Copyright © 1996, Peter Suber.

Classical Skepticism
Issues and Problems
Peter Suber, Philosophy Department, Earlham College


Nowadays skeptics are stubborn disbelievers who say to anybody about anything, "No," or "I doubt it," or "How do you know?" or "I don't believe you," or "Prove it". On and off throughout the history of philosophy their reputation has been worse. Whatever one person can believe, another can disbelieve, while others may be uncertain or uninterested. To believers, everything except belief is unbelief, including all the interesting territory from outright denial through hesitation and mixed feelings to indifference. "Skepticism" became the catch-all term for these different attitudes. Moreover, in a dogmatic culture, the term became pejorative. It applied to those "who doubted where doubt was most resented and most resisted".[Note 1] "Skepticism," however, had one relatively clear and precise meaning to its inventors, the ancient Greek skeptics, and that meaning was not at all pejorative.

Compared to non-skeptical philosophical positions, skepticism is very simple. It is easy to understand, although it is commonly confused with things it is not. Skepticism in religion, for example, is not atheism. It is not even agnosticism. No genuine skeptic ever doubts or denies or disbelieves any theory, any hypothesis, or any belief. In fact, this is the only obstacle to a clear understanding of skepticism: we think we already know what it is and we are wrong. To skeptics, this unfounded pretense to knowledge is itself an example of the greatest sin they know, which is variously called rashness, conceit, pride, dogmatism, presumption, and culpable ignorance.

To the Greeks "skepticism" meant inquiry, and a skeptic was an inquirer. The skeptics so named themselves because the essence of their position was not doubt or denial or disbelief, but continual inquiry. They did not believe in the reality of a god, for example, but neither did they deny it. Nor did they even say that nobody could ever know for certain one way or the other, as agnostics do. Skeptics said instead, "I personally do not know at the moment but I am trying to find out."

The differences between this and atheism, agnosticism, and indifference have led to confusion. All three components of the skeptics' statement are important. (1) They speak only for themselves and confess only their own ignorance. (2) They speak only for the present and do not claim that their ignorance is inescapable. They do not say that knowledge is impossible for themselves or for others. (3) And they always add that despite their own present ignorance they are inquiring for the truth of the matter. They have not given up; they are optimistic —or at least hopeful —or at least undefeated —or at least unrelenting.

Let us take them at their word, for this constitutes genuine skepticism. Someone who is insincere in any of these claims is not a genuine skeptic. Or let us instead posit a skeptic who is sincere in each of these claims, and name her Nescio ("I do not know"). Many philosophers have been called skeptics who do not resemble Nescio in this regard. I will regard them as secondary types. Nescio's type of skepticism is the primary type —the most honest, the most radical, and the most challenging.

The writings of Sextus Empiricus on close examination actually present two models of skeptic. Nescio is only one of these. The second sort prefers ignorance to knowledge; instead of seeking knowledge, she seeks grounds to justify the claim of ignorance. I will call her Nesciam ("I will not know"). While Nescio makes the three characteristic claims in a sincere attempt to describe the state of her search, Nesciam utters them more as a program to be followed or fulfilled. Nescio's sincerity in the quest for knowledge makes her failures in it a surprise and disappointment; Nesciam's determination to engineer ignorance makes the same outcome a kind of success. Nescio describes her ignorance from honesty, hopes to overcome it, and endures it with humility; Nesciam describes it with a kind of programmatic insistence, hopes to preserve it, and lives it with a kind of pride.

(From now on, when I refer without qualification to Pyrrhoneans or skeptics, I will mean those of the Nescio sort, not those like Nesciam.)

Nescio may fail to find what she is willing to call truth, or she may succeed. If she fails, she will keep looking: that is what we mean by a skeptic-inquirer. If she succeeds, she will cease claiming ignorance in this three-fold way, cease being a skeptic, and will finally make her judgment that such-and-such is definitely true.

The Skeptic's Rationale and Motives

Nescio is led to this position in part by simple honesty. If she does not know for certain whether a god exists, whether there is life on other planets, whether all events have causes, or whether the majority should legislate morality for the minority, then honesty impels her to confess her ignorance. It would be rash and dishonest to say that she knew something was the case when she really did not know. It would be equally rash, however, to say that just because she did not know the truth about something, then nobody could ever know it. Others may already know the answer, for all she knows. So she will listen carefully when they speak. But they may be speaking rashly; so she will listen critically. If the truth on that point really is unknown at that time, it may still be known in the future; it may be knowable. If she devotes herself to disciplined inquiry, she may discover the truth herself.

The last point contains an important difference. Honesty tells Nescio to confess her ignorance when she is ignorant, and to admit the possibility that the ignorance is merely her own and might be temporary and curable. But honesty does not by itself tell her to try to escape her ignorance. Besides honesty, then, Nescio is guided by the love of truth and —what is subtly different— the fear of error.

Why the skeptic loves truth and fears error is an important question. But the fact that skeptics have these motives does not amount to an objection to skepticism, unless having any motives at all is objectionable (which we will explore later). Why non-skeptics love truth and fear error is just as legitimate and important a question. Should we be content with ignorance? The question has been taken seriously by Socrates, Erasmus, Montaigne, Cabell and others who were either skeptics or influenced by skeptics. The lower animals are comparatively ignorant, and yet they seem more content with their lot than humans, and untroubled by the worries and anxieties that beset us. It is from long experience that we say a little knowledge is a dangerous thing. In any case, we should be content with what is beyond our control and unchangeable; and ignorance on many large questions is a good candidate for such a thing. If ignorance is better than knowledge in any ultimate sense —and if we knew it— then honesty might also impel us to rest in our ignorance and not to disturb it with inquiry.

But we cannot know whether ignorance is better than knowledge until we have knowledge. Any choice between them before we have good grounds for choosing would be rash and dishonest. But more important, if we did not inquire for true knowledge as though we were discontent with ignorance, then we would fall prey to cleverly argued falsehoods. Then the question would arise whether it might be better to believe falsehoods than to rest in unbelief. Should we (or do we) believe anything rather than nothing? This fundamental question has also been taken seriously: by Pascal, Erasmus, Hume, Nietzsche, Vaihinger, and Cabell. Perhaps with discipline we could withstand cleverly argued falsehoods. But to do so we would have to withstand all clever arguments, for without knowing the truth we could not distinguish cleverly argued truths from cleverly argued falsehoods. We would have to commit ourselves to avoiding any and all beliefs whatsoever. That is not radical skepticism; it is a form of nihilism and a love of ignorance. Skeptics do not love ignorance; they love truth and fear error. All this is just to say that while her honesty contributes to Nescio's motive to seek truth (not to seek truth appearing dishonest), it is helped by an independent love of truth and desire to know it.

Choosing between ignorance and knowledge, and between falsehood and truth, cannot be honest unless we have true knowledge for comparison. But knowledge seems to be the kind of thing that is difficult to forget or override of we decide, after the comparison, that ignorance or falsehood is preferable. Anticipating this (not knowing it), skeptics might admit that they will be stuck with knowledge if they ever find any. While they are still skeptics, this does not bother them, for they love truth and want to know it. Of course, it would not bother them after they ceased being skeptics either.

Skeptics do seek truth sincerely. They do not say rashly whether truth is knowable, nor if knowable whether it is preferable to ignorance or falsehood. But they do seek truth sincerely as if it were both knowable and preferable. (Like all on a quest, they hope their end is attainable and worth attaining.) Because they fail to find any truth, their sincerity has been questioned by those who think it is not so very difficult to know some truth, or at least not impossible. We will examine this criticism later. But for now this should be part of the definition of a skeptic, the chief part, that she is an honest and devoted inquirer after true knowledge. Nescio's honesty brings her to confess her own present ignorance of something, whereas a love of truth takes her the rest of the way and determines her at least to try to remedy her ignorance through inquiry.

We may imagine that skeptics sought truth for any of the many good reasons that lead non-skeptics to seek truth, for the skeptic is trying to become a non-skeptic. The ultimate reason may be ominous and imperative: In Pascal's words, "if you die without worshipping the true principle you are lost."[Note 2] Or it may be vague, on the order of "Truth is somehow of supreme importance to know," with the addition that, "we will know this importance when we see it." The importance of knowing truth has traditionally been that true knowledge, or at least true faith, is a necessary condition of happiness, contentment, virtue, justice, wisdom, blessedness, salvation, or whatever was deemed the highest end and perfect fulfillment of life.

Pyrrho and Pyrrhonism

Historically, we know it was for a reason like this, with an ironic twist, that made the inquiry for truth a decisive part of skepticism. The Greeks sometimes called skepticism, Pyrrhonism, after Pyrrho, an austere teacher of serene non-commitment. He was not a pure skeptic himself, in the epistemological sense, but his teachings led directly to what we now call skepticism.

Pyrrho was born a little over a century after Socrates. Plato was about 60, and Aristotle about 20, when Pyrrho was born, and Pyrrho lived to see both of them die. Pyrrho lived to see the rise and fall of Alexander the Great, the civil wars in his empire, and the opening of the Eastern world to the West. This meant that Pyrrho witnessed the splintering of Platonism and Aristotelianism into many bickering schools. He travelled to India with Alexander's army and witnessed the spectacle of novel Eastern customs, at once utterly different from the Greek but equally civilized and supported by a reflective philosophical tradition. He witnessed the social and political chaos, war, and strife that followed the death and succession of Alexander.

(Socrates 470-400 BCE, Plato 428-348 BCE, Aristotle 384-322 BCE, Pyrrho 360-270 BCE, Alexander 356-323 BCE.)

Some scholars find a political origin to Pyrrho's skepticism in this, on the theory that traumatic periods produce disillusionment and resignation, the souring and obsolescence of traditional beliefs, a tenacious relativism of beliefs, virtues, and habits that will not assign absolute superiority to any, and a need for new methods of coping in a hectic world.[Note 3]

There is probably some truth in this, and it does seem that skepticism recurs through history in the periods of greatest upheaval and dissolution. But it is unfair to skepticism to reduce it to the play of historical forces and forget that it has its immanent 'reasons' that have a claim on all of us, regardless of our circumstances. That is, philosophies have grounds, not just causes. Pyrrho's own biography, scanty as it is, gives a good idea of how these reasons operated in his life.

