we emulate the Sage) should never give our assent to anything. Thus the only way to achieve sagehood, i.e. to consistently avoid error, is to suspend judgment regarding everything and never risk being wrong (Lucullus 66-67, 76-78, see also Sextus Empiricus, Against the Logicians [generally referred to by the initial M, for the name of the larger work from which it comes,Adversus Mathematikos] 7.150-57). But the dialectical Arcesilaus himself neither agrees nor disagrees with this.

Practical Criterion: to Eulogon

According to the Internet Encyclopedia of Philosophy: “The biggest obstacle to the dialectical interpretation is Arcesilaus' practical criterion, to eulogon. Arcesilaus presented this criterion in response to the Stoic objection that if we were to suspend judgment regarding everything, then we would not be able to continue to engage in day to day activities. For, the Stoics thought, any deliberate action presupposes some assent, which is to say that belief is necessary for action. Thus if we eliminate belief we will eliminate action (Plutarch, Adversus Colotes 1122A-F, LS 69A). [Source: Internet Encyclopedia of Philosophy (IEP) ]

“Sextus remarks that inasmuch as it was necessary . . . to investigate also the conduct of life, which cannot, naturally, be directed without a criterion, upon which happiness-that is, the end of life-depends for its assurance, Arcesilaus asserts that he who suspends judgment about everything will regulate his inclinations and aversion and his actions in general by the rule of "the reasonable [to eulogon]," and by proceeding in accordance with this criterion he will act rightly; for happiness is attained by means of wisdom, and wisdom consists in right actions, and the right action is that which, when performed, possesses a reasonable justification. He, therefore, who attends to "the reasonable" will act rightly and be happy (M 7.158, translated by Bury).

“There is a good deal of Stoic technical terminology in this passage, including the term eulogon itself, and this may seem to support the dialectical interpretation. On this view, Arcesilaus is simply showing the Stoics both that their account of knowledge is not necessary for virtue, and that they nonetheless already have a perfectly acceptable epistemic substitute, to eulogon (see Striker [1980/1996]). But this raises the question, why would Arcesilaus make such a gift to his Stoic adversaries? It would be as if, Maconi's words, "Arcesilaus first knocked his opponent to the ground and then gave him a hand up again" (1988: 248). Such generosity would seem to be incompatible with the purely dialectical purpose of refutation. Similarly, if he had been arguing dialectically all along, there seems to be no good reason for him to respond to Stoic objections, for he was not presenting his own views in the first place. On the other hand, the proponent of the dialectical view could maintain that Arcesilaus has not done any favors to the Stoics by giving them the gift of to eulogon; rather, this "gift" may still be seen as a refutation of the Stoic view that a robust knowledge is necessary for virtue.

“An alternative to the dialectical view is to interpret to eulogon as Arcesilaus' own considered opinion regarding how one may live well in the absence of certainty. This view then encounters the earlier difficulty of explaining how it is consistent for Arcesilaus to endorse suspending judgment on all matters while at the same time believing that one may attain wisdom and happiness by adhering to his practical criterion. b. Carneades

“Arcesilaus was succeeded by Lacydes (c. 243 B.C.E.), and then Evander and Hegesinus in turn took over as heads of the Academy. Following Hegesinus, Carneades of Cyrene (c. 213 to 129 B.C.E.), perhaps the most illustrious of the skeptical Academics, took charge. Rather than merely responding to the dogmatic positions that were currently held as Arcesilaus did, Carneades developed a wider array of skeptical arguments against any possible dogmatic position, including some that were not being defended. He also elaborated a more detailed practical criterion, to pithanon. As was the case with Arcesilaus, he left nothing in writing, except for a few letters, which are no longer extant (DL 4.65).



