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| History of Skepticism |
Skepticism (also spelled “Scepticism”) is the philosophical attitude of doubting knowledge claims set forth in various areas. Skeptics have challenged the adequacy or reliability of these claims by asking what they are based upon or what they actually establish. They have raised the question whether such claims about the world are either indubitable or necessarily true, and they have challenged the alleged grounds of accepted assumptions.
Practically everyone is skeptical about some knowledge claims; but the skeptics have raised doubts about any knowledge beyond the contents of directly felt experience. The original Greek meaning of skeptikos was “an inquirer,” someone who was unsatisfied and still looking for truth.
From ancient times onward skeptics have developed arguments to undermine the contentions of dogmatic philosophers, scientists, and theologians. The skeptical arguments and their employment against various forms of dogmatism have played an important role in shaping both the problems and the solutions offered in the course of western philosophy.
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| skeptikos |
As ancient philosophy and science developed, doubts arose about basic accepted views of the world. In ancient times skeptics challenged the claims of Platonism, Aristotelianism, and Stoicism, and in the Renaissance those of Scholasticism and Calvinism. After René Descartes, skeptics attacked Cartesianism and other theories justifying the “new science.”
Later, a skeptical offensive was leveled against Kantianism and then against Hegelianism. Each skeptical challenge led to new attempts to resolve the difficulties. Skepticism, especially since the Enlightenment, has come to mean disbelief— primarily religious disbelief—and the skeptic has often been likened to the village atheist.
Various Senses and Applications
Skepticism developed with regard to various disciplines in which men claimed to have knowledge. It was questioned, for example, whether one could gain any certain knowledge in metaphysics (the study of the nature and significance of being as such) or in the sciences. In ancient times a chief form was medical skepticism, which questioned whether one could know with certainty either the causes or cures of diseases.
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| Various Senses and Applications |
In the area of ethics, doubts were raised about accepting various mores and customs and about claiming any objective basis for making value distinctions. Skepticisms about religion have questioned the doctrines of different traditions.
Certain philosophies, like those of David Hume and Immanuel Kant, have seemed to show that no knowledge can be gained beyond the world of experience and that one cannot discover the causes of phenomena. Any attempt to do so, as Kant argued, leads to antinomies, contradictory knowledge claims.
A dominant form of skepticism, the subject of this article, concerns knowledge in general, questioning whether anything actually can be known with complete or adequate certainty. This type is called epistemological skepticism.
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| René Descartes |
Kinds of epistemological skepticism can be distinguished in terms of the areas in which doubts are raised; that is, whether they be directed toward reason, toward the senses, or toward knowledge of things-in-themselves.
They can also be distinguished in terms of the motivation of the skeptic—whether he or she is challenging views for ideological reasons or for pragmatic or practical ones to attain certain psychological goals. Among the chief ideological motives have been religious or antireligious concerns. Some skeptics have challenged knowledge claims so that religious ones could be substituted—on faith.
Others have challenged religious knowledge claims in order to overthrow some orthodoxy. Kinds of skepticism also can be distinguished in terms of how restricted or how thoroughgoing they are—whether they apply only to certain areas and to certain kinds of knowledge claims or whether they are more general and universal.
Ancient Skepticism
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| Ancient Skepticism |
Historically, skeptical philosophical attitudes began to appear in pre-Socratic thought. In the fifth century BCE, the Eleatic philosophers, known for reducing reality to a static One, questioned the reality of the sensory world, of change and plurality, and denied that reality could be described in the categories of ordinary experience.
On the other hand, the Ephesian philosopher of change Heraclites and his pupil Cratylus thought that the world was in such a state of flux that no permanent, unchangeable truth about it could be found; and Xenophanes, a wandering poet and philosopher, doubted whether man could distinguish true from false knowledge.
A more developed skepticism appeared in some of Socrates’ views and in several of the Sophists. Socrates, in the early Platonic dialogues, was always questioning the knowledge claims of others; and in the Apology, he said that all that he really knew was that he knew nothing. Socrates’ enemy, the Sophist Protagoras, contended that man is the measure of all things.
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| Ephesian |
This thesis was taken as a kind of skeptical relativism: no views are ultimately true, but each is merely one man’s opinion. Another Sophist, Gorgias, advanced the skeptical-nihilist thesis that nothing exists; and if something did exist, it could not be known; and if it could be known, it could not be communicated.
ACADEMIC SKEPTICISM. Academic skepticism, socalled because it was formulated in the Platonic Academy in the third century BCE, developed from the Socratic observation, “All I know is that I know nothing.”