Pyrrho began his intellectual life as a student and disciple of the Stoics, who taught that peace of mind was the highest end of life and that a knowledge of truth was required to attain and maintain it. Pyrrho accordingly sought truth. But he heard the Stoics say one thing was true, the Pythagoreans say another, the atomists another; he heard many versions of Plato's truth and of Aristotle's. He heard disagreements among the disciples of Anaxagoras, Heraclitus, Parmenides, Empedocles, and Protagoras. For every question of interest to philosophy he heard the Stoic doctrine contradicted by dozens of other doctrines, all of which also differed among themselves. What was worse, each position had reasons and evidence to support itself and to subvert and refute its opponents. To Pyrrho it was a standoff. He gave up in despair and admitted to himself that he could not decide among them and did not know what was true.

Voila! He discovered that his confession of ignorance had given him peace of mind. He had ironically attained the goal of all Stoicism by giving up and reversing its means. He had found a tranquillity in honestly confessing his ignorance. Moreover, his tranquillity seemed as durable and serene as the Stoical peace of mind that presumed to depend on true knowledge —and that embroiled the Stoics in endless disputes and other perturbations.

Sextus Empiricus compares this irony to the case of the Greek painter, Apelles, who while painting a horse had trouble getting the foam on its mouth to look right (I.28).[Note 4] He tried all the subtleties of technique he knew but could not get the effect he wanted. Giving up in despair, he threw his sponge at the painting, and it left the perfect impression of foam.

That Pyrrho achieved his peace of mind accidentally and unexpectedly may itself be no accident. As we will see, to avoid inconsistency or rashness a skeptic may be required to claim that the connection between the confession of ignorance and peace of mind is ad hoc, adventitious, unlooked for, and a perpetual surprise. To put it more sympathetically, Nescio will never positively expect peace of mind to follow from the confession of ignorance (I.29), even if she always finds it to do so. Nesciam, however, does expect peace of mind from the attainment of ignorance, and pursues skepticism in order to achieve it (I.12, I.190, I.205, I.232). But not even Nesciam will rashly confess ignorance when knowledge may be available simply to cheat herself with a false confession and hope to find peace.

Pyrrho may have achieved piece of mind unexpectedly as a consequence of confessing his ignorance. But others saw this is as a quasi-spiritual regimen that could be imitated. Nesciam seems motivated to retrace Pyrrho's steps, which means to do so without the element of surprise or unknowing. Nescio may seek knowledge and find ignorance and peace of mind by the irony of failure; but Nesciam seeks peace of mind through attainment of ignorance; this makes the avoidance of dogmatism a program, not a failure on the path to knowledge.

Pyrrho realized that the ignorance he confessed to himself was very different in kind from the ignorance of children, dogs, and stones. It was learned ignorance. It was the result of intellect and inquiry, of mind trying to know and failing, of reason propounding questions to itself that it could not answer. It was a painfully acquired recognition of his limitations and himself, not the barren ignorance that never tried to conquer itself. Ever since Socrates learned that all his wisdom consisted in knowing his ignorance,[Note 5] skeptics have prized learned ignorance as the first step in honest inquiries toward truth.

Learned ignorance is not an end in itself. However, in the skeptic's experience inquiry usually fails and when it fails honest inquirers recognize learned ignorance to be the result. But before any serious inquiry can begin we must admit that we do not know. Learned ignorance is humility and honesty, the opposite of rash prejudice, and at least the ground (if not the consequence) of any genuine investigation.

Pyrrho, or his students, realized that the peace of mind he attained was made possible only by the search for truth (I.205). This might have been why they continued to search for truth themselves. For it was open to them to quit the search for truth once they attained their ataraxia or peace of mind. But no skeptic did this. Another reason may have been that their tranquillity in learned ignorance might appear, or actually be, dishonest if it were not continually challenged and nourished by the search for truth. It is also possible that Pyrrho and other skeptics hoped, or conceded as a possibility, that a better peace of mind could be attained through true knowledge than through learned ignorance. In any case classical skepticism had two goals: truth and peace of mind. We might say that true knowledge was the theoretical end of skepticism, and peace of mind the practical end, although the skeptics themselves never made this distinction.

Sextus occasionally writes as if the practical end were primary for many Pyrrhoneans, as it was for Pyrrho himself (I.12, I.25, I.215). Even within the theoretical or epistemological pursuit, similarly, some Pyrrhoneans preferred failure (continued skepticism) to success (dogmatism) in their inquiries, at least when peace of mind followed the confession of ignorance (I.30, I.100, I.204). Others admitted their willingness to assent to a good argument when they saw one (II.251). Nescio is of the latter type, and prefers truth to peace of mind. Nesciam is of the former type, and prefers ataraxia to truth, and believes that ignorance or non-assertion leads to ataraxia.

In a passage that is ironic but not insincere, Sextus says there is a third end of skepticism: to cure dogmatists of their rashness and self-conceit (III.280-281). Skeptics seek this end because the skeptic is "a lover of his kind" (III.280).[Note 6]

Modern skeptics drop the goal of peace of mind and pursue truth unremittingly. They become skeptics through a sense of epistemic duty and follow inquiry wherever it may lead emotionally. They typically achieve despair, not tranquillity. Some of the reasons for this result will be explored.

Details of the Way of Skepticism

Some of the skeptics' own technical terms are necessary to a deeper understanding of their position and its problems. Our great and only systematic source of these terms and fine points is the four-volume summary of Pyrrhonism by Sextus Empiricus, a Greek physician born over five centuries after Pyrrho. Many of the ancient Greek skeptics wrote nothing at all, like Socrates, Pyrrho, Arcesilas, and Carneades, or else their writings have not survived, like those of Timon of Phlius and Clitomachus. Sextus had access to many of the writings that are lost to us and, more importantly, to the oral teachings of the skeptics' heirs and disciples, whose arguments had become extremely refined by his time.

(Pyrrho of Elis 360-270 BCE, Timon of Phlius 315-225 BCE, Arcesilas of Pitane 315-241 BCE, Carneades of Cyrene 213-129 BCE, Clitomachus, 157-110 BCE, Aenesidemus 100-140 CE, Sextus Empiricus c. 160-210 CE.)

Sextus starts (I.1) by saying that the natural result of any search for any truth is that the inquirer either claims to have discovered it, claims it cannot be discovered by anybody, or claims personally to have failed so far to discover it and persists in the search.[Note 7] The one who claims to have found a truth is called a dogmatist; the one who denies it is discoverable is called an Academic skeptic; and the genuine or Pyrrhonean skeptic is the one who keeps on searching.

Academic Skepticism

The second position asserts that at least some truths are completely unknowable (at least by humans). This group represents a type of skeptic, the Academic skeptic, so named because they belonged to the Platonic Academy which gradually adopted this position after Plato's death. Genuine or Pyrrhonean skeptics are not Academic skeptics. Pyrrhonean skeptics do not deny that knowledge is possible; in fact, they hope it is. The Academics do deny, sometimes dogmatically, that knowledge is possible, and so they may be vulnerable to the retort, "Do you know that knowledge is impossible? Either you cannot know that, or some knowledge is possible."

This retort and its variations are the single most common objection to skepticism in the philosophical history of dogmatism. Yet it applies to very few Academic skeptics, and to no Pyrrhoneans at all. Still, most educated dogmatists —non-skeptics— believe that skepticism is self-refuting, that its form belies its content, that it dogmatically witnesses itself or, in Descartes' version of the objection, that doubting cannot doubt itself.

Academic skeptics were aware of the retort and were not so brazen and foolish to court it undefended. Some followed Cicero and held that no knowledge is possible except this one truth that no other knowledge is possible. The exception may be hard to justify, but to claim it at least seems to be free of contradiction. Others held that quite a bit of knowledge is possible, but unfortunately the unknowable is also a large realm and includes all the really important questions, such as the nature of human beings and the soul, the gods, change, reality, freedom, immortality, why we are here, and what we ought to do.

According to Cicero, at least four ancient philosophers took the position that nothing could be known except the proposition that nothing (else) could be known: Socrates, Varro, Antipater, and Cicero himself.[Note 8] Others, either in mischief, transcendental consistency, or naiveté, took the position that nothing could be known including the proposition that nothing could be known: Arcesilas, Carneades, and Chian Metrodorus.[Note 9]

The latter position is much like that which Seneca attributes to Protagoras:[Note 10]

Protagoras declares that one can take either side on any question and debate it with equal success —even on this very question, whether every subject can be debated from either point of view.

That is, all positions are equipollent with their contraries, including this position. This is not obviously a self-contradictory position; it may preserve its consistency through 'self-cancellation' in the way that many Pyrrhonean arguments do (discussed further below).

Most Academics took one of these two positions along with a third: they limited themselves to denying the possibility, not of knowledge per se, but of certainty. We might perchance hit upon the true explanation of something important, but we would never know it because it would be uncertain and in no way discernible from the competing false explanations. Some of our sensations and perceptions may be veracious, but they contain no inner mark distinguishing them from the mendacious and illusory.[Note 11] And no external mark is trustworthy.

The sense in which both Pyrrhonean and Academic skeptics convert the search for truth into the search for certainty, and what price is paid for this conversion, will be discussed later.

Genuine or Pyrrhonean skeptics do not deny outright the possibility of knowledge or of certainty, whether on big questions or small. But neither do they affirm these things outright. Very precisely, a Pyrrhonean claims not to know personally, at the moment, whether or not knowledge or certainty is possible. So she is vulnerable to no retort at all, unless it is, "Do you know that you don't know, personally and at the moment, whether or not...?" Her response to this is complicated and will be reviewed in a minute. The Pyrrhonean seeks knowledge and certainty as if they were possible, which may be the only honest policy.

A second major difference between Pyrrhoneans and Academics is that the latter accept a view that has been called "probabilism". Academics allow themselves to say that some propositions, while not "known", are "more probable" than their contraries. Pyrrhoneans do not accept probabilism (I.222, I.226ff, I.231).

(Sextus contrasts Pyrrhonean and Academic skepticism at I.3, I.193, I.200, I.220-235, esp. I.226. If we say that Nesciam is closer to academic skepticism than to Pyrrhonean, it is only because we have decided that Nescio will be our model of the Pyrrhonean. Sextus offers the dual Nescio-Nesciam character as the Pyrrhonean and contrasts this character with the academic skeptic.)


The next important term is dogmatism, the proper opposite of skepticism. Our English word comes directly from the Greek, dogma, an opinion, belief, notion, decision, judgment, or public decree. It is related to our words "doctrine", "doctor", "orthodoxy", "paradox", and "disciple".