Pyrrho (c. 360—c. 270 B.C.) a Greek philosopher from Elis, and founder of the Greek school of skepticism. According to the Internet Encyclopedia of Philosophy: “In his youth he practiced the art of painting, but passed over this for philosophy. He studied the writings of Democritus, became a disciple of Bryson, the son of Stilpo, and later a disciple of Anaxarchus. He took part in the Indian expedition of Alexander the Great, and met with philosophers of the Indus region. Back in Greece he was frustrated with the assertions of the Dogmatists (those who claimed to possess knowledge), and founded a new school in which he taught fallibilism, namely that every object of human knowledge involves uncertainty. Thus, he argued, it is impossible ever to arrive at the knowledge of truth (Diog. Laert, 58). It is related that he acted on his own principles, and carried his skepticism to such an extreme, that his friends were obliged to accompany him wherever he went, so he might not be run over by carriages or fall down precipices. It is likely, though, that these reports were invented by the Dogmatists whom he opposed. He spent a great part of his life in solitude, and was undisturbed by fear, or joy, or grief. He withstood bodily pain, and when in danger showed no sign of apprehension. In disputes he was known for his subtlety. Epicurus, though no friend to skepticism, admired Pyrrho because he recommended and practiced the kind of self-control that fostered tranquillity; this, for Epicurus, was the end of all physical and moral science. Pyrrho was so highly valued by his countrymen that they honored him with the office of chief priest and, out of respect for him, passed a decree by which all philosophers were made immune from taxation. He was an admirer of poets, particularly Homer, and frequently cited passages from his poems. After his death, the Athenians honored his memory with a statue, and a monument to him was erected in his own country. [Source: Internet Encyclopedia of Philosophy (IEP) ]

“Pyrrho left no writings, and we owe our knowledge of his thoughts to his disciple Timon of Phlius. His philosophy, in common with all post-Aristotelian systems, is purely practical in its outlook. Skepticism is not posited on account of its speculative interest, but only because Pyrrho sees in it the road to happiness, and the escape from the calamities of life. The proper course of the sage, said Pyrrho, is to ask himself three questions. Firstly we must ask what things are and how they are constituted. Secondly, we ask how we are related to these things. Thirdly, we ask what ought to be our attitude towards them. As to what things are, we can only answer that we know nothing. We only know how things appear to us, but of their inner substance we are ignorant. The same thing appears differently to different people, and therefore it is impossible to know which opinion is right. The diversity of opinion among the wise, as well as among the vulgar, proves this. To every assertion the contradictory assertion can be opposed with equally good grounds, and whatever my opinion, the contrary opinion is believed by somebody else who is quite as clever and competent to judge as I am. Opinion we may have, but certainty and knowledge are impossible. Hence our attitude to things (the third question), ought to be complete suspense of judgment. We can be certain of nothing, not even of the most trivial assertions. Therefore we ought never to make any positive statements on any subject. And the Pyrrhonists were careful to import an element of doubt even into the most trifling assertions which they might make in the course of their daily life. They did not say, "it is so," but "it seems so," or "it appears so to me." Every observation would be prefixed with a "perhaps," or "it may be."

“This absence of certainty applies as much to practical as to theoretical matters. Nothing is in itself true or false. It only appears so. In the same way, nothing is in itself good or evil. It is only opinion, custom, law, which makes it so. When the sage realizes this, he will cease to prefer one course of action to another, and the result will be apathy (ataraxia). All action is the result of preference, and preference is the belief that one thing is better than another. If I go to the north, it is because, for one reason or another, I believe that it is better than going to the south. Suppress this belief, learn that the one is not in reality better than the other, but only appears so, and one would go in no direction at all. Complete suppression of opinion would mean complete suppression of action, and it was at this that Pyrrho aimed. To have no opinions was the skeptical maxim, because in practice it meant apathy, total quietism. All action is founded on belief, and all belief is delusion, hence the absence of all activity is the ideal of the sage. In this apathy he will renounce all desires, for desire is the opinion that one thing is better than another. He will live in complete repose, in undisturbed tranquillity of soul, free from all delusions. Unhappiness is the result of not attaining what one desires, or of losing it when attained. The wise person, being free from desires, is free from unhappiness. He knows that, though people struggle and fight for what they desire, vainly supposing some things better than others, such activity is but a futile struggle about nothing, for all things are equally indifferent, and nothing matters. Between health and sickness, life and death, difference there is none. Yet insofar as we are compelled to act, we will follow probability, opinion, custom, and law, but without any belief in the essential validity or truth of these criteria.