Its theoretical formulation is attributed to Arcesilas (c. 315–241 BCE) and Carneades (c. 213–129 BCE), who worked out a series of arguments, directed primarily against the knowledge claims of the Stoic philosophers, to show that nothing could be known.
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| Arcesilas |
As these arguments have come down to us, especially in the writings of Cicero, Diogenes Laertius, and Saint Augustine, the aim of the Academic skeptical philosophers was to show, by a group of arguments and dialectical puzzles, that the dogmatic philosopher (that is, the philosopher who asserted that he knew some truth about the real nature of things), could not know with absolute certainty the propositions he said he knew.
The Academics formulated a series of difficulties to show that the information we gain by means of our senses may be unreliable, that we cannot be certain that our reasoning is reliable, and that we possess no guaranteed criterion or standard for determining which of our judgments is true or false.
The basic problem at issue is that any proposition purporting to assert some knowledge about the world contains some claims that go beyond the merely empirical reports about what appears to us to be the case.
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| Diogenes Laertius |
If we possessed any knowledge, this would mean for the skeptics, that we knew a proposition, asserting some nonempirical, or trans-empirical claim, which we were certain could not possibly be false. If the proposition might be false, then it would not deserve the name of knowledge, but only that of opinion, i.e., that it might be the case.
Since the evidence for any such proposition would be based, according to the skeptics, on either sense information or reasoning, and both of these sources are unreliable to some degree, and no guaranteed or ultimate criterion of true knowledge exists, or is known, there is always some doubt that any non-empirical or transempirical proposition is absolutely true and hence constitutes real knowledge. As a result, the Academic skeptics said that nothing is certain.
The best information we can gain is only probable and is to be judged according to probabilities. Hence, Carneades developed a type of verification theory and a type of probabilism that is somewhat similar to the theory of scientific ‘”knowledge” of present-day pragmatists and positivists.
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| Antiochus of Ascalon |
The skepticism of Arcesilas and Carneades dominated the philosophy of the Platonic Academy until the first century before Christ. In the period of Cicero’s studies, the Academy changed from skepticism to the eclecticism of Philo of Larissa and Antiochus of Ascalon.
The arguments of the Academics survived mainly through Cicero’s presentation of them in his Academica and De Natura Deorum, and through their refutation in St. Augustine’s Contra Academicos, as well as in the summary given by Diogenes Laertius. The locus of skeptical activity, however, moved from the Academy to the school of the Pyrrhonian skeptics, which was probably associated with the Methodic school of medicine in Alexandria.
THE PYRRHONIAN SCHOOL. The putative father of Greek skepticism is Pyrrho of Elis (c. 360–c. 272 BCE) and his student Timon (c. 315–225 BCE). He avoided committing himself to any views about what was actually going on and acted only according to appearances. In this way he sought happiness or at least mental peace.
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| Saint Augustine |
The stories about Pyrrho that are reported indicate that he was not a theoretician, but rather a living example of the complete doubter, the man who would not commit himself to any judgment that went beyond what seemed to be the case.
His interests seem to have been primarily ethical and moral, and in this area he tried to avoid unhappiness that might be due to the acceptance of value theories and to judging according to them. If such value theories were to any degree doubtful, accepting them and using them could only lead to mental anguish.
Pyrrhonism, as a theoretical formulation of skepticism, is attributed to Aenesidemus (c. 100–40 BCE). The Pyrrhonists considered that both the Dogmatists and the Academics asserted too much, one group saying, “Something can be known,” the other that “Nothing can be known.” Instead, the Pyrrhonians proposed to suspend judgment on all questions on which there seemed to be conflicting evidence, including the question whether or not something could be known.
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| Aenesidemus |
Building on the type of arguments developed by Arcesilas and Carneades, Aenesidemus and his successors put together a series of “Tropes” or ways of proceeding to bring about suspense of judgment on various questions.
In the sole surviving texts from the Pyrrhonian movement, those of Sextus Empiricus, these are presented in groups of ten, eight, five, and two tropes, each set offering reasons why one should suspend judgment about knowledge claims that go beyond appearances.
The Pyrrhonian skeptics tried to avoid committing themselves on any and all questions, even as to whether their arguments were sound. Skepticism for them was an ability, or mental attitude, for opposing evidence both pro and con on any question about what was nonevident, so that one would suspend judgment on the question.
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| Sextus Empiricus |
This state of mind then led to a state of ataraxia, quietude, or unperturbedness, in which the skeptic was no longer concerned or worried about matters beyond appearances. Skepticism was a cure for the disease called Dogmatism or rashness.
