SKEPTICISM – RICHARD H. POPKIN
Verbete da “The Encyclopedia of Philosophy” – Paul Edward, Editor in Chief. vol VII. Collier Macmillan Publishers, London.
SKEPTICISM,
as a critical philosophical attitude, questions the reliability of the
knowledge claims raised by philosophers and others. Originally the Creek term skeptikos
meant "inquirers." Philosophical skeptics have been engaged in
inquiry into alleged human achievements in different fields lo see if any
knowledge has been or could be gained by them. They have questioned whether
any-necessary or indubitable information can actually be gained about the real
nature of things. Skeptics have organized their questioning into systematic
sets of arguments aimed at raising doubts. Extreme skepticism questions all
knowledge claims that go beyond immediate experience, except perhaps those of
logic and mathematics. A limited or mitigated skepticism in different degrees
questions particular types of knowledge claims made by theologians,
metaphysicians, scientists, or mathematicians which go beyond experience, but
it admits some limited probabilistic
kinds of knowledge. Some skeptics have held that no knowledge beyond immediate
experience is possible, while others have doubted whether even this much could
definitely be known. The arguments advanced by skeptics from Greek times
onward, and the use to which these arguments have been put, have helped to
shape both the problems dealt with by the major Western philosophers and the
solutions they have offered.
HISTORY OF SKEPTICISM
Skeptical tendencies appear in some pre-Socratic views. The metaphysical
theory of Heraclitus that everything is in flux and that one can’t step twice
into the same river was taken as indicating human inability to discover any
fixed, immutable truth about reality. The purported development of this theory
by Cratylus to the view that since everything is changing, one can’t step once
into the same river, because both that river and oneself are changing, leads
to a broader skepticism. Cratylus apparently became convinced that
communication was impossible because, since the speaker, the auditor, and the
words were changing, whatever meaning might have been intended by the words
would be altered by the time they were heard. Therefore, Cratylus is supposed
to have refused to discuss anything and only to have wiggled his finger when
somebody said something, to indicate that lie had heard something but that it
would be pointless to reply, since everything was changing.
Xenophanes questioned the existence of any criterion of true knowledge
in his observation that if, by chance, a man came across the truth, be would be
unable to distinguish it from error.
More serious skeptical doubts were raised by some of the Sophists.
Gorgias is reported to have doubted whether anything exists, and to have
offered an argument that if anything did happen to exist, we could not know it;
and if we did know it, wc could not communicate it.
The relativism involved in the famous saying of the great Sophist
Protagoras, "Man is the measure of all things," indicates another
skeptical tendency. Plato’s discussion of Protagoras’ view shows that it was
taken as a denial that there is absolutely true knowledge, and that each man’s
views are equally valid versions of what is going on. No further standards of
judgment exist.
Academic skepticism- Although Pyrrho, from whom the Pyrrhonians get
their name, lived before the major Academic skeptics, skepticism as a
philosophical methodology was first formulated by the leaders of Plato’s
Academy in the third century’ B.C. Beginning with Arcesilaus (c. 315-c. 240 bc), the Academics rejected Plato’s
metaphysical and mystical doctrines. Instead they concentrated on what they
thought was involved in the Socratic remark "All that I know is that I
know nothing," and on the questioning method and tactics of Socrates as
portrayed in the Platonic dialogues. Although we do not possess the writings of
Arcesilaus, or of the reputed greatest member of the school, Carneades (c.
213-128 B.C.), later writings by Cicero, Sextus Empiricus, and Diogenes
Laertius give a fairly good idea of the kinds of arguments they developed. The
attack of Arcesilaus was directed primarily against the Stoics, and that of Cameades against both#the
Epicureans and Stoics. The Stoics had claimed that there were some perceptions
which could not possibly be false either per se
or as signs of the true nature of reality. Arcesilaus and Carneades pointed out
that there was no criterion for distinguishing a perception of this kind from
one that appeared to be so, or was thought to be so. Cameades insisted that
there were no intrinsic marks or signs which these so-called real perceptions
possessed and which illusory ones did not, and that no justifiable criterion
existed for separating one type from the other. Therefore, he contended, we
must suspend judgment about whether reliable representations of objects
actually exist. This state of affairs, the Academics maintained, showed that no
assertions about what is going on beyond our immediate experience are certain.
The best data that we can acquire, they said, only tell us what is reasonable
or probable, but not what is true. Carneades seems to have developed a
verification theory and a probabilistic view resembling those of
twentieth-century pragmatists and positivists. The view attributed to Carneades
thus constituted a kind of mitigated skepticism.
The
Academic skeptics dominated the Platonic Academy until the first century B.C.,
when, during the period that Cicero studied there, it was taken over by the
eclectic philosophers Philo of Larissa and Antiochus of Ascalon. Cicero’s De
Academica and De Natura Deorum describe both the traditional
skeptical views and those of the newer teachers. St. Augustine’s Contra
Academicos was an attempt to answer the skepticism described by Cicero.
The
Pyrrhonian school. In the Roman period, the main center of skeptical activity
shifted from the Academy to the Pyrrhonian school, probably connected with the
methodic school of medicine at Alexandria. The Pyrrhonians attributed their
origins to the views of Pyrrho of Elis (c. 360-c. 270 B.c;.). Pyrrho left no
writings but was, rather, the model of the skeptical way of life. The stories
about him indicate that he tried to avoid committing himself to doctrines
about the nature of reality while living according to appearances and
attempting to attain happiness, or at least peace of mind. His student Timon
(c. 320-c. 230 B.C.) attacked a great many views, including those of the Academic
skeptics, mainly by satire while developing a practical, moral way of living according to human necessities
without making any grandiose commitments or claims.
Pyrrhonism, as a theoretical formulation of skepticism rather than
merely an emulation of Pyrrho, is supposed to have begun with Aenesidemus, who
probably taught in Alexandria in the first century B.C. He is reported to have
attacked both the Academics and the dogmatic philosophers; the Academics
because they were sure that what is probable and what is improbable are
distinguishable, and the dogmatic philosophers because they thought they had
discovered the truth. Aenesidemus and his successors, using the achievements of
the Academics, developed "tropes," or ways of carrying on skeptical
argumentation in order to produce epoche (suspension of judgment) about
matters dealing with what is nonevident. The fullest presentation of this type
of skepticism that we possess is that of Sextos Empiricus (second or third
century), one of the last Pyrrhonian teachers. In his Pyrrhoniarum
Hypotyposes and Advcrsus Mathematicos, Sextus set forth the Pyrrhonian
tropes in groupings of ten, eight, five, and two, each set indicating why one
should suspend judgment about all claims to knowledge extending beyond immediate
experience. The most famous of these sets was the ten tropes (attributed to
Aenesidemus). The first four of these ten deal with contradictions involved in
trying to perceive the real nature of things. Animals’ perceive things
differently; different men perceive things differently; man’s senses perceive
the same object in various ways; and man’s circumstances also seem to alter
what he perceives. Have we any way of being sure that man, and not some other
animal, perceives the world correctly? And have we any way of telling which
men, or which of our senses, or under what circumstances we are able to,
perceive the true nature of things? Others of the ten tropes suggest that the
object may be difficult or impossible to perceive correctly because it or our
perceiving organs change or are affected by circumstances, frequency of
occurrence, or customs of the society in which the observations take place.
In
further analyses, Sextus brought forth Pyrrhonian arguments to cast doubt on
any claims by dogmatic philosophers to have gained knowledge of the naturally
nonevident world (that is, of any reality tnat is not now being, and cannot at
some time be, observed). Any criterion, such as logical inference or presumed
causal connection, used to judge what is naturally nonevident can be challenged
by asking if the criterion itself is evident. The fact that there are disputes
about everything that is not observable shows that it is not obvious what
criterion should be adopted. The dogmatist is faced either with begging the
question by using a questionable criterion to establish the standard of what is
true, or with an infinite regress involving finding a criterion for judging
his criterion, and a criterion for this, and so on. In attacking the various
forms of the dogmatic claim to know what is nonevident, Sextus presented fully
developed or in embryo almost all of the arguments to appear later in the
history of skepticism. Sextus also presented a battery of Pyrrhonian arguments
against the Stoic contention that there are indicative signs in experience
that indubitably reveal what is the case beyond experience.
The point in all this argumentation, Sextus stated, was to lead mankind
to the Pyrrhonian goal of ataraxia (unperturbedness). As long as people
try to judge beyond appearances and to gain knowledge in the dogmatist’s
Sense, they will be frustrated and worried. By setting forth the evidence pro
and con, without even judging if it is good or satisfactory evidence, they will
be led to suspension of judgment and peace of mind, and thereby will be cured
of the dogmatist’s disease, rashness.
Sextus
reported (he carefully avoided saying that he asserted anything) that the
Pyrrhonians did not hold to the negative dogmatic conclusions of the Academics,
in that they did not deny that knowledge of the nonevident was possible.
Instead, they suspended judgment on the question. In response to opponents who
tried to portray the Pyrrhonian attitude as a definite view, Sextus said that
it was like a purge that eliminates everything, including itself.
The Pyrrhonians replied to the charge that their attitude would make
living impossible by stating that they were not in any way doubting the world
of appearances, and that one could live peacefully and undogmatieally in that
world by following natural inclinations (without judging that they were right
or wrong) and experience and what it suggests, in terms of patterns (what the
Pyrrhonians called "suggestive signs") and the laws and
customs of society.
The
Pyrrhonian movement continued until the third century as both a philosophical
and a medical one (medical skeptics cast doubt both on the claim that diseases
have causes and on its denial). It questioned theories in physics, logic,
mathematics, astrology, grammar, and other disciplines. The movement died out
in the late Hellenistic period and had little influence thereafter as religious
views became predominant.
The
medieval period. As the
Roman Empire became Christianized, the major remaining indication of skeptical
influence was St. Augustine’s discussion of Academic skepticism. His Contra
Academicos was the last major attempt before the Renaissance to come to
grips with skeptical questions in epistemology. Augustine was strongly
attracted to Cicero’s views and to the Platonism of the Middle Academy. Part of the resolution of his personal religious crisis was his realization, presented
in Contra Academicos and other early writings, that skepticism can be
completely overcome only by revelation. From this standpoint philosophy
becomes faith seeking understanding.
In
the Christian Middle Ages it was mainly Augustine’s version of, and his answer
to, skepticism that was discussed. Two medieval Latin translations of Sextus
exist, one from the late thirteenth century and the other at least a century
later, but there is no evidence that they were at all widely read or taken
seriously.
In the Islamic world,
where there was more direct access to classical writings, there are more
indications of skeptical currents, especially among the more extreme
antirational Spanish Muslim and Jewish theologians. The arguments of al-Chazali
and Yehuda Halevi against the possibility of rational scientific and
theological knowledge about the real nature of the universe, and especially
against the claims of the Aristotelians of the period, are often very’ similar
to classical Academic and Pyrrhonian attacks. (And al-Ghazali’s skeptical
rejection of rational knowledge of necessary connections in the world is
very-close to that of Malebranche and Hume.) However, the use made of
skepticism by Arabic and Jewish authors was radically different from that of
the classical writers. Al-Ghaziili and Yelvuda Halevi were concerned to bring
men to a mystical and nonrational appreciation of religious truths by
making them see the intellectual bankruptcy of the rational theologies then
current. Al-Ghazali’s great treatise that led to the end of the golden age of
Islamic philosophy and science was entitled Autodestruction of the
Philosophers. (This same type of view reappeared in the late Christian
Middle Ages in Nicholas of Cusa’s theory of learned ignorance.)
Renaissance and Reformation. The rediscovery of the classical skeptical
texts during the Renaissance vitally affected the development of modern
thought. The writings of Sextus and Cicero’s De Academica began to
arouse interest again. Present evidence indicates that the Greek text of
Sextus, probably brought to Europe from Constantinople, was known in
manuscript at least as early as 1441, and that various humanistic scholars used
materials from Sextus. In 1562 Henri Estienne (Stephanus) published at Paris a Latin translation of the Pyrroniarum Hypotyposes, and in 1569 Gentian
Hervet published a Latin translation of Adversus Mathematicos at Antwerp. The Greek texts were first printed at Cologne, Paris, and Geneva in 1621. There
is also indication that some of Sextus’ works were translated into English in
the 1590s, but this translation has not been found. A fragment from Sextus was
later published as "The Skepticke," attributed to Sir Walter Raleigh.
A complete English translation of the Hypotyposes appeared in Thomas
Stanley’s History of Philosophy (4 vols., London, 1655-1662). A partial
French translation was done by Samuel Sorbiere in the 1630s, but it was not
published. Another unpublished French translation from the seventeenth century
was discovered in a collection of manuscripts acquired by the University of California at Los Angeles. The first complete French translation, by Claude
Huart, did not appear until 1725.
Religious controversy. At first Renaissance interest in both Academic and
Pyrrhonian views appeared principally in theological discussions. Erasmus, in In
Praise of Folly, after ridiculing various Scholastics, remarked that he preferred
the Academics because they were "the least surly of the
philosophers." Later, in his De Libero Arhitrio (Basel, 1524),
attacking Luther’s view, Erasmus contended that the problem of free will was
too complex for humans to comprehend, and Scripture too difficult to interpret
on these matters. Therefore, he recommended the skeptical attitude of suspension
of judgment, along with acceptance of the church’s view. Luther furiously
attacked this skeptical defense of Catholicism in his De Sen;o Arbitrio (Wittenberg, 1525) and insisted that a Christian cannot be a skeptic; that he must be
certain, not dubious, since salvation is at stake. Erasmus could remain a
genial doubter if he wished, but Luther warned him that Judgment Day was to
follow, and "Spiritus sanctus non est Scepticus."
In
the dispute between Erasmus and Luther a fundamental problem that was to
awaken a vital concern with skepticism was raised, the problem of determining
the criterion of ultimate religious knowledge. At Leipzig, Luther had
challenged the church’s criterion: that of the pope, the councils, and
tradition. At the Diet of Worms he had proposed a subjective, private one
instead, that of the dictates of the Holy Spirit to each man’s own conscience.
The ensuing battle to justify either the church’s or the reformers’ criterion
made this classical skeptical problem a living issue. The recently rediscovered
texts ol Sextus, Cicero, and others played a major role in this battle. A
skeptical crisis developed which modern philosophy would seek to resolve.
Erasmus’ solution, that of suspending judgment and accepting the Catholic view
on faith or tradition, was later developed into what is sometimes called
Christian Pyrrhonism.
The
new skepticism. At the
outset of the sixteenth century Gian Francesco Pico della Mirandola (the
nephew of the famous humanist) and Henricus Cornelius Agrippa von Nettesheim
used the skeptical arguments to attack the Scholastics, the new Renaissance
scientists, the alchemists, the cabalists, and others and, by undermining all
confidence in man’s alleged rational achievements, to lead him to true religion. Renaissance
changes in man’s conception of the cosmos further intensified the emerging
skeptical crisis. Voyages of exploration and new astronomical theories and
discoveries destroyed many of the medies’al beliefs about the nature and
content of the cosmos. Reports of explorers concerning the superior moral
character of savages cast doubt on previously accepted moral theories. The
rediscovery of classical theories made many thinkers dubious about scholastic
methods and conclusions. A wide spectrum of creative theories emanating from Iberia—cabalism, mysticism, and other doctrines— added to the unsettling ferment. Servetus
and Vesalius revolutionized views about anatomy. Paracelsus challenged
accepted medical theories and practices. The revival of interest in Hebrew, in
Jewish views, and in early and deviant Christian theories raised still further
problems. Most crucial of all, almost every accepted theological doctrine was
now questioned, and a wide variety of other possibilities were offered.
In
this atmosphere a series of new skeptical writings appeared. Some plainly and
simply urged, because of the bankruptcy of human reason, acceptance of the wise
conclusion of the ancient skeptics as well as acceptance of traditional
religion. Pedro Valencia’s Academica (Antwerp, 1596) offered a survey of
ancient skepticism, claiming it would make one realize that the Greek
philosophers had not found the truth, and that one should turn away from the
philosophers to God and recognize that Jesus is the only sage.
Hervel. Gentian Hervet, secretary to the Cardinal of Lorraine and a veteran of
the Council of Trent, pointed out in the preface to his Latin translation of
Sextus that the importance of this ancient work was its demonstration that
human reason is incapable of opposing or resisting the arguments that can be
raised against it. God’s revelation is our only source of certainty. Therefore,
he contended, the arguments of Sextus provided a powerful answer to Calvinism.
The Calvinists claimed to have a new theory about God. By showing that all
human claims to knowledge are dubious, Hervet contended that those of Calvin
are dubious as well. When man realized the vanity of all attempts to
comprehend the universe, he would become humble and recognize that Cod can be
known only by faith, not by the reasoning of the reformers. Hervet’s employment
of Pyrrhonism against Calvinism was soon to be shaped into a skeptical machine
of war for use by the Counter Reformation.
Sanches
and Montaigne. The most
philosophical statements of the new skepticism and its relevance to the problems
of the day were offered by Michel de Montaigne and his distant cousin Francisco
Sanches. Sanches (c. 1550-1623), an Iberian refugee from the Inquisition,
taught philosophy and medicine at Toulouse. In his Quod Nihil Scitus, written
in 1576 and published in 1581, he used the classical skeptical arguments to
show that science, in the Aristotelian sense of giving necessary reasons or
causes for the behavior of nature, cannot be attained. He then argued that even
his own notion of science-perfect knowledge of an individual thing—is beyond
human capabilities because of the nature of objects and the nature
of man. The interrelation of objects, their
unlimited number,
and their ever-changing character prevent their being known. The limitations
and variability of man’s senses restrict him to knowledge of appearances, never
of real substances.
Sanches’
first conclusion was the usual fideistic one of the time, that truth can be
gained only by faith. His second conclusion was to play an important role in
later thought: just because nothing can be known in an ultimate sense, we
should not abandon all attempts at knowledge but should try to gain what knowledge
we can, namely, limited, imperfect knowledge of some of those things which we
become acquainted with through observation, experience, and judgment. The
realization that nihil scitur ("nothing is
known") thus can yield some constructive results. This early formulation
of "constructive" or "mitigated" skepticism new to be
developed into an important explication of the new science by Marin Mersenae,
Pierre Gassendi, and the leaders of the Royal Society.
The most
influential version of the new skepticism in setting the problems for modern
philosophy was Montaigne’s. His rambling essay Apologie de Haimond Scbond, written
shortly after he read Sextus and went through his own personal crise
pyrrhonienne, summed up the skeptical currents of the sixteenth century and
showed why all of man’s rational achievements up to that point were seriously
in doubt. Starting from a quibble about the validity of the arguments of the
fifteenth-century Spanish theologian Sebond (Raymond de Sabunde), Montaigne
moved to a general skeptical critique of the possibility of human beings
understanding anything. He kept repeating that only through faith and
revelation can real knowledge be gained. Montaigne used a vast variety of
ancient skeptical arguments, often modernizd by new examples. He stressed
the skeptical difficulties involved in judging the reliability of sense
experience. He pointed out the personal, social, and cultural factors that
influence people’s judgments. And he showed that the criteria employed to
determine standards of judgment are themselves open to question and doubt,
unless Cod gives us some indubitable first principles and makes our faculties
reliable- Unaided by divine grace, all of man’s achievements, even those of the
most recent scientists, become dubious. All we can do, Montaigne asserted, is
follow the Pyrrhonian suspension of judgment, live according to nature and
custom, and accept what God chooses to reveal to us.
The seventeenth century. Montaigne’s skepticism, both as set forth in the Apologie
and in the more didactic presentations of his disciples, Pierre Charron’s De
la Sagesse (Bordeaux, 1601) and Jean-Pierre Camus’ Essay sceptique (Paris,
1603), became most popular in the early seventeenth century, especially among
the avant-garde intellectuals in Paris. The so-called libertins, including
Gabriel Naude, Mazarin’s secretary; Guy Patin, rector of the Sor-bonne medical
school; and Francois de La Mothe Le Vayer, teacher of the dauphin, espoused
Montaigne’s attitude and were often accused of being skeptical even of
fundamental religious tenets. Others, like Francois Veron, used the arguments
of Sextus and Montaigne to challenge the Calvinist claim of gaining true
knowledge from reading Scripture. Counter Reformers, by raising skeptical
episte-mological problems about whether one could determine what book is the Bible, what it actually
says, what it means, and so on, forced Calvinists to seek an indisputable basic
for knowledge as a prelude to defending their theological views.
Gassendi
and Mersenne. Perhaps the most forceful presentation of skepticism in
the early seventeenth century is Pierre Gassendi’s earliest work, Exercitationes
Para-doxicae Adversus Aristoteles (Grenoble.
1624). Gassendi challenged almost every aspect of Aristotle’s view, is well as
many other theories. He applied a battery of ancient and Renaissance skeptical
arguments, including that "No science is possible, least of all in
Aristotle’s sense." In this work Gassendi indicated in embryo what became
his and Marin Mersenne’s constructive solution to the skeptical crisis, the
development of an empirical study of the world of appearances rather than an
attempt to discover the real nature of things.
In the 1620s works challenging the prevalent skeptical tendencies began
to appear. Some authors simply stated that Aristotle would have resolved the
difficulties by-applying his theory of sense perception and knowledge to the
problems raised. Others, like Francois Garasse, decried the irreligious
tendencies they discerned in all this doubting. Still others, like Francis
Bacon, tried to overcome the skeptical difficulties by appealing to new methods
and new instruments that might correct errors and yield firm and unquestionable
results. Herbert of Cher-bury, in De Veritate (1624), offered an
elaborate scheme for overcoming skepticism which combined Aristotelian and
Stoic elements, and ultimately appealed to common notions, or truths known by
all men, as the criteria by which reliable and indubitable judgment would be
possible. Mersenne, in many writings of the 1620s and 1630s, used skeptical
materials (as did Gassendi) to attack the alchemists, the cabalists, and other
Renaissance pseudo scientists, and he tried to mitigate the force of the
skeptical challenge by pointing out how, in fact, worthwhile
"knowledge" is gained. Mersenne granted that the problems raised by
Sextus could not be answered and that, in a fundamental sense, knowledge of the
real nature of things cannot be attained. However, he insisted, information
about appearances and deductions from hypotheses can provide an adequate guide
for living in this world and can be checked by verifying predictions about
future experiences. Gassendi, in his later works, developed this constructive
skepticism as a via media between complete doubt and dogmatism, and
offered his atomic theory as the best hypothetical model for interpreting
experience. Mersenne and Gassendi thus combined skepticism about metaphysical
knowledge of reality with a way of gaining useful information about experience
through a pragmatic scientific method.
Descartes. Rene Descartes, raised in the skeptical atmosphere of
early seventeenth-century France, insisted that it was possible to overcome all
doubt and to find an absolutely certain basis for knowledge. By applying the
skeptical method more thoroughly than the skeptics had, he claimed, an
indubitable truth, as well as an indubitable criterion of true knowledge and a
whole system of truths about reality, could be found. Descartes started by
rejecting all beliefs rendered dubious by the skeptical problems about sense
experience, the possibility that all that we know is part of a dream (a theory’
‘hat appeared in Gicero and Montaigne), and the possibility that there may be a
demon who distorts our judgment (a new skeptical possibility which he
introduced). In the process of trying to doubt everything, Descartes claimed,
one basic indubitable truth—"I think, therefore I am"—is
encountered. The very act of doubting one’s own existence makes one aware of
the truth that one exists. By examining what characteristics make this truth
indubitable, the criterion of true knowledge, that whatever ideas are clearly
and distinctly perceived are true, is discovered. This criterion then enables
one to find true first principles among one’s ideas and to use these principles
to prove that there is a God, that God is not a deceiver, that he guarantees
that whatever we clearly and distinctly perceive really is true, and that there
is an external world. The Cartesian "way of ideas," then, takes
skepticism as its point of departure, uses it to reveal a basis of certitude,
and then further uses it to gain indubitable metaphysical knowledge from our
clear and distinct ideas.
Replies to
Descartes. Descartes’s
dramatic resolution of the skeptical crisis generated a new era of skeptical
argumentation. The skeptics sought to show that Descartes had not really
conquered skepticism, while his dogmatic opponents tried to show that he was
actually a skeptic in spite of himself. To refute Descartes, traditional
skeptical arguments had to be refashioned and redirected. In the objections
to Descartes’s Meditations (Paris, 1641), Gassendi, Mersenne, and others
argued that either fundamental skeptical difficulties remained in the Cartesian
system or that Descartes had not really established anything absolutely
certain. During the rest of the seventeenth century skeptical challenges were
raised about what, if anything, had actually been proved by the cogito, about
whether Descartes’s criterion was of any value, and about whether the
"truths" Descartes enunciated about the mathematical-physical
universe were actually certain or ever true. Gassendi, and later Pierre-Daniel
Huet, charged that cither the cogito stated an uninteresting truism or it was
fraught with problems. Huet’s Censura Philosophae Car-tesiana (Paris, 1689) and his unpublished defense of it raised doubts about each element of the
proposition "I think, therefore I am" until it became "I may
have thought, therefore perhaps I may be." Gassendi, Huet, and others
questioned whether Descartes’s criterion could determine what was true or
false. Could we really tell what was clear and distinct, or could we only tell
that something appeared clear and distinct to us? Would we then need another
criterion to tell when the first actually applied, and so on? Mersenne pointed
out that even with the criterion we could not be sure that what was clear and
distinct to us, and hence true, was really true for God. Hence, in an ultimate
sense, even the most certain Cartesian knowledge might be false. Gassendi, in
what Descartes called "the objection of objections," pointed out
that for all anyone could ascertain, the whole Cartesian system of truths might
be only a subjective vision in somebody’s mind and not a true picture of
reality. Huet argued that since all the fundamental Cartesian data consisted of
ideas, and ideas are not real physical things, the Cartesian world of
ideas, even if clear and distinct, cannot represent something quite different
from itself.
Followers of Descartes. As Cartesianism was attacked from many sides, adherents
modified it in various ways. The radical revision of Nicolas Malebranche,
designed partially to avoid skeptical difficulties involved in connecting the
world of ideas with reality, was immediately attacked by the skeptic Simon
Foucher. The orthodox Cartesian Antoine Arnauld claimed that Malebranchism
could only lead to a most dangerous Pyrrhonism. Foucher, who wished to revive
Academic skepticism, applied various skeptical gambits to Malebranche’s
theory, one of which was to be important in subsequent philosophy. He argued
that the skeptical difficulties which Descartes and Malebranche used to deny
that sense qualities (the so-called secondary qualities—color, sound, heat,
taste, smell) were features of real objects, applied as well to the mathematically
describable primary qualities like extension and motion, which the Cartesians
considered the fundamental properties of things. These mathematical qualities,
as perceived, are as variable and as subjective as the others. If the skeptical
arguments are sufficient to cause doubt about the ontological status of
secondary qualities, Foucher contended, they are also sufficient to lead us to
doubt that primary ones are genuine features of reality.
English skepticism. While the French skeptics were busily challenging the
new dogmatism of Descartes, in England a somewhat different kind of skepticism
was developing. As a result of theological controversies, some Anglican
writers, starting with William Chillingworth, tried to distinguish
unanswerable, hyperbolic, and metaphysical doubts, of the sort raised by
Sextos and Descartes, from reasonable ones that could be dealt with in terms of
probabilities and common sense. They pointed out that absolutely certain
knowledge about the world is unattainable. However, there is information that
can be called knowledge in the sense that it cannot reasonably be doubted.
Bishop John Wilkins and Joseph Glanvill, two early members of the Royal
Society, distinguished between infallibly certain and indubitably certain
knowledge. Infallibly certain knowledge cannot be attained by human beings
because their faculties may be corrupt or defective, and any of the necessary
connections they think they discover in the world may be mere concomitancies
which could be otherwise. However, in ordinary life there are many indubitable
beliefs that no reasonable man questions. In terms of this distinction Wilkins,
Glanvill, and their colleagues built up a theory of empirical science and
jurisprudence for studying nature and deciding human problems within the limits
of "reasonable doubt." Their limited skepticism appears in the
Anglo-American theory’ of legal evidence and in the theory of legal evidence
and in the theory of science of the early Royal Society. They believed that by
applying their probabilistic empirical method to religious questions they could
justify a tolerant, latitudinarian form of Christianity. John Locke to some
extent followed their views in rejecting total skepticism as unreasonable and
in appealing to common-sense standards to answer or avoid traditional skeptical
difficulties.
Other resolutions of skepticism. Other, answers were offered to the skeptics
and to their challenge of some of the basic tenets of the new philosophy.
Hobbes had admitted the force of the problem of finding the criterion forejudging
what was genuinely true, and he insisted that the solution was ultimately
political—the sovereign would have to decide. Pascal in his scientific works
gave one of the fines! expositions of the hypothetical probabilistic nature of
science and mathematics. In his Pensees he stated the case for ultimate
and complete skepticism as strongly as it ever has been done. But, he
contended, no matter how much reason leads us to doubt, "I lay it down as
a fact that there never has been a real complete skeptic. Nature sustains our
feeble reason, and prevents it raving to this extent." (Arnauld, in the Port-Royal
Logic, similarly called the Pyrrhonists a sect of liars, since they could
not believe what they said.) Pascal portrayed man as both a natural and
instinctive believer and "a sink of uncertainty and error." His
solution lay in turning to God, not in any philosophical answer. Spinoza, on
the other hand, with his completely rational vision of the world, could not
regard skepticism as a serious problem. If one had clear and adequate ideas,
there would be no need or excuse for doubting. Doubt was only an indication of
lack of clarity, not of basic philosophical difficulties.
The philosopher who took the skeptics most seriously was Leibniz, a
close friend of Huet and Foucher and a correspondent of Pierre Bayle’s. Many of
Leibniz’ most famous statements of his views are answers to these skeptics.
Leibniz believed that his system of logic, epistemol-ogy, and metaphysics was
impervious to their criticisms. Foucher tried to show him that he failed to
take seriously the skeptical challenge to the very principles of reasoning that
he employed and to the traditional assumptions about the nature of knowledge
that he accepted. Bayle, in the article "Rorarius" in his Dictionnaire
historique et critique, offered the first major critique of Leibniz’
theory of the pre-established harmony, showing it had been no more successful
in resolving skeptical difficulties than had previous metaphysical systems and
was at least as implausible as the others.
Bayle and
the Enlightenment. At the
end of a century of attempts to deal with the skeptical crisis, perhaps the
most incisive of the modern skeptics, Pierre Bayle, summed up the
seventeenth-century intellectual situation in his monumental Dictionnaire
historique et critique (2 vols., Rotterdam, 1697-1702), in which he
opposed "everything that is said and everything that is done."
Bayle’s Dictionnaire is biographical, and most of the important
discussion occurs in long, digressive footnotes to lives of often very insignificant
figures. Bayle was a master dialectician who delighted in offering skeptical
challenges to philosophical and theological theories, ancient or modern, from
Thales to Leibniz, Locke, and Newton. Using all the gambits of the skeptical
tradition, Bayle sought to show that most theories "are big with
contradiction and absurdity" and that man’s efforts to comprehend the
world in rational terms always end in perplexities, bewilderment, and
insoluble difficulties. He thereby developed a most extreme skepticism,
questioning the knowledge claims of theology, metaphysics, mathematics, and the
sciences. In notes B and C to his article "Pyrrho," and in his
clarification of the article in the Appendix, Bayle argued that the new philosophy
cast all in doubt. It had started from the doubts of Sextus Empiricus, and in
spite of Descartes’s efforts and those of his successors, it was ending in a
complete skeptical debacle. Using Foucher’s argument and some ammunition from
Malebranche, Bayle contended that the doubts accepted by modern philosophers
about the real external existence of secondary qualities applied to the primary
ones as well, so that we cannot tell what characteristics the external world
might have, nor even if there is one.
Gassendi
and Huet had challenged whether the Cartesian criterion could ever be
successfully applied. Bayle challenged whether it was even the criterion of
knowledge. He argued for the possibility of a proposition’s being clear and
distinct and yet demonstratively false. (Many theologians and philosophers
tried to refute this challenge by showing that rational discourse would be
destroyed if no standards existed.)
The
point of his skeptical attack, Bayle insisted, was to make men see that
philosophy was an unsatisfactory’ guide and could only lead to doubts. Then,
perhaps, they would abandon reason and turn to faith. Bayle’s presentation of
what this turn to faith involves has none of the fervor of Pascal. It usually
seems to be just a tepid statement of the unintelligibility and amorality of a
faith that is to be accepted blindly. What he himself believed is almost impossible
to determine in the morass of doubts. Bayle also employed his skepticism as a
justification for complete toleration. If all theories about the ultimate
nature of reality are questionable, can there be any basis for persecuting
people for accepting one rather than another? People accept views on the basis
of what their consciences force them to believe. An erring conscience would
have the same effect as a correct one in compelling assent. Since right or true
belief cannot be distinguished from false ones, there is no justification for
persecuting people for their beliefs.
Bayle’s Dictionnaire was the coup) de grace to the seventeenth
century’s attempt to find a new metaphysical basis for certain knowledge. Among
major philosophers, only George Berkeley thought the skeptical crisis could
still be resolved through another metaphysical scheme. By denying the
ontological distinction between ideas and things, and thereby removing the
basis for many of the skeptical arguments, Berkeley thought he could refute the
skeptics and establish the reality of human knowledge. To his chagrin, he was
soon classed as just one more ingenious skeptic, as well as a visionary with a
strange spiritualistic metaphysics. Almost everyone else seemed willing to
accept Bayle’s demolishing of the quest for metaphysical certainty. His
skeptical arguments were soon applied to traditional religion by Voltaire and
others. But in place of Bayle’s doubts or his appeal to faith, they offered a
new way of understanding man’s world—that of Newtonian science—and professed an
inordinate optimism about what man could comprehend and accomplish through
scientific examination and induction. Though Bayle remained the heroic figure
who had launched the Age of Reason by criticizing all the superstitions of past
philosophy and theology, the leaders of the Enlightenment, both in France and in the British Isles, felt that his skepticism was passe and only represented the summit
of human understanding before "God said. Let Newton be, and all was
light." Various simple answers were now offered to skepticism, some by the
Scottish moral theorists and some by overzealous dogmatists like Jean Pierre de
Crousaz, who accused skepticism of being responsible for everything evil,
including even financial crises.
Hume. In the euphoric intellectual atmosphere of the eighteenth century,
David Hume still worried about skepticism. An avid reader of Bayle, Hume seems
to have lived through his own personal skeptical crisis as ho wrote his A Treatise
of Human Nature. Hume sometimes held a most extreme skeptical position,
going at least as far as Bayle in questioning even the knowledge claims of
science, mathematics, and logical reasoning, and sometimes held a limited,
mitigated skepticism allowing for probabilistic standards for evaluating
beliefs about what is beyond immediate experience. When Hume examined the
general nature of all beliefs, he tended toward complete skepticism. When he examined
metaphysics and theology, in contrast with science, he tended toward a
positivistic, limited skepticism. And when he developed his own views about
human nature and conduct, his doubts tended to recede and his positive views
became more pronounced.
Hume had a
Newtonian vision that if the "experimental method of reasoning" were
applied to moral subjects, the character of man’s intellectual endeavors would
be clarified and the limits of human capacities would be made apparent. The
enthusiasm of Hume’s Preface indicates his optimism about constructing "a
science of man." His analysis revealed a skepticism about man’s ability to
gain knowledge about anything beyond the immediately obvious or demonstrable
relationships of his ideas. In the course of the Treatise and the Enquiry
Concerning Human Understanding, Hume showed that no truths about matters of
fact could be established deductively or inductively. Since any conceivable
(imaginable) state of affairs is possible, Hume argued that no genuine
demonstrative evidence could establish that something must be, and could not
be otherwise. Inductive reasoning, Hume pointed out, is inconclusive, since its
evidential value rests upon the assumption that nature is uniform, that the
future will resemble the past. This assumption cannot itself be justified. Our
information about the world beyond what is immediately perceived, except for
"forced" beliefs, is the result of causal reasoning from a present
impression to its supposed cause or effect. In analyzing such "reasoning