Life of Pyrrho

In his book “The Lives and Opinions of Eminent Philosophers,” the biographer Diogenes Laërtius (A.D. 180-240) wrote: “ Pyrrho was a citizen of Elis, and the son of Pleistarchus, as Diocles informs us, and, as Apollodorus in his Chronicles asserts, he was originally a painter. And he was a pupil of Bryson, the son of Stilpon, as are told by Alexander in his Chronicles. After that he attached himself to Anaxarchus, and attended him everywhere; so that he even went as far as the Gymnosophists, in India, and the Magi. [Source: Diogenes Laërtius: “The Lives and Opinions of Eminent Philosophers Book VII: The Stoics”, A.D. early 3rd century, translated by C.D. Yonge (London: George Bell & Sons, 1895)]

“Owing to which circumstance, he seems to have taken a noble line in philosophy, introducing the doctrine of incomprehensibility, and of the necessity of suspending one’s judgment, as we learn from Ascanius, of Abdera. For he used to say that nothing was honourable, or disgraceful, or just, or unjust. And on the same principle he asserted that there was no such thing as downright truth; but that men did everything in consequence of custom and law. For that nothing was any more this than that. And his life corresponded to his principles; for he never shunned anything, and never guarded against anything; encountering everything, even waggons for instance, and precipices, and dogs, and everything of that sort; committing nothing whatever to his senses. So that he used to be saved, as Autigonus the Carystian tells us, by his friends who accompanied him. And Aenesidemus says that he studied philosophy on the principle of suspending I his judgment on all points, without however, on any occasion acting in an imprudent manner, or doing anything without due consideration. And he lived to nearly ninety years of age.

“And Antigonus, of Carystus, in his account of Pyrrho, mentions the following circumstances respecting him; that he was originally a person of no reputation, but a poor man, and a painter; and that a picture of some camp-bearers, of very moderate execution, was preserved in the Gymnasium at Elis, which was his work ; and that he used to walk out into the fields and seek solitary places, very rarely appearing to his family at home; and that he did this in consequence of having heard some Indian reproaching Anaxarchus for never teaching any one else any good, but for devoting all his time to paying court to princes in palaces. He relates of him too, that he always maintained the same demeanour, so that if any one left him in the middle of his delivery of a discourse, he remained and continued what he was saying; although, when a young man, he was of a very excitable temperament. Often too, says Antigonus, he would go away for a time, without telling any one beforehand, and taking any chance persons whom he chose for his companions. And once, when Anaxarchus had fallen into a pond, he passed by without assisting him; and when some one blamed him for this, Anaxarchus himself praised his indifference and absence of all emotion.

“On one occasion he was detected talking to himself, and when he was asked the reason, he said that he was studying how to be good. In his investigations he was never despised by any one, because he always spoke explicitly and straight to the question that had been put to him. On which account Nausiphanes was charmed by him even when he was quite young. And he used to say that he should like to be endowed with the disposition of Pyrrho, without losing his own power of eloquence. And he said too, that Epicurus, who admired the conversation and manners of Pyrrho, was frequently asking him about him.

“He was so greatly honoured by his country, that he was appointed a priest; and on his account all the philosophers were exempted from taxation. He had a great many imitators of his impassiveness; in reference to which Timon speaks thus of him in his Python, and in his Silli
“Now, you old man, you Pyrrho, how could you
Find an escape from all the slavish doctrines;
And vain imaginations of the Sophists?
How did you free yourself from all the bonds
Of sly chicane, and artful deep persuasion?
How came you to neglect what sort of breeze
Blows round your Greece, and what‘s the origin
And end of everything?