But, unlike Academic skepticism, which came to a negative dogmatic conclusion from its doubts, Pyrrhonian skepticism made no such assertion, merely saying that skepticism is a purge that eliminates everything including itself.
The Pyrrhonist, then, lives undogmatically, following his natural inclinations, the appearances of which he is aware, and the laws and customs of his society, without ever committing himself to any judgment about them.
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| Adversus mathematicos |
The Pyrrhonian movement flourished up to about 200 CE, the approximate date of Sextus Empiricus, and flourished mainly in the medical community around Alexandria as an antidote to the dogmatic theories, positive and negative, of other medical groups.
The position has come down to us principally in the writings of Sextus Empiricus in his Hypotyposes (Outlines of Pyrrhonism) and the larger Adversus mathematicos, in which all sorts of disciplines from logic and mathematics to astrology and grammar are subjected to skeptical devastation. In his Outlines of Pyrrhonism and Adversus mathematicos, Sextus presented the tropes developed by previous Pyrrhonists.
The ten tropes attributed to Aenesidemus showed the difficulties to be encountered in ascertaining the truth or reliability of judgments based on sense information, owing to the variability and differences of human and animal perceptions.
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| Carneades |
Other arguments raised difficulties in determining whether there are any reliable criteria or standards—logical, rational, or otherwise—for judging whether anything is true or false. To settle any disagreement, a criterion seems to be required. Any purported criterion, however, would appear to be based on another criterion, thus requiring an infinite regress of criteria, or else it would be based upon itself, which would be circular.
Sextus offered arguments to challenge any claims of dogmatic philosophers to know more than what is evident; and in so doing he presented in one form or another practically all of the skeptical arguments that have ever appeared in subsequent philosophy.
Sextus said that his arguments were aimed at leading people to a state of ataraxia (unperturbability). People who thought that they could know reality were constantly disturbed and frustrated. If they could be led to suspend judgment, however, they would find peace of mind.
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| state of ataraxia |
In this state of suspension they would neither affirm nor deny the possibility of knowledge but would remain peaceful, still waiting to see what might develop. The Pyrrhonist did not become inactive in this state of suspense but lived undogmatically according to appearances, customs, and natural inclinations.
Medieval Skepticism
Pyrrhonism ended as a philosophical movement in the late Roman Empire, as religious concerns became paramount. In the Christian Middle Ages the main surviving form of skepticism was the Academic, described in St. Augustine’s Contra academicos.
Augustine, before his conversion, had found Cicero’s views attractive and had overcome them only through revelation.With faith, he could seek understanding. Augustine’s account of skepticism and his answer to it provided the basis for medieval discussions.
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| Medieval Skepticism |
In Islamic Spain, where there was more contact with ancient learning, a form of antirational skepticism developed among Muslim and Jewish theologians. Al-Ghazali, an Arab theologian of the eleventh and early twelfth centuries, and his Jewish contemporary Judah ha-Levi (c. 1075/c. 1085–c. 1141), who was a poet and physician as well as a philosopher, offered skeptical challenges (much like those later employed by the occasionalist Nicolas Malebranche and by David Hume) against the contemporary Aristotelians in order to lead people to accept religious truths in mystical faith.
This view that truth in religion is ultimately based on faith rather than on reasoning or evidence—what is known as fideism—also appears in the late Middle Ages in the German cardinal and philosopher Nicolaus of Cusa’s advocacy of learned ignorance as the way to religious knowledge.
Another line of thinking that includes skeptical elements was that of the followers of William of Ockham (1285–1347) in the fourteenth century, who were exploring the consequences of accepting divine omnipotence and a divine source for all knowledge. They examined puzzles about whether God could deceive mankind, regardless of the evidence, and could make all human reasoning open to question.
Modern Skepticism
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| Modern Skepticism |
Modern Skepticism emerged in part from some of the Ockhamite views but mainly from the rediscovery of the skeptical classics. Very little of the Pyrrhonnian tradition had been known in the Middle Ages, but in the fifteenth century the texts of Sextus Empiricus in Greek were brought from the Byzantine Empire into Italy.
Sextus’ Outlines of Pyrrhonism was published in Latin in 1562, his Adversus matematicos in 1569, and the Greek texts of both in 1621. Interest in Cicero was revived and his Academica and De natura deorum were also published in the sixteenth century.
The voyages of exploration; the humanistic rediscovery of the learning of ancient Greece, Rome, and Palestine; and the new science—all combined to undermine confidence in man’s accepted picture of the world. The religious controversy between the Protestants and Catholics raised fundamental epistemological issues about the bases and criteria of religious knowledge.