The dogmatist is certain that knowledge is possible, because he is certain that he has some. A person is still a dogmatist even if he is not certain, but still asserts something to be true, whether on a hunch, an intuition, a perceived plenitude of evidence, mystical impulses, blatant prejudice, or idiotic repetition. An inquirer need not believe that knowledge requires certainty, or that truth-assertion requires knowledge, to be a dogmatist. He need not believe that everything is knowable, as Hegel does, to be a dogmatist. He may believe that comparatively little is knowable, as Hume and Kant do, and still be dogmatic. The dogmatist need not even be an inquirer; he may have picked up his beliefs from any source without any inquiry at all. A person is a dogmatist, then, if he has any beliefs whatsoever. Sextus too uses this minimal sense: a dogmatist is one who is willing to assert at least one proposition to be true (I.223).

Sextus sometimes uses a slightly broader sense: a dogmatist is one who asserts a proposition to be true by virtue of some analogy or demonstration (I.147), who asserts it deliberately (I.230, cf. I.197), and whose assertion concerns a "non-evident" proposition (I.197, I.208, I.233). Some of these qualifications will be discussed later.

So of course we are all dogmatists. It is better, then, not to attach too many derogatory meanings to the word. The skeptics used the word in a neutral, descriptive sense. But most philosophers —most dogmatists in the skeptics' sense— use the word in a normative and pejorative sense to denote thinkers who announce their alleged truths without giving reasons or evidence for them, or without taking the opposing reasons and evidence into account, or generally for arrogance and presumption and unearned certitude. This sense of "dogmatism" is obviously related to the skeptics' sense. But I will use the term here without any of the derogatory connotations.

To clear the word even further, we should be aware that virtually all the great agitators and changers and martyrs in history have been dogmatic in an extreme way. This is true even if much of their effect came from a revolutionary set of questions or doubts. Socrates is a conspicuous, but rare, case of a world historical actor whose effect was almost entirely due to a skeptical temperament.

But at the same time we should be aware that skeptics are just as effective in their equally important work at the destruction of dangerously false ideas. As for the sense in which skeptics are ineffectual, they would say they have good reasons for it. Dostoevsky's underground man said a large amount of stupidity is required for the belief that our actions have an infallible basis in thought[Note 12]. Stupidity or intellectual dishonesty, the skeptic's charge against the dogmatic person of action may be balanced by the dogmatist's counter-charge, for example in the words of Edmund Burke, that all that is required for evil to triumph is for good people to do nothing. This debate will never cease raging. But before one judges skepticism harshly for comparative inactivity, one should realize that skeptics can act (as we will see), remember that critical questioning is a force in history as powerful as military action, and scan the long history of good and evil actions that dogmatists have brought into the world.


The dogmatist asserts that something is true. He makes judgments he is willing to stand by. The skeptic suspends her judgment; she waits until she is sure, which may be never. Suspension of judgment (in Greek, epoche), not doubt and not denial, is the skeptic's characteristic activity. This is the next important technical term. The Greek word epoche means to check, cease, suspend, stop, or pause in some activity that otherwise or normally occurs. The skeptics applied the word to judgment, while in other contexts Greek speakers applied it to sunlight (in eclipses), menstruation (in pregnancy), payments on a debt (in default), musical vibrations of a string (at the nodes), and the passage of time (at turning points or "epochs"). The English phrase "suspension of judgment" captures the gist of the skeptical usage well, but loses the flavor of a versatile common word doing philosophical work. If we had to coin a word to capture more of its sense, "ajudice" (meaning non-judgment, on the model of "prejudice", meaning pre-judgment) might work well.

(Sextus uses two other terms closely related to epoche. The first is arrepsia (I.190), referring the equipoise of a balanced scale, inclining in neither direction. The second is aoristia (I.198), to be undecided, indeterminate, uncertain, without definite ideas.)

With its implication of checking or pausing an otherwise ongoing activity, epoche suggests an expectation that judging will resume again. Hence it appears that the Greeks who used this word instead of another (such as aporia or adelos) hoped that truth was attainable. This supports our reading that the genuine Pyrrhonean is more like Nescio than Nesciam in placing truth above ataraxia as an end of skepticism.

The skeptic refrains from judgment; she does not judge one way or the other. She takes no position and keeps inquiring. Doubt differs from suspension of judgment in suggesting an inclination toward negation. Epoche inclines in no particular direction. Epoche is the skeptic's characteristic mental attitude. Sextus will not positively say that it is better than assent, although he will say that it appears to be better (I.233, III.238).

Doubt seems to require grounds, or reasons, to justify the negative tilt of judgment. Doubt might well be a judgment that something is doubtful or dubitable. Whether epoche is 'groundless' is a complicated question, as the following dogmatic objection illustrates.

Some dogmatists object that skeptics must have reasons or grounds for suspending their judgment on a given question, or else their hesitation is stubborn and arbitrary —dishonest. But, the objection continues, skeptics cannot acknowledge any reasons if their judgment is truly suspended. This dilemma is spurious to the genuine skeptic. Looking at a question, and at several conflicting answers, an Academic skeptic would say (for some reason) that the question could not be decided, not just by him and not just in the present, but could not be decided by anybody ever. We would ask what his reason was for such a remarkable statement. If he gave us one, even if we were tempted to agree with it, we might accuse him of believing it. That might be inconsistent with his extreme position on knowledge and certainty.

The Pyrrhonean skeptic is not caught in this bind. Her suspended judgment is neither stubborn and arbitrary, nor based on a reason with which she might be confronted and charged with dogmatism and inconsistency. She suspends her judgment, first of all, only after examining all the proposed answers she can find. Remember, she is seeking truth and wants to find it. She examines all the arguments and evidence given to support the answers, in order to be able to decide between them intelligently. If she finds one answer better supported than the others, even after examining the merits of the alternatives and the objections of opponents, then she will give her assent and become a dogmatist. Any other policy would be intellectually dishonest.

But if she finds that all the arguments and evidence balance and cancel each other, so that she cannot pick just one without being arbitrary and dishonest, then and only then will she suspend judgment. She will say, "I do not know which, if any, of these answers is true. I am still ignorant and must continue my inquiry."

The skeptic suspends her judgment for default of a good reason for exercising it. Because no reasons stand unchallenged for swaying her judgment, she refuses to judge. The procedure is not at all stubborn or arbitrary, and it is very rational. If we grant that the skeptic would judge if she had a reason or ground for judgment, i.e., that she sincerely seeks truth and is willing and even eager (sometimes desperate) to become a dogmatist, then is it, again, the only honest policy to suspend judgment in the face of a balance of reasons.


Skeptics call this balance isosthenia, a Greek word meaning equal strength. It is often translated by the word "equipollence" which uses Latin roots to express the same meaning. I will use both "equipollence" and "isosthenia".

Isosthenia is not so well defined by Sextus Empiricus, perhaps because it is an inherently informal and inexact notion. It is unclear whether only dogmatic statements can stand in isosthenia (I.193) or whether sense impressions, thoughts, theories, and arguments can stand in isosthenia (I.8f, I.197, I.201, III.49, III.65, III.82; cf. III.135). We may say that isosthenia is the apparent balance of certainty, probability, plausibility, credibility, and rationality of two or more conflicting ideas —or the apparent balance of their uncertainty, improbability, implausibility, incredibility, and irrationality. Isosthenia is the apparent equality of all the conditions that we put on ideas for acceptability. When isosthenia appears, it is a sufficient ground for skeptics to hold off and refrain from judgment, to wait and seek for more evidence that might tip the balance.

Note that isosthenia does not refer to an actual or objective balance of strength, but only to a balance that appears equal to us at the time (I.196). For the same reason that isosthenia cannot be objective, it cannot be exact either. Plausible (pithanai) arguments on both sides are enough to create it, Sextus says (II.79, II.192, III.29). A perfect or exact balance might not ever appear or even be recognizable. But it is sufficient for the purposes of honesty to declare ideas to be equipollent whenever we are incapable of making a single and exclusive choice among the possibilities without rashness, prejudice, or some degree of arbitrary preference. Hence, in practice isosthenia for us (or for me at the moment) is necessarily more precise and useful than isosthenia per se.

Now it is very important to note that we could never say whether or not a mass of theories stood in isosthenia unless we examined them all impartially and looked for ourselves. Isosthenia must be sought. It will not jump out at us. It would be rash and dishonest to presume that a particular theory is just as acceptable as all of its alternatives. To be honest in inquiry one must be willing and eager to see an imbalance, to see that some one possibility is better supported than the alternatives. This need hardly be said to dogmatic inquirers, whom the skeptics would call over-eager in this regard. But it is necessary advice to the skeptical inquirer who may too easily become stubbornly negligent of the fine differences among types of reasons, evidence, and support. It is just as prejudiced to presuppose before inquiry that isosthenia obtains as it is to presuppose before inquiry that a certain single theory alone is true.

So Nescio does inquire and she suspends judgment if and only if she discovers the isosthenia of the alternatives which prevents any honest judgment. She enters inquiry willing and wanting to judge; if she does not judge after all, it is only because she was prevented. She carries no bias toward the negative or the positive. She is neither dubious nor credulous. She is intellectually honest and confessedly ignorant. If the reasons and evidence available to her at the moment do not push her toward affirmation or denial, then she will not affirm or deny anything, but will suspend her judgment and continue her inquiry.

Up to this point skepticism looks like the most harmless and good-natured of all approaches to a philosophical problem. Nobody could complain about the precept that we should confess our ignorance when we are ignorant, and not pretend to a knowledge or a certainty that we lack. To love truth and fear error, and to act accordingly, are very wholesome. Few could disagree that we should suspend our judgment when we lack a sufficient ground for judgment. In fact, embodied in intellectual honesty, these practices are not only unobjectionable but positively praiseworthy.[Note 13]

Introducing the Bass Clef Theme

What has worried some very honest dogmatists, however, is the usual result of this humble beginning. To adopt these practices of the skeptic may seem the very duty of all philosophers and scientists and inquirers of all kinds, and many have said so. But many dogmatists would like to write over this path the warning that Dante found inscribed over the gateway to Hell, "Abandon Hope All Ye Who Enter Here".

For it happens that the Pyrrhonean skeptics end up believing nothing at all except that appearances appear (I.19) —which may not even be a belief. Sometimes they even appear to suspend judgment on whether appearances appear (II.50, II.70), but in any case say that only mental states are apprehended (I.215, II.72). They do not quarrel with appearances themselves, but only with the accounts given of appearances (I.15, I.19, I.22, I.59, I.78, I.87, I.93, etc.). And it just happens that they suspend judgment on (because they have found equipollence for) each and every account —interpretation and explanation— of appearances.