“He also lived in a most blameless manner with his sister, who was a midwife, as Eratosthenes relates, in his treatise on Riches and Poverty; so that he himself used to carry poultry, and pigs too if he could get any, into the market-place and sell them. And he used to clean all the furniture of the house without expressing any annoyance. And it is said that he carried his indifference so far that he even washed a pig. And once, when he was very angry about something connected with his sister (and her name was Philista), and some one took him up, he said, "The display of my indifference does not depend on a woman." On another occasion; when he was driven back by a dog which was attacking him, he said to some one who blamed him for being discomposed. "That it was a difficult thing entirely to put off humanity; but that a man ought to strive with all his power to counteract.circumstances with his actions if possible, and at all events with his reason." They also tell a story that once, when some medicines of a consuming tendency, and some cutting and cautery was applied to him for some wound, that he never even contracted his brow. And Timon intimates his disposition plainly enough in the letters which he wrote to Python.”


Carneades (c. 214–129 B.C.E.) was perhaps the most prominent head of the skeptical Academy in ancient Greece. According to the Internet Encyclopedia of Philosophy: “Following the example of Arcesilaus, who turned the Academy in a skeptical direction, Carneades developed an array of arguments against the dogmatic positions upheld by other philosophers, particularly the Stoics. He went beyond Arcesilaus in several respects, however. Instead of simply arguing against the positive positions of other philosophers, Carneades also set forth arguments of his own in favor of views that sometimes had never been defended before — not in order to establish their truth, but simply to counterbalance the arguments of the dogmatists and show that none of their conclusions can be conclusively established. In doing so, Carneades made important contributions to several philosophical debates. Carneades also set forth a more detailed skeptical criterion of what to believe, to pithanon which means either the "plausible" or the "probable." [Source: Internet Encyclopedia of Philosophy (IEP) ]


“Carneades continued the skeptical academy's attack upon Stoic epistemology. Arcesilaus had argued against Zeno, the founder of Stoicism, that no sense-impressions could provide a firm foundation for knowledge, since sense-impressions are always fallible. Carneades maintained this criticism against refinements in the Stoics' theory made by Chrysippus, the head of the Stoa at his time. But Carneades went beyond criticizing the arguments of other philosophers by trying to propound equally convincing arguments for incompatible conclusions, which would have the effect of leaving his interlocutor suspending judgement as to which is true. For instance, while on a mission to Rome with the heads of two other philosophical schools, Carneades gave an eloquent defense of traditional views on justice one day, and the next day offered an equally eloquent attack on those same views. (Unamused traditionalist Romans expelled the philosophers from the city as a result.)

“In arguing for contrary positions, Carneades sometimes came up with novel positions or arguments. For instance, Carneades gave a taxonomy of different possible candidates for what the highest good could be, and in so doing, came up with possibilities not canvassed by previous philosophers. He also defended original views in the debate between the Stoics and Epicureans on human freedom, determinism, and the truth-values of statements about the future. Against both Epicurus and the Stoics, Carneades argued that no deterministic consequences follow from the principle of bivalence (the principle that for any statement P, either P is true or P is false). That is because, even if it has always been true that e.g., I will brush my teeth tomorrow, that does not imply that there are "immutable eternal causes" which will bring it about that I will do so. It can be true now simply in virtue of the fact that brushing my teeth is actually what I will freely choose to do. Similarly, Carneades said that Epicureans can defend human freedom from causal determinism without positing a random atomic swerve. A person can be the cause of his actions by a "free movement of the mind", without there being antecedent causes that necessitate that the agent will do what he does. This is reminiscent of the theories of "agent-causation" later propounded by writers like Chisholm.

“Carneades also developed a detailed skeptical criterion, to pithanon — which can mean either "the plausible" or "the probable." Sense-impressions can never be a sure guide to truth, thought Carneades, but some are still more convincing to us than others — some seem plausible, and others not. We need not stop there however — we can make further investigation of convincing impressions to see if they stand up or not, as well as seeing whether they cohere with our other sense-impressions.