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| Nicolas Malebranche |
RENAISSANCE AND REFORMATION. Toward the end of the fifteenth century, there was a revival of interest in ancient skepticism among Florentine humanists. Politian was lecturing on philosophy using notes from Sextus with which he had recently become acquainted from manuscripts brought from Byzantium.
Humanists, including Gianfrancesco Pico della Mirandola, were acquiring and studying Sextus’ texts. Some of these manuscripts were deposited in the convent of San Marco where the Dominican friar and prophet Girolamo Savonarola was heading up an exciting intellectual forum in which ancient philosophies were being analyzed.
Savonarola, who did not read Greek, asked two of his monks to prepare a Latin translation of Sextus from one of these manuscripts. This apparently was to be used as a weapon against philosophy independent of religion. Before Savonarola’s project could be completed the convent was destroyed and he was executed.
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| Gianfrancesco Pico della Mirandola |
Gianfrancesco Pico, one of Savonarola’s disciples and the nephew of the great Pico della Mirandola, published the first work using skepticism as a way of challenging all of philosophy. Gianfrancesco Pico’s Examen Vanitatis (1520) is the first work to present Sextus in Latin for the European audience.
In 1562 Henri Estienne (Stephanus) published a Latin translation of the Pyrrhoniarum Hypotyposes in Paris, and in 1569 Gentian Hervet published a Latin translation of Adversus Mathematicos in Antwerp. The Greek texts were first printed at Cologne, Paris, and Geneva in 1621. Some texts of Sextus appeared in English in 1592 in a work attributed to Sir Walter Raleigh titled “The Skepticke.”
A full translation of Book One of Sextus appeared in 1659 in Thomas Stanley’s History of Philosophy; instead of explaining skepticism he just presented the whole book to the readers. A French translation was started by Pierre Gassendi’s disciple Samuel Sorbière but was never finished or published. The first complete French translation, by Claude Huart, did not appear until 1725.
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| Henri Estienne |
RELIGIOUS CONTROVERSY: ERASMUS AND LUTHER. The skeptical issue became more central when raised in the debate between Erasmus and Martin Luther. Using Academic skeptical materials, Erasmus insisted that the issues in dispute could not be resolved and that one should therefore suspend judgment and remain with the church. In 1524, Erasmus finally published a work, De Libero Arbitrio, attacking Martin Luther’s views on free will.
Erasmus’ general anti-intellectualism and dislike of rational theological discussions led him to suggest a kind of skeptical basis for remaining within the Catholic Church. This contempt for intellectual endeavor was coupled with his advocacy of a simple, non-theological Christian piety.
Theological controversies were not Erasmus’ meat, and he states that he would prefer to follow the attitude of the skeptics and suspend judgment, especially where the inviolable authority of Scripture and the decrees of the Church permit. He says he is perfectly willing to submit to the decrees, whether or not he understands them or the reasons for them.
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| Erasmus |
Scripture is not as clear as Martin Luther would have us believe, and there are some places that are just too shadowy for human beings to penetrate. Theologians have argued and argued the question without end. Luther claims he has found the right answer and has understood Scripture correctly. But how can we tell that he really has? Other interpretations can be given that seem much better than Martin Luther’s.
In view of the difficulty in establishing the true meaning of Scripture concerning the problem of free will,why not accept the traditional solution offered by the Church? Why start such a fuss over something one cannot know with any certainty? For Erasmus, what is important is a simple, basic, Christian piety, a Christian spirit.
The rest, the superstructure of the essential belief, is too complex for a man to judge. Hence it is easier to rest in a skeptical attitude, and accept the age-old wisdom of the Church on these matters, than to try to understand and judge for oneself.
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| Martin Luther |
This attempt, early in the Reformation, at a skeptical “justification” of the Catholic rule of faith brought forth a furious answer from Martin Luther, the De Servo Arbitrio of 1525. Erasmus’ book, Martin Luther declared, was shameful and shocking, the more so since it was written so well and with so much eloquence. De Libero Arbitrio begins with the announcement that the problem of the freedom of the will is one of the most involved of labyrinths.
The central error of Erasmus’ book, according to Luther, was that Erasmus did not realize that a Christian cannot be a skeptic. Christianity involves the affirmation of certain truths because one’s conscience is completely convinced of their veracity.
The content of religious knowledge, according to Luther, is far too important to be taken on trust. One must be absolutely certain of its truth. Hence, Christianity is the complete denial of skepticism. To find the truths, one only has to consult Scripture.