We should probably take the word of the ancients that this led them to a profound peace of mind. It has not done so for moderns. Something has changed in our intellectual and cultural circumstances, and this radical learned ignorance has led modern thinkers, at least since Pascal in the 17th century, to despair. Of all the changes in the spirit of the times one of the most indicative is that the uncertainty of things, which skeptics make their business, is no longer a matter for mere observation, but for lamentation. It no longer soothes us to abandon ourselves to it. Instead of serenity it produces anxiety; it is not quietude but loss, not purgation but incompleteness.

I said 'it just happens' that these beginnings lead to a virtually universal suspension of judgment. For just as Nescio will not expect peace of mind to follow her suspended judgment (ataraxia to follow epoche), neither will she positively expect investigation to discover isosthenia among all the possible answers to all the possible questions. It just happens that way. To say in advance that no statements will be found more certain than their contraries would be rash and dishonest. But it is the skeptic's experience, looking back, that it is so.

(For Nescio it just happens that careful examination leads to epoche; for Nesciam it is nudged by will and contrivance.)

Why does Nescio's inquiry characteristically lead to isosthenia and a suspended judgment? That is what dogmatists want to know, for their inquiries lead to discoveries and judgments and assertions and preferences. The answer lies in the skeptic's simultaneous love of truth and fear of error —and in her honesty. As we saw, Nescio sincerely wants true and certain knowledge, so she pays sympathetic attention to those who claim to have it. This is her love of truth at work. But her fear of error makes her listen critically. It is something like an intellectual duty to test ideas severely: not to shoot them down or refute them, but to set them against their contraries and compare the relative strengths of their supporting arguments and evidence. She wants truth, and if somebody tries to teach her a counterfeit, she will owe it to herself to see through it, check any impulse to affirm it, consider the merits of the alternatives, find its isosthenia with the alternatives, suspend judgment, and keep looking.

Without examining all the alternatives, the truth might not appear in the competition. Without a test of fire, error might survive the competition and prevail.

The Tropes

This too is a harmless and praiseworthy practice. But to help them in their critical task, the skeptics evolved an arsenal of arguments that subvert virtually all the statements that philosophers and scientists would ever wish to make about anything. These arguments are called the "modes" or "tropes". The four-volume chronicle of ancient skepticism by Sextus Empiricus is almost entirely devoted to these arguments. To many it is an encyclopedia of negation. If you want good grounds to deny a belief that you cannot refute by yourself, look it up in Sextus Empiricus. Dogmatists in all ages have used it selectively and found it helpful in the destruction of opponents. The trouble is the completeness of the tropes and their plausibility. They virtually demand our assent, and yet together they wipe out all our beliefs.

What are these skeptical tropes of universal devastation? Different skeptics organized the tropes into different groups of varying size and content, but in each case the complete set was a thorough-going assault on the claims to knowledge and certainty. Some sets are large and cite many examples of different animals with different senses, different cultures with different customs, and different states of health with different moods and perceptions. Some stress the relativity of perspectives so that all perceptions, judgments, and valuations are cancelled by others made from different standpoints. Many go into agonizing detail about particular fundamental topics, such as mind and matter, change and causation, freedom, virtue, and god.

But the most interesting are those that restrict themselves to the logic of support and justification, and without apparently making any positive or dogmatic assertions about anything, confront all dogmatists with paradox and embroil all who reason in as much uncertainty as those who do not.

For example, there is the paradox of the criterion, the standard by which we hope to recognize truth when we find it, or by which to reject some possibilities as certainly false. Some dogmatists say there is a criterion of truth and some say there is not. This is the first problem. To decide between them, apparently, we first need a criterion. So we cannot decide the question without presupposing a particular decision, or begging the question. Circular reasoning is not knowably invalid, but anything supported by it is supported exactly as well as its contrary can be supported, which creates isosthenia, which demands that we suspend judgment.

But if we allow criteria for the sake of argument, then we must ask which criterion is the true criterion. (By the way, Sextus loves to grant dogmas like this 'for the sake of argument' in order to demolish them with wave after wave of objections; he also claims not to know whether any single objection suffices.) We can only validate or certify a criterion as the right criterion, or even as a likely, decent, or useful criterion, by using a criterion of what makes a good criterion.

But here we encounter a classical and recurring skeptical dilemma. Either our one criterion certifies itself, which is circular, or a second criterion certifies the first, in which case we will need a third to certify the second, and so on ad infinitum. So it seems we must either beg the question or fall into an infinite regress.

Nothing is left except to forgo all support and simply claim (stipulate or hypothesize) that the criterion is a good one. But others will do the same for different criteria, on equal authority, and the resulting disagreement will be final, clearly equipollent, and ripe for suspended judgment. If the criterion is affirmed hypothetically, just to see where it goes and how it works, then all the statements it validates as a criterion will be equally hypothetical.

Or the criterion may be tested by its fruits. If it validates certain statements and not others, then we will say it is a good criterion. But this is just another way to beg the question, for it presupposes what is to be proven, namely, that we know which statements are true, or that the criterion is good and validates only true statements. Or again, this is to use the resulting statements as the criteria, and the problem reappears.

So it seems that a criterion is not supported at all, or is supported by circular reasoning or by an infinite regress. In any case its support is inadequate for genuine certainty about the criterion. In particular, other criteria could always be proposed with equipollent support. Then suspension of judgment on which, if any, is the true criterion would be required by honesty.

But if no criterion is ever certain, then no statement is ever certain, for statements are made certain by supporting arguments or evidence, which are discerned by virtue of a criterion. Of course even this claim is uncertain.

Then there is the paradox of proof. An alleged proof may be valid according to some given rules of valid reasoning —and skeptics have attacks on all rules of validity, in general and in particular— but its conclusion is only demonstrably true if its premises are true. But we only know that the premises are true if they themselves are proven. Clearly we are again entangled in the dilemma of circular reasoning and infinite regress. If we prove the premises, then their proof will have its own premises that need proof, and we are committed to an infinite regress of proofs that we can never supply. The result is that nothing is ever proved with finality. If unproved premises can make good proofs, then we can invent unproved premises from which we could derive any proposition whatsoever, thereby putting all possible conclusions into isosthenia.

If the conclusion simply restates the premises tautologously, which modern logicians say is the only valid type of proof, then to accept the conclusion as true simply because it is validly concluded is to accept circular reasoning that could as well prove the opposite conclusion.

Of course, none of this proves that proofs are impossible, for then a proof will have been given to display their possibility. Or, if such a proof has been given, then it "cancels itself" (explored below). This leads to an observation that is often missed. The skeptics did not believe that the tropes proved that some conclusions were false or that some kinds of reasoning were invalid. In dogmatic hands the tropes might provide such refutations, paradoxical as some of them would be. But the skeptics used the tropes to provide only enough subversion to establish equipollence and suspend judgment, not to affirm or deny anything outright (II.79, II.103, II.244, III.81, III.135, III.139).

A somewhat dizzying example of a logical trope clearly aimed at certainty in this way, rather than truth, might be called the 'No One Can Judge' trope. If a dogmatist tries to answer the skeptical challenge by putting forth some claim that is supposed to be known with certainty, then he will fail. For Nescio can reply that the dogmatist's claim is a candidate for certainty, and as such subject to judgment, and therefore ineligible to decide the dispute about certainty (I.48, I.59, I.90, I.112-113, II.36-37, III.182). To let it play both roles is to let a party be judge in his own case, or to beg the question in a way that any other position could do equipollently.

Let us see how some of these tropes deal with a typical dogmatic assertion. If somebody says that there is a god, then Nescio in her love of truth will pay attention. In her fear of error she will ask why she should believe it. How do you know a god exists? What are your reasons? How do you overcome the objections? Many answers are possible to these questions. "The Bible says so." So the Bible is your criterion, Nescio says. "The harmony of existing things requires a supreme intelligence." So the harmony of things is your criterion. "The alternative to the hypothesis of god is a self-contradiction." So the principle of non-contradiction is your criterion.

Nescio will probably begin her criticism with particular questions, such as why should the Bible be believed and exactly what does it say, why is your interpretation of the text to be trusted; why do you believe in the harmony of existing things and why would their harmony require a supreme intelligence. But she does not have to do this. She will get the dogmatist's criterion sooner or later. When she does she will ask why the criterion should be trusted. Dogmatists (should) have learned to their eternal frustration that all the answers to this question play into the skeptic's hands. "The criterion should be trusted because... Because such-and-such (a proposition), which is supposed to be true, true by a criterion, a criterion we should trust because..."

Although this line of attack suffices for any dogma, it is far from the skeptic's only song. With similar arguments she can show that no method should be trusted, that no point of departure is certifiably adequate (I.166), that empirical verification never ends (I.177) and logical confirmation never begins (I.166). The skeptics analyze the ways in which dogmatists dogmatized or excused themselves for asserting something to be true; they did not find all these ways to be bad, just inadequate to ground any idea better than its contrary (I.169).

Does the skeptic believe, dogmatically, that a criterion (for example) should not be trusted if its sole support is an infinite regress? This is a question dogmatists have long asked. Does the skeptic believe that circular reasoning is fallacious in the sense that it should not be trusted? Does the skeptic have a dogmatic belief in the tropes?

The answer is no. Infuriatingly to many, skeptics do not affirm or deny the soundness of the arguments they use to dissect dogmas (I.35). As the examples show, skeptics need not believe that proofs by circular reasoning or infinite regress are invalid; they need only observe that such methods allow equipollent support for contrary conclusions. A criterion supported solely by self-validation or by the stipulation of proponents is not to be trusted. But the reason is not that self-justification and the ipse dixit of the faithful are knowably untrustworthy; it is that the criterion's support would then be equipollent to that for conflicting criteria. It might be the true criterion (for the tropes do not falsify), but isosthenia obtains with its contraries (II.79, II.103, II.130). The intellectually honest must suspend judgment.

Skeptics neither affirm nor deny that they have understood the dogmatist's position (II.1ff), that the tropes have eroded the claim of his dogmas to truth, or even that the tropes themselves are to be trusted (I.35). In an important sense the skeptic never speaks for herself, which might require some dogmatic commitments on her part. She enters the world of the dogmatist and explodes it from within. This is sometimes called arguing (or speaking) ex concessis or by concession. When one argues ex concessis one hypothetically or provisionally adopts the premises of the opponent. The skeptic provisionally adopts the principles and criteria and standpoint of the dogmatist. If she finds a contradiction, she points it out, not because she believes contradictions falsify ideas, but because the dogmatist believes they do. If she reduces the criterion or the method to a begged question or an infinite regress, it is not because she believes these will undermine the theory, but because by the dogmatist's standards they will. When she is not arguing ex concessis the skeptic juxtaposes conflicting theories and finds isosthenia.

The skeptic speaks for herself only when she is finished applying the tropes and surveys the ruins. Then she says the dogma may be true, but it is not more certain or more likely to be true than the alternatives. She has established equipollence by making the theories on a particular question equally uncertain and unfounded. Then she says, "At the moment I do not personally know which, if any, are true, so my inquiry is not over yet."

Now we can see why some people have thought the skeptic insincere in her claim to keep looking. What does she expect to find? It may be obvious to us that by using the tropes mercilessly the skeptic will be able to demolish the certainty of any theory whatsoever. But it is not obvious to her. Only an Academic skeptic will look at the tropes and at the history of our attempt to understand the nature of things and will say in advance that all dogmas will be vulnerable, that nothing is certain except this, that nothing is certain. Part of the Pyrrhonean's public relations problem is that we dogmatists tend to believe that in her heart of hearts she is an Academic skeptic who positively denies that we will ever acquire any certainty beyond this one, that nothing is certain.

But the honest Pyrrhonean is not an Academic skeptic. She will not assert that all dogmas can be made equipollent and uncertain by the tropes. Not having examined all dogmas, her honesty restricts her to discussing only those she has examined (I.198-99, I.200, I.202-03, I.208), and she keeps on looking. So she is more optimistic than we who jump to conclusions on her behalf. But she is also very pessimistic about the likelihood of any dogma ever proving itself with absolute certainty. In an honest Pyrrhonean who has not become an Academic skeptic, this pessimism will not be mitigated by occasional discoveries, but neither will it mean the end of inquiry. As Pascal said, "I can only approve of those who seek with groans."[Note 14] The result of this pessimism will be explored a little later.

These considerations show that there can be honest Academic skeptics too. While a Pyrrhonean becomes pessimistic in a long life of inquiry, she always keeps the door open that certainty might be attained tomorrow by novel means. An Academic skeptic is rarely an unsophisticated doubter who should think twice and become a Pyrrhonean; Academics are those who admit that their pessimism about finding certainty has extinguished their hope.

Those who think the Pyrrhonean is really and secretly an Academic skeptic are unwilling to admit that intellectual honesty, humility, and a reluctance to generalize rashly can so completely prevail over all the other inclinations of the human being. They may be right, but a skeptic could easily suspend judgment on this psychological dogma, and the honest search for knowable truth may require us to do so.

Historical interlude

The arsenal of Sextus Empiricus was introduced to Europe just as Martin Luther's attack on the Catholic Church was building steam and shaking some old certitudes. The works were unknown throughout most the Middle Ages because they were sparsely distributed and untranslated from Greek. In 1562 a partial Latin translation was published in Paris, and by 1569 the complete works of Sextus Empiricus were available in Latin.

These publications spread the word quickly, and were used about equally by Reformers and Counter-Reformers. They were responsible for much of the intellectual anarchy and skeptical crisis that followed upon Luther's writings and for which Luther has been blamed. Luther did set the stage for the very wide reception of Sextus' writings, but they in turn made Luther's reforms seem miniscule by radical standards, and for that reason more acceptable to the new moderate skeptics and less acceptable to those who saw Sextus as the devil and Luther as his herald. From the standpoint of the "new Pyrrhonists" (as they were called) even Luther was too dogmatic, while from the standpoint of anybody with a faith to preserve, he seemed to set loose the hounds of all doubt and universal disbelief.

Sextus in effect hardened the battle-lines that Luther had drawn and extended the problem from papal authority and a few other questions to anybody's authority (or infallibility) and the warrant for any beliefs at all. Pierre Bayle, the 17th century's greatest skeptic, said that the modern era in philosophy did not begin with Descartes or Montaigne, but with the re-introduction of the works of Sextus Empiricus.[Note 15]

(Martin Luther 1483-1546; Luther posted the 95 Theses on the door of the Palast Church in Wittenberg, October 31, 1517; Luther excommunicated and declared heretic by Pope Leo X, 1520; Michel de Montaigne 1533-1592; complete Latin translation of Sextus Empiricus, 1569; first English translation of Sextus, 1591; Rene Descartes 1596-1650; first Greek reprint of Sextus in the modern era, 1621; Blaise Pascal 1623-1662; Pierre Bayle 1647-1706.)

Elaborating the Bass Clef Theme

It does not go without saying that the pessimism of the honest skeptic conflicts with her sincere, often ardent, desire to know truth. We are not clear how the ancient skeptics resolved this problem, for we have no intimate knowledge of their thoughts. They may have used their pessimism to advantage, securing their epoche, and with it their ataraxia, from the prospect of a dogmatic victory. But this is to take the reading that the Greek skeptics preferred ataraxia to truth. In any case in modern skeptics the conflict of this pessimism with the desire to know truth has contributed to a deep spiritual crisis.

Can the skeptic preserve her peace of mind while suspending her judgment on momentous questions such as the existence of a god, or on dogmas, like some on salvation, that make skepticism itself out to be an absolute mistake?

Losses and Gains

The larger problem in this area is that the skeptic's love of truth and desire for knowledge is sincere and intense. But her fear of error is also sincere and intense, and it apparently requires the merciless and universal application of the tropes. But this in turn leads to the pessimism that knowledge, truth, and certainty seem unattainable. This has led some commentators to say, rightly I think, that the skeptic is the seeker after absolutes. As John Owen put it, the skeptic is "the searcher who must needs find, if he finds anything, not only demonstrable and infallible, but unconditionally perfect truth."[Note 16] The tropes would demolish anything less.

The skeptic willingly acknowledges that in her long experience of inquiry she may well have suspended judgment on many truths just because they were not absolutely certain. To relax her standards to allow some occasional affirmation on strong but not conclusive grounds would undoubtedly admit many truths, but it would also admit many errors. As Pascal put it, "It is necessary to relax the mind a little, but that opens the door to the greatest excesses."[Note 17] Pyrrhoneans who pursue truth more than safety will not voluntarily relax.

This has led William James to say that in the skeptic the fear of error dominates the love of truth.[Note 18] This is virtually admitted on behalf of Academic skeptics by Cicero.[Note 19] To James this is a poor choice justified, if at all, only by the hope to cover one's losses (excluded truths) by one's gains (avoided errors). In an inquirer whose love of truth were the greater, the risk of error would be acceptable if it also meant the chance of truth. But for James the skeptic ultimately lets her fear of error prevail, and does not make the gamble. One may put a different emphasis on James' point, and say that the Pyrrhonean loves truth too much to give assent promiscuously. In this way, the so-called "fear of error" may be reinterpreted as another consequence of the love of truth and the honest high standards of inquiry.

It seems that all radical skeptics are skeptical only unwillingly, and that the more radical they are the less willing they are to remain skeptics. But their severe and rigorous code of intellectual honesty and their extraordinary love of truth and fear of error leave them no choice. A wager like Pascal's or a leap of faith like Kierkegaard's looks very inviting, especially as less sudden and more step-like transitions to belief are apparently closed to them. But these leaps are lapses to the skeptic, lapses of vigilance and critical alertness, and she cannot make them.

Irrefutable and Inescapable

This raises the most interesting question whether a radical skepticism is not only logically irrefutable but psychologically inescapable. Given her arsenal of tropes a skeptic will usually be able to find good grounds to suspend judgment on any dogma. Radical skeptics will not say for themselves (I.200, I.208, but see I.169, I.178), so I will say for them, that they will always find such grounds. Their honest and fearful deployment of the tropes to prevent their affirmation of any error at once closes off all truth to them and immunizes them to outright refutation. The only escape they see for themselves is the chance encounter with an absolutely certain truth. If we discard that possibility, the only escape is a relaxation of vigilance, a period of forgetfulness, a break in the armor of caution.[Note 20] That may happen, of course. The needs of personality do not follow the same course as the needs of inquiry. The skeptic may be taken unawares by her own self wanting to believe.

Wanting Truth (Certainty), Shunning Belief (Certitude)

But the skeptic has a legitimate fear of that ever happening. For she realizes that all firm beliefs are believed to be true even if they are false. As Peirce put it, "we think each of our beliefs to be true, and, indeed, it is a mere tautology to say so."[Note 21] She worries, in short, that certainty is a sign of foolishness.[Note 22] She realizes, or fears, that after a lapse, no matter how much easier or more tranquil her life would become, and no matter how many truths she would finally affirm, she would not be able to tell the difference between a true belief and a false belief if the beliefs were her own and firmly fixed. Once fixed, a belief will use itself to interpret the evidence, color her judgment, and structure (or filter) the rest of her experience, even if the belief is false or incomplete.[Note 23] Others may be able to tell which of our fixed beliefs are false, but to the believer they are by definition truths no longer open, or at least no longer easy, to question.

In short, certitude cures doubt, not ignorance. And with doubt conquered, ignorance is invincible.

So skeptics dread attaining mere certitude or conviction, fearing it will (or could) mask its falsehood behind their enthusiasm. The possibility of error is not overcome by merely psychological conviction; it is hidden and buried by it. The skeptic wants to know the truth with certainty. She wants to stop being a skeptic, but does not want to believe blindly. Unlike the drunkard who knows that drinking solves no problems, but reconciles one to them unsolved, the skeptic fears to become satisfied with second-best. She wants to put an end to her skepticism in such a way that the dreaded possibility of error is rooted out, known to be conquered, and answered with finality, not simply submerged and forgotten or made to seem innocuous. As Benson Mates put it, "we do not want merely to 'get over' [skepticism], whether by a natural deterioration or by some sort of therapy or 'treatment'. On the contrary, we require a more or less rational explanation of exactly where and how the skeptical train of thought goes wrong."[Note 24]

The person in whom doubt is suppressed rather than answered makes the worst sort of dogmatist. The person who disregards the possibility of error or downplays its threat is the most heedless of the challenge of skepticism, the least humble in conviction, and perhaps the most blind to possibilities of disaster —and as W.K. Clifford would add, the most immoral, the most heedless of the moral consequences of credulity.

Skepticism as Preparation for Non-Skepticism

Some commentators who think skepticism is refutable, like Descartes and Spinoza, and others who think it can be outgrown, like Nicholas of Cusa, Hume, and Margaret Wiley, say the natural escape from skepticism is dogmatism. Skepticism is a valuable preparation to good and honest commitment because it teaches impartiality, eliminates false starts, and disciplines the intellect. Deliberate use of skepticism to purge and improve or establish some dogmatism is often called methodological skepticism.

Descartes used skepticism, or something much like it, to clear the boards of all dubitable opinions in order to find one idea he could not doubt. Then he dogmatized freely on that basis of that supposed certainty. Aenesidemus believed that the skeptical position that contraries apparently inhere in objects led to the Heraclitean position that they actually inhere in objects. Similarly, Margaret Wiley believes that the skeptical practice of affirming neither of two contraries leads, through the stages of dualism and paradox, to the mystical position of affirming both (cf. I.210). Edmund Spenser and Ralph Waldo Emerson are two of her many examples. For her and Aenesidemus, skepticism is the preparation for mystical religion.[Note 25] For Joseph Glanvill and W.K. Clifford skepticism is the preparation for science. For Hegel it is the preparation for the transition from one inadequate dogma to a more adequate (but still inadequate) dogma.[Note 26] For Kant it assists dogmatic methods in solving problems.[Note 27] For many commentators on (and allies of) Socrates, skepticism is the preparation for all change and progress, for personal enlightenment and social, political, religious, and scientific revolution. For others like Bertrand Russell it is the preparation for the always useful clear head and unbiased judgment.

The question to ask these people is how to quit skepticism after starting it. I do not think skepticism will uncover a certainty that will trip it up and turn it into dogmatism. And the psychological transitions to faith are powerless so long as the skeptic is on her toes: she will always, even if reluctantly, find the grounds needed to suspend judgment on anything short of perfect certainty. And to the skeptic, to quit skepticism before or without finding certainty is simply dishonest. It is to lower one's sights, and to substitute the goal of certitude or probability for that of certainty and knowledge of truth. Hence, for the same reasons, it is liable to deception. It disregards the possibility of error, and violates the humility and honesty of genuine inquiry.

Who Cares?

Many dogmatists like to point out that this infallible, indefeasible, incorrigible, perfectly conclusive absolute certainty, which alone the skeptic could accept, is unnecessary for the purposes of inquiry, thought, action, and life. It is the overkill of doubt. Uncertainty is a matter of degree, and while extreme uncertainty would be debilitating, we can acquire sufficient certainty for confident actions that will meet all the needs that arise in experience. That we have lived this long with this relative success and without the absolute certainty the skeptic seeks is a suggestive sign that the dogmatists are right on this. But it is very important to realize that this position concedes everything to the skeptic. It is by no means a refutation of skepticsm. The dogmatist here grants all that the skeptic asks and adds only a small, "So what?"

The skeptic's response to the 'so what' is typical. She says, "You may be content with uncertainty of some degree, but I am not. Even if we can both live successful lives without perfect certainty, I never claimed that uncertainty prevented that. There is only one thing that uncertainty prevents, if we are honest with ourselves, and that is our ever claiming to know that any given idea is true. For that is precisely what is uncertain."

In short, the dogmatist may get the skeptic to admit that perfect certainty is unnecessary for life, so long as it is also admitted that certainty is necessary for the claim of knowledge. Many dogmatists have tried to deflect the skeptical challenge by maintaining that one can be correct in a judgment even if one lacks certainty. Skeptics, however, virtually admit this, and do admit it ex concessis, when they confess that they may well have suspended judgment on many truths just because they were not perfectly certain. The dogmatist has to argue, instead, that the search for truth need not be converted, as the skeptic converts it, into a search for certainty.

Fideism and Fictionalism

Just to round things out: "fideism" (from Latin fide, faith) is the usual name for the position that concedes to the skeptic the uncertainty of all —or many— claims to truth, but which observes that true ideas are no less true for being uncertain. The fideist will assert that something is true, but will not pretend to have certainty or proof. In fact, the fideist may admit that the proposition that is affirmed by faith is equipollent with its contraries. Fideists are like skeptics who love truth more they fear error, and who take the chance of affirmation.

"Fictionalism" is the name of the position that refrains from truth-assertion, usually on skeptical grounds, but which nevertheless holds and acts on ideas. It selects one idea over others not because it is supposed to be true, but because it is useful, beautiful, comforting, vital, life-affirming, or something else. The fictionalist may agree that we cannot be certain which ideas are true, but insists that we can be certain which ideas are useful, for example. They may as well be false, as far as fictionalists are concerned, so long as the ideas are used and affirmed only for the virtue recognized in them, be it beauty, utility, vitality, or solace.

Those who capitulate to skepticism but say 'so what' are usually either fideists or fictionalists. It is sometimes helpful to see skepticism, Heracliteanism, fideism, and fictionalism as different responses to uncertainty (or equipollence). When confronted with two propositions that seem to have equally strong supporting arguments, the skeptic will believe neither and continue inquiry, the Heraclitean (mystic, dialectician) will believe both, the fideist will believe just one but avoid claiming certainty, and the fictionalist will hold one, both, or neither, as the circumstances require, but will not hold them as truths. Set up this way, it is illuminating to recognize other philosophical positions as members of the family, other ways to respond to equipollence.

Pragmatism, for example, may be seen as a way to avoid the paralysis that uncertainty (or equipollence) might require under other epistemologies. When there are insufficient grounds to decide the truth of a claim using classical theories of truth, a pragmatist will experiment and hold to the claim that, in Peirce's words, "will take us where we aim at and not astray."[Note 28] This pragmatic assent may be conjoined with a suspended judgment on the truth of the claim in the classical senses of 'truth', or it may be seen as a new model of truth intended to supplant the classical models. In the former case, equipollence is a bar to claiming truth but not a bar to assent or action; in the latter it is not a bar of any kind.

Existentialism, to take one more example, may be described (from one standpoint) as the position that one's beliefs and actions are simply chosen in a state that may as well be perfect uncertainty. To claim that there are criteria to guide choice is to be subject to the skeptical dilemma to prove the criteria or leave them unproved. Either way one returns either to the original uncertainty or to one's responsibility to choose in the face of uncertainty. To say that equipollence rarely arises because evidence and arguments usually favor one side of a dispute is to forget our role in choosing the standards of evidence and argument. Hence, either we choose positions in the teeth of uncertainty, or we follow the guidance of standards that we have previously chosen. If we have positions and deny that they are chosen at one of these levels, then we are denying our freedom in bad faith.

Skepticism as it subsists concretely in skeptics, as opposed to skepticism as an abstract epistemological position, very often glides off into fideism, fictionalism, pragmatism, existentialism, or the dialectical or mystical position embracing the coincidence of opposites. This is not a refutation of skepticism, for it is a fact only of biography, not epistemology. But it leads one to ask how far skepticism itself is compatible with these neighboring positions, and how far they admit of being held simultaneously with skepticism. The answer of biography and history, if not of logic, is that they are very often compatible and very often simultaneous, mutually influential forces in the tension of a thinker's thought.

Can the Skeptic Act?

Some dogmatists go further than 'so what' in their challenge to skepticism. Some say that a successful life, even in the biological sense, is not possible without some fixed beliefs in the truth of some ideas.

Here we must make more clearly the distinction between certainty and certitude that we have been using. Certainty would be the result of an infallible and conclusive proof. It contains the notions of incorrigibility, indefeasibility, and necessity. Certitude is merely the psychological state of being convinced or persuaded, or negatively, the state of having no actual doubts or reservations. Almost by definition, certitudes may be false,[Note 29] but certainties must be true. Certainty is an 'all-or-nothing' category; either a theory is established with certainty or it is not. Certitude is a 'more-or-less' category; theories may inspire varying degrees of certitude in believers. Certainty applies to propositions and proofs, while certitude applies to persons.

Certitude and certainty are independent and can occur separately (if they can occur at all). Certitude exists without certainty whevever we believe something firmly but falsely or on insufficient grounds. But certainty could also exist without certitude, for example, for a person who did not believe that god exists (or the Pythagorean theorem) when there happened to be a definitive proof.

While many dogmatists will concede to the skeptic that certainty is unnecessary for life, many will insist that certitude is necessary. In plainer words, provable knowledge may not be necessary to live, but firm beliefs, or what Santayana called "animal faith" may be necessary.[Note 30] These dogmatists say that all action betrays the actor's faith or certitude, and that all speech betrays the speaker's faith or certitude, that something or another is the case. I could not write these words unless I had certitude that my pen was not a bomb triggered by use. I would not be writing unless I had the certitude that eyes could see and minds understand what I am saying. Nor could I say much in grammatical English without hiding an assertion of a fact or a belief. These are the two most widespread objections to skepticism, that a thorough-going skeptic must live in silent paralysis if she lives at all: she could not act or speak without either betraying a dogmatic commitment or converting herself in the deed to dogmatism. If a skeptic talks but does not say she is a dogmatist, then she is a hypocrite.

The skeptic's answer is complicated and subtle. Here I will give it briefly but without (as Cabell says) reducing to baldness what is entitled to some hair-splitting. The skeptic allows herself to give assent to those things that take it involuntarily. She has no choice. That appearances appear is not open to question, they say. It leads compulsorily to assent, as Sextus puts it (I.193; cf. I.13, I.19, I.22, I.230). What lies behind, or beyond, or beneath, appearances, however, what causes them, what the world must be like to appear in this way, what is the nature of appearances and of the appearing, all these questions are open to dispute and the skeptic suspends judgment on the proposed answers. She will admit that she sees, hears, smells, touches, and tastes, and she is even willing to describe these sensations as they appear to her at the moment. But all speculation about what underlies appearances or what does not appear, is vulnerable to the tropes and to equipollence with conflicting speculation.

(In case you think the principle of compulsory assent is subject to dogmatic abuse, it should be noted that only one dictum is ever put in this category, namely, that appearances appear. In one place, Sextus hints without being explicit that the conclusions of some arguments can be complusory in this way, II.251. Affections are involuntary, but apparently do not involve assent, I.29, I.238.)

The skeptic distinguishes thus between the evident and the non-evident, although she is not dogmatic either about the distinction or about what belongs to what side of it. (Apparently, even things in the 'evident' category may be controversial, I.185-186, or subject to epoche, II.95.) Sextus says of the evident that skeptics "yield" to it "without any consent" (I.230), a significantly different thing from dogmatic assent or assertion.

On a different level the skeptic does the same with customs, habits, and virtues that she does with appearances. Skeptics live in particular times and places, like everybody else, where particular customs and codes of conduct prevail. Just as certain appearances are given, even if they are not true, so are certain traditions and laws given, even if they are not the best ones. To preserve her peace of mind, and to avoid rash judgment about which customs are better than others, the skeptic will act the way her friends and fellow citizens act. Most skeptics, for this reason, are not overt gadflies like Socrates. However, they often have a similarly subversive effect, simply by observing that the manners and morals of their contemporaries cannot establish their superiority to those of other times and places.

Skeptics follow local custom because, personally, at the moment, they have no better rules to follow, and because gross departures seem to be attended by unwelcome perturbations. As Sextus says, "Adhering, then, to appearances we live in accordance with the normal rules of life, undogmatically, seeing that we cannot remain wholly inactive" (I.23; cf. I.226-227, I.231, II.246, III.235). The modern reader should decide whether this passage suggests a wistful regret that skeptics cannot remain wholly inactive, or a hearty appetite for an active life.

Sextus describes the four-fold regulation of life (I.23, I.237). Skeptics allow themselves to be guided by (1) the forces of nature, and (2) the feelings of the affections, both of which are beyond their control, as well as by (3) the traditions of laws and customs in their locale, and by (4) the accumulated practical wisdom on how best to accomplish certain ends. To follow one of these four guides is to 'follow appearances' and to avoid dogmatism. It is not dogmatic, then, (1') to sense sensations or think thoughts, (2') to feel hunger and act on the feeling by eating, (3') to refrain from sexual intercourse with siblings and perhaps even to attend the local church, and (4') to drink water from a cup instead of hiring a servant to wring a damp cloth into one's mouth.

Most dogmatists who object that skeptics cannot act without betraying a dogmatic belief seem to be saying little more than that all action "presupposes something". But this is not always a sign of dogmatic belief. When a skeptic acts, a dogmatic psychologist or philosopher might want draw inferences about what that act presupposes. But so will the skeptic who, as an inquirer, wants to know what she is really like. The skeptic's action may presuppose realities, but not necessarily beliefs. The act may imply that all the conditions of its possibility have been met (to speak like a Kantian for a moment), but it need not imply that the skeptic has a dogmatic belief about any of those conditions. A Pyrrhonean may say, without inconsistency, that what one does and how one appears are promising clues to what one really is. "Let us follow that clue," she might say. "What theories do you propose, or have you heard, and what are their grounds?"

If action "presupposes something", then we must ask what and how it is presupposed. (1) It might be a reality rather than a belief about a reality, as just discussed. (2) It might be assumed ex concessis by the skeptic, deliberately but as it were vicariously or histrionically. (3) It might be a case of the evident, rather than non-evident, or of involuntary rather than voluntary assent. (4) Or it might be a self-cancelling, hence non-dogmatic, dogma. (See the next section on whether skeptics can speak.) Finally, (5) it might be a dogmatic belief that the skeptic has not noticed or examined in herself. Before she is charged with hypocrisy or inconsistency, she should have a chance to judge it. As Wittgenstein put it, "[b]eing help saying such-and-such; being irresistibly inclined to say it— does not mean being forced into an assumption, or having an immediate perception or knowledge of a state of affairs."[Note 31]

Many philosophers have pointed out that human beings are raised to be dogmatists, or to believe what their parents and culture believe.[Note 32] As Nietzsche said,[Note 33]

...At bottom, every high degree of caution in making inferences and every skeptical tendency constitute a great danger for life. No living beings would have survived if the opposite tendency —to affirm rather than suspend judgment, to err and make up things rather than wait, to assent rather than negate, to pass judgment rather than to be just— had not been bred to the point where it became extraordinarily strong.

If so, then those who become Pyrrhonean later in life will want to purge themselves of their dogmatic inheritance. When dogmatists point out that Nescio "presupposes something" she will listen closely. If it is a theory, she will want to make it explicit and inquire into its merits; until she deliberately affirms it, she holds it in a non-dogmatic form. (If she "presupposes a reality" in the sense elucidated above, or if she displays the fulfillment of a series of conditions, then she will want to hear what the dogmatist thinks about it.) But from the time the Pyrrhonean finds her mission in honest inquiry, the external examination of dogmatic positions is only half her task, next to her internal skeptical purgation.

Incidentally, many dogmatic objections misfire by not taking into account that some skeptics are further along the process of purgation than others. It may well be, although Sextus gives no clue here, that the process of purification eventually removes the original desire to seek truth, inherited from Stoic or dogmatic teachers, and finally finds the value of truth to be equipollent with that of ignorance and error. This may explain the rise of fideist and fictionalist skeptics.

That the Greek skeptics did live ordinary —if austere— lives is granted. The question is whether the fourfold regulation alone permitted all the actions the skeptics performed, and whether the fourfold regulation itself is permissible to skeptics.

Paul Feyerabend calls himself an epistemological anarchist. That is the not the same thing as a Pyrrhonean skeptic, but it is near kin. His reply to the objection that epistemological anarchists cannot act applies as well to the Pyrrhonean, even if it is a defense that Nescio would not use herself. Why don't epistemological anarchists hurl themselves from 50-story windows?

The case of the window-avoiding anarchist shows that anarchists often behave in a predictable way. It does not show that they, or their fellow window-avoiders, are guided by a rationality theory, for example, that they have chosen the behaviour suggested by the most advanced research programme known to them. Kittens approaching a painted abyss draw back, even if this is the first thing they see. Their behaviour, most likely, is innate. People draw back because they were trained to stay away from windows and because they firmly believe what to most of them can only be rumours, viz. reports on the deadly effects of high falls. Even the mechanical and physiological theories which the more wordy non-jumpers might use to justify their behaviour have not yet been shown to be in agreement with the methodology of research programmes and I doubt that it will ever be possible to remedy this situation. The epistemological anarchist, on the other hand, is not obliged to behave contrary to custom. He may readily admit that he is a coward, that he cannot control his fear, and that his fear keeps him away from windows....What he does deny is that he can give reasons for his fear which agree with the standards of some rationality theory, so that he is actually acting in accordance with standards. This is the point at issue and not what he does or does not do.[Note 34]

Can the Skeptic Speak?

As to speech, the skeptics themselves listed at least three ways to talk without dogmatic assertion. The first is the simple reporting of one's state of mind at the moment, such as that one sees yellow or recalls that Socrates said such-and-such (I.4, I.19-20 etc., I.197, I.203).

The second is loose speaking (I.191, I.195, I.207; cf I.9). A skeptic will speak like the rest of us most of the time, saying for example "It is day". If somebody jumps down her throat and demands to know, very precisely, whether that is a claim to knowledge, then Nescio will back off good naturedly and say she was speaking loosely. "If you really want to know, at the moment I do not personally know whether or not it is day; let's inquire together." Arne Naess, a modern Norwegian philosopher of language, believes the skeptics' notion of loose talk is quite valid, distinct from dogmatic assertion, and a recognition of the subtleties of actual conversation centuries before its time (as if intelligent Greeks had to wait for 20th century professors to understand language). Naess believes that all dialogue moves through stages of loose and strict speaking, according to the importance the context places on detail and precision.[Note 35] Even if it is not saying much, the skeptics have modern analytic philosophy on their side for this one.

The third method of aphasia, or non-assertion, is the most interesting by far. When dogmatists ask whether skeptics know that they do not know, they are trying to make the skeptical statements self-refuting. The skeptics anticipated this and when pressed beyond loose talk made their statements self-justifying instead. To the skeptic, statements on uncertainty apply to themselves and, therefore, announce their own uncertainty and do not dogmatize (I.14-15, I.206, II.188). Sextus compares the skeptical expressions to aperient drugs (I.206, II.188), Montaigne[Note 36] compares them to rhubarb: they wash out the system and take themselves out at the last.[Note 37]

Even if it were a mere difference of perspective whether the statements are self-refuting or self-justifying, the conflict between the perspectives is balanced in isosthenia and skeptics will suspend judgment. As always, as Pascal observes, in a standoff between skepticism and dogmatism, the skeptic will win because it is a standoff.[Note 38]

There are other methods of aphasia described in Sextus Empiricus, at least by implication. One is to use terms "in an undogmatic and indeterminate sense" (I.239-240). Another is to use questions instead of statements, although skeptics do (and may) use statements (I.189). Speaking and asserting are distinguished even when no method is discussed for doing the former and avoiding the latter (I.196, I.197). Other defenses of skeptical talk have come from friends throughout history. One is that the irony with which Socrataes spoke was non-committal in the dogmatic sense, even while it was an accurate and precise tool in discourse (cf. I.221, II.42). Another is my interpretation that Pyrrhoneans speak and may speak ex concessis, a claim compatible with, but never asserted by, Sextus Empiricus. A final defense is the claim by both Voltaire and Talleyrand that language conceals thought and belief far more than it reveals them.

Note too that if skeptics are permitted to "presuppose realities" as opposed to beliefs, to follow appearances, or to yield without consent to certain affections, then that may suffice to give them a license to speak above and beyond their permission to speak loosely, ex concessis, or through self-cancellation. If the logical space between dogmatic belief and dogmatic disbelief is very large, as I think it is, not very small, then the problem of skeptical speech and action may well evaporate.

Can There Actually Be a Radical Skeptic?

The last objection to skepticism I want to discuss here is Bertrand Russell's, that "[s]cepticism, while logically impeccable, is psychologically impossible."[Note 39] The claim here is that the suspension of judgment on every non-evident matter whatsoever simply cannot be done, even if it ought to be done. This is a variation of a much older idea that we find as early as Aristotle. Pascal says that the mind naturally desires to believe, and when it cannot find truth it will attach itself to falsehood.[Note 40] Reason, he says, confutes the dogmatists by undermining all their beliefs, but Nature confutes the skeptics by forcing them to believe.[Note 41] William James says that to believe something is psychologically unavoidable, even if it is logically optional.[Note 42] F.C.S. Schiller holds that there are "vitally necessary" beliefs, very analogous to Santayana's "animal faith".[Note 43]

Hume is even more radical. He says that Nature "breaks the force of all skeptical arguments in time," even when the arguments are valid.[Note 44] Hume is persuaded by skeptics that all dogmatists are fools, but he is persuaded by Nature that skepticism cannot be taken to the limit. In a little-known remark he elects to be at least a happy and a natural fool,[Note 45] and to believe what his nature dictates.[Note 46]

For all these thinkers, belief on insufficient grounds is the inevitable result, despite the skeptic's best (and perhaps wise and justified) efforts to the contrary. There is a long tradition of dogmatic objection that charges that skepticism is simply unattainable in its most interesting or challenging forms. But Pascal, Hume, and James are here part of a sub-tradition that goes far beyond the claim that skepticism is unattainable, and that holds belief to be more 'natural' than unbelief, even to the point of asserting that unbelief cannot be sustained over long stretches of time or across broad ranges of human inquiry. Others ring variations on this tradition, such as Montaigne, who holds that belief might be optional but that those who chose to believe something just to avoid believing nothing are "stupid".[Note 47] He says incidentally that all too often dogmatism comes down to this sort of stupidity.

It is important to point out that some important observers and practitioners have said that even 'complete' skepticism is attainable: Arcesilas, Cicero,[Note 48] and, contradicting himself, as per his plan, Montaigne.[Note 49] F.C.S. Schiller holds that universal doubt is possible, but that universal disbelief is not.[Note 50]

One problem with the unattainability objection is that it is dogmatic psychology and the skeptic can suspend judgment on it. But the fideist is right that this does not mean the objection is false. More important, the skeptic can refute it by becoming a counter-example —that is, if she can. The question is a good one to leave open to further inquiry. It is important to note that the history of ideas and the biographies of philosophers sheds no light on the question: no unambiguous cases of complete skeptics are known to us. (Discussing the ambiguous cases would be fascinating but off the subject here.) If we turn instead to the psychology of the undertaking, we should realize that Descartes' pretention to have doubted everything whatesoever except that he doubted seems, on the surface of it, far more difficult psychologically than the Pyrrhonist's more modest activity of suspending judgment on all non-evident claims, neither doubting them nor forcing herself in advance to envelope the whole universe in her critique.

There is an intriguing similarity between the questions of the attainability of pure Pyrrhonism and the attainability of certainty. The spectacle of Pyrrhonean skeptics applying their tropes without mercy or prejudice might lead one to conclude that certainty was unattainable. If so, we must see Pyrrhoneans as tragic figures whose purity of heart and high standards are precisely the obstacles to the achievement of their theoretical end. We would have to conclude that only the most honest inquirers will fail, and that they will always fail. And if the sediment of human nature will always hold us back from reaching the pitch of Pyrrhonism, then those who aspire to Pyrrhonism are tragic figures in a different sense. The high standards are attainable in the sense that they may be acquired and applied. But if they are unfulfillable, then the aspirant who tries to fulfill them is striving to meet standards higher than life's own. If no dogma meets the test of the tropes, and no person can suspend judgments on all dogmas, then life itself would be second-best.

Note that if a given individual who claims to be a skeptic is caught in dogmatism, that is just her hypocrisy or inconsistency, not an objection to skepticism. To object along these lines one must show that no skeptic can avoid dogmatism.

For obvious reasons skepticism is not a doctrine or a system so much as a way of life. (Sextus calls it an agoge, a way or leading, I.4, I.209, I.212, I.232, I.235.) So its psychological possibility is at least as important as its logical coherence. I believe that radical or Pyrrhonean skepticism, like the feeling of complete hopelessness, is attainable at least in short bursts. But in any case I believe that, even if Pyrrhonean skepticism is psychologically impossible, or if never put into practice by anybody in the fullest and most thorough-going way, then the myth of the radical skeptic is as valuable as her example would have been. For the myth of the Pyrrhonean skeptic is the myth of the merciless inquirer who took intellectual honesty most seriously, who followed all leads with no prejudice, who had no respect for the authority or venerability of beliefs (or believers) and examined all for their evidence, grounds, and supporting arguments. It may be the blankness with which she begins that determines that she will find only blankness. But to keep the idea of such an inquirer before us in our own inquiries is a constant reminder against rashness, presumption, and dishonesty. The reminder is just as urgent whether radical skepticism is possible or not.

More important than this reminder is her challenge to all dogmatism —philosophical, religious, scientific, political, and the ordinary dogmatism of social life and common sense. If any dogmatism is justifiable, then we are more likely to adhere to justified dogmas if we meet the threat of skepticism head on. If the threat is too much and our beliefs fall, so much the better for us that we let it happen. The skeptic's challenge is to purge our inquiries and beliefs of bias, hasty alliances, and accidental inheritances, to overcome prejudice (literally, pre-judgment, judgment before inquiry), to examine all possibilities with sympathetic interest and critical attention, and to love truth loyally so that we may be spared the embrace of falsehood in the darkness. Only one who fears truth as much as the skeptic fears error would evade the confrontation with skepticism just because one might lose it.

The skeptic's threat to dogmatism is real. We with beliefs cannot say to the skeptic that her personal failure to find truth, so far, is just her problem. It is our problem too, for she has seen our beliefs and has found them wanting. There are ways short of perfect certainty to keep our beliefs. But there are no honest ways without critical inquiry. To admit that we might be wrong, to hold our beliefs with humility and without presumption, and to accompany all commitment with continual inquiry and open-mindedness, are the minimal lessons of skepticism.

In the face of the skeptic's barren results, the product of her extreme devotion to intellectual honesty, we should not ask what can be said for dishonesty. Instead we should ask what else besides honesty must we bring to inquiry in the beginning, and how we can get away with it. And instead of trying to protect our license to believe by refuting or ignoring skepticism, that is, by resort to impossible or dishonest means, we should ask why we esteem that license so highly. For the rest —even if we hold out hope for knowable truth— we should ask how to cope with uncertainty without completely conquering it, for this seems to be our destiny.

Works Cited

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1. Robertson at p. i.4. See the bibliography at the end of the essay for full citations of all works cited in footnotes. [Resume]

2. Pascal at L.158, B.236. [Resume]

3. See Bury's "Introduction" to his translation of Sextus Empiricus, Outlines of Pyrrhonism, at pp. xxxf; also see Mannheim at p. 9. Cioran argues, conversely, that skeptics do not reflect the turbulence of their times so much as cause it; see Cioran at pp. 76, 90, 92. [Resume]

4. References to Sextus Empiricus, Outlines of Pyrrhonism, will be kept in the text. All other works will be cited in footnotes. [Resume]

5. Plato, Apology, 21.d, 23.b, 29.d. [Resume]

6. See Montaigne, passim; Pascal, B.390. [Resume]

7. Compare Pascal, L.160, B.257; Montaigne II:12.371. [Resume]

8. Cicero at pp. 425, 453 (Socrates), 505 (Varro), 607 (Antipater), 551, 571, 581 (Cicero himself), and 503 (Cicero's dialogue character Hortensius). [Resume]

9. Cicero at pp. 453 (Arcesilas), 455, 503, 609 (Carneades), 561 (Chian Metrodorus), and 659 (Cicero's dialogue character Catalus). [Resume]

10. Seneca, Epistle 88.43, at p. 375. [Resume]

11. Cicero at pp. 491, 501, 519, 529, 543, 553, 557, 565, 573, 583, 595, 597, 651; Montaigne, at pp. II:12.374, 376, 422. [Resume]

12. Dostoevsky at p. 15. [Resume]

13. Skeptics are not the only ones who find skepticism to be more honest than dogmatism. Pausing in one of his excoriations of previous philosophers, Nietzsche says,

I exclude a few sceptics, the decent type in the history of philosophy: but the rest are ignorant of the first requirements of intellectual integrity.
Nietzsche, Anti-Christ, section 12, at p. 122. [Resume]

14. Pascal, L.405, B.421. [Resume]

15. Bayle, Dictionary, "Pyrrho", Remark B, at p. 197. [Resume]

16. Owen at p. I.vii. [Resume]

17. Pascal L.540, B.380. [Resume]

18. James at pp. 26, 94.n. [Resume]

19. Cicero at pp. 453, 551, 553, 631, 647. [Resume]

20. Hume, Treatise at p. 218. [Resume]

21. Peirce at p. 13. [Resume]

22. Montaigne, II:12.404: "The impression of certainty is a certain token of folly and extreme uncertainty." Also see Hume, Treatise, at 218, 269. Wittgenstein in On Certainty, argued, on the contrary, that certainty is not always stupid; see sections 150, 344, 358, and esp. 235. [Resume]

23. Montaigne at p. II:12.327; Clifford at pp. 28-29. [Resume]

24. Mates at p. 21. [Resume]

25. see also Pascal, L.177, L.404, L.519, L.536, L.576, L.619, L.681, L.691, L.786. [Resume]

26. Hegel at pp. 49, 50, 124f. [Resume]

27. Kant at B.451-52, B.535. [Resume]

28. Peirce at pp. 9, 30. [Resume]

29. See Montaigne at p. II:12.423. [Resume]

30. For an assessment of the "survival value" of belief, and of truth, see F.C.S. Schiller, Chapters XI and XII. [Resume]

31. Wittgenstein, Investigations, section 299. [Resume]

32. Cicero at p. II.iii.8; Montaigne at p. II:12.373, cf. 325. [Resume]

33. Nietzsche, Gay Science, section 111. [Resume]

34. Feyerabend at pp. 221-222. [Resume]

35. Naess at pp. 10-11, 113-16, 122. [Resume]

36. Montaigne at II:12.392-393. [Resume]

37. Compare Hume, Treatise at pp. 186-187. [Resume]

38. Pascal at L.131, B.434. [Resume]

39. Russell at p. 9; cf. 196. [Resume]

40. Pascal at L.661, B.81. [Resume]

41. Pascal at L.131, B.434; cf. Bayle, "Pyrrho", Remark C, at p. 205. [Resume]

42. James at pp. 4, 9-11, 14, 21. [Resume]

43. F.C.S. Schiller at p. 33. [Resume]

44. Hume, Treatise at p. 187, cf. 269; and Enquiry at p. 160. On the general position that total skepticism cannot be lived, see the Treatise at 116, 214, 254. [Resume]

45. Hume, Treatise at p. 270. [Resume]

46. See Santayana at p. 308. [Resume]

47. Montaigne at p. II:12.373. [Resume]

48. Cicero at pp. 563-65 (Arcesilas) and 607 (Cicero himself). [Resume]

49. Montaigne at p. II:12.374. [Resume]

50. F.C.S. Schiller at pp. 25ff. [Resume]

Ribbon] Peter Suber, Department of Philosophy, Earlham College, Richmond, Indiana, 47374, U.S.A. Copyright © 1996, Peter Suber.