“Exactly how to understand Carneades' criterion was controversial even in his own day. Carneades left no writings, other than a few letters, and Clitomachus, who was Carneades' closest associate and succeeded him as head of the Academy, said he did not know what Carneades really thought. Two questions are: (1) Are pithanon beliefs supposed to be more likely to be true (as Cicero and Philo thought), or simply more plausible to the person who accepts them? (2) Is Carneades advocating to pithanon in his own voice as a criterion that a skeptic could use, or is he simply employing it in service of his arguments against the Stoics, without being committed to it himself?


“Aenesidemus (1st cn. C.E.) was the founder of Pyrrhonian Skepticism. According to the Internet Encyclopedia of Philosophy: “He was born at Gnossus in Crete, but lived at Alexandria and flourished shortly after Cicero. Aenesidemus originally was a member of Plato's Academy. From the time of Arcesilaus through Carneades, at least, the Academy was skeptical. By the time of Aenesidemus, however, the Academy had splintered into several competing factions and considerably softened or even abandoned its skepticism, as a result of its dialectical interchange with the Stoics. One head of the Academy, Philo, turned to a form of moderate fallibilism, in which one could assent to many beliefs and gain knowledge, although not certainty, while a later head, Antiochus, propounded a dogmatic and syncretistic philosophy, claiming that at bottom Plato, the Stoics, and many other philosophers were really saying the same thing. [Source: Internet Encyclopedia of Philosophy (IEP) ]

“Aenesidemus complained that the situation had deteriorated to the point where the Academics were no more than "Stoics in conflict with Stoics," and he broke with the Academy and founded his own school, taking Pyrrho as its namesake. To strengthen the cause of skepticism, he developed the ten tropes or modes of skepticism—a set of skeptical argument forms, or modes, to show that judgment must be withheld on any issue. All are based on some form of relativity—e.g., the same object can give rise to different perceptions, depending on the bodily condition of the percipient — conjoined with the claim that there is no criterion by which to adjudicate which of the perceptions, customs, etc., are correct. Although Diogenes Laertius attributes the ten modes to Pyrrho, it is likely that they owe their existence to Aenesidemus. Extracts of the ten modes are found in Photius.

“Briefly, the ten modes are as follows: (1) The feelings and perceptions of all living beings differ. (2) People have physical and mental differences, which make things appear different to them. (3) The different senses give different impressions of things. (4) Our perceptions depend on our physical and intellectual conditions at the time of perception. (5) Things appear different in different positions, and at different distances. (6) Perception is never direct, but always through a medium. For example, we see things through the air. (7) Things appear different according to variations in their quantity, color, motion, and temperature. (8) A thing impresses us differently when it is familiar and when it is unfamiliar. (9) All supposed knowledge is predication. All predicates give us only the relation of things to other things or to ourselves; they never tell us what the thing in itself is. (10) The opinions and customs of people are different in different countries.

Image Sources: Wikimedia Commons

Text Sources: Stanford Encyclopedia of Philosophy /, Internet Encyclopedia of Philosophy; Internet Ancient History Sourcebook: Greece ; Internet Ancient History Sourcebook: Hellenistic World ; BBC Ancient Greeks ; Canadian Museum of History ; Perseus Project - Tufts University; ; MIT, Online Library of Liberty, ; Metropolitan Museum of Art, National Geographic, Smithsonian magazine, New York Times, Washington Post, Los Angeles Times, Live Science, Discover magazine, Times of London, Natural History magazine, Archaeology magazine, The New Yorker, Encyclopædia Britannica, "The Discoverers" [∞] and "The Creators" [μ]" by Daniel Boorstin. "Greek and Roman Life" by Ian Jenkins from the British Museum.Time, Newsweek, Wikipedia, Reuters, Associated Press, The Guardian, AFP and various books and other publications.

Last updated October 2018

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