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| Counter-Reformation |
Of course there are parts that are hard to understand, and there are things about God that we do not, and perhaps shall not, know. But this does not mean that we cannot find the truth in Scripture.
The central religious truth can be found in clear and evident terms, and these clarify the more obscure ones. However, if many things remain obscure to some people, it is not the fault of Scripture, but of the blindness of those who have no desire to know the revealed truths.
Luther’s view, and later that of Calvin, proposed a new criterion—that of inner experience— while the Catholics of the Counter-Reformation employed Pyrrhonian and Academic arguments to undermine the criterion.
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| H. C. Agrippa von Nettesheim |
Following after Erasmus, H. C. Agrippa von Nettesheim, a stormy occult philosopher and physician, employed the skeptical arguments against Scholasticism, Renaissance Naturalism, and many other views to win people to the “true religion.”
HERVET. Gentian Hervet, secretary to the Cardinal of Lorraine, and participant at part of the Council of Trent, linked his work on Sextus with what Gianfrancesco Pico had earlier done. During the 1560s, Gentian Hervet, a humanist, fought intellectually against the encroachments of Calvinism, challenging various Protestants to debate with him, and publishing many pamphlets against their views.
Gentian Hervet saw Sextus’ work as ideal for demolishing this new form of heretical dogmatism, that of the Reformer. If nothing can be known, then, he insisted, Calvinism cannot be known. The only certainty we can have is God’s Revelation. Skepticism, by controverting all human theories, will cure people from dogmatism, give them humility, and prepare them to accept the doctrine of Christ.
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| Gentian Hervet |
Gentian Hervet’s employment of Pyrrhonism against Calvinism was soon to be shaped into a skeptical machine of war for use by the Counter-Reformation. This view of Pyrrhonism, by one of the leaders of French Catholicism, was to set the direction of one of its major influences on the next three-quarters of a century.
MONTAIGNE AND SANCHES. The new concern with skepticism was given a general philosophical formulation by Michel de Montaigne and his cousin Francisco Sanches. Michel de Montaigne was the most significant figure in the sixteenth century revival of ancient skepticism.
Not only was he the best writer and thinker of those who were interested in the ideas of the Academics and Pyrrhonians, but he was also the one who felt most fully the impact of the Pyrrhonian arguments of complete doubt—and its relevance to the religious debates of the time.
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| Francisco Sanches |
Montaigne was simultaneously a creature of the Renaissance and the Reformation. He was a thoroughgoing humanist, with a vast interest in, and concern with, the ideas and values of Greece and Rome, and their application to the lives of men in the rapidly changing world of sixteenth-century France.
Montaigne was sent to the Collège de Guyenne in 1539 when he was six years old and was there for the next seven years. The college reflected the religious tensions of the time. Two of its leaders were André de Gouvea, a Portuguese New Christian, and George Buchanan, the Scottish Latin poet.
Montaigne’s 1576 essay “Apologie of Raimond Sebond” unfolds in his inimitable rambling style as a series of waves of skepticism, with occasional pauses to consider and digest various levels of doubt, but with the overriding theme an advocacy of a new form of fideism— Catholic Pyrrhonism.
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| George Buchanan |
The essay begins with a probably inaccurate account of how Montaigne came to read and translate the audacious work of the fifteenth century Spanish theologian, Raimond Sebond. Starting from a quibble about the validity of the arguments of Sebond, Montaigne moved to a general skeptical critique of the possibility of human beings understanding anything.
In a rather back-handed manner, Montaigne excuses Sebond’s theological rationalism by saying that although he, Montaigne, is not versed in theology, it is his view that religion is based solely on faith given to us by the Grace of God; true religion can only be based on faith, and any human foundation for religion is too weak to support divine knowledge. If human beings had the real light of faith, then human means, like the arguments of Sebond, might be of use.
Montaigne explored the human epistemological situation and showed that man’s knowledge claims in all areas were extremely dubious and so made pure faith the cornerstone of religion. Montaigne recommended living according to nature and custom and accepting whatever God reveals.
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| Raimond Sebond |
Sanches, in Quod nihil scitur, also written in 1576, advocated recognizing that nothing can be known and then trying to gain what limited information one can through empirical scientific means. In his book, Sanches develops his skepticism by means of an intellectual critique of Aristotelianism, rather than by an appeal to the history of human stupidity and the variety and contrariety of previous theories.
Sanches begins by asserting that he does not even know if he knows nothing. Then he proceeds, step by step, to analyze the Aristotelian conception of knowledge to show why this is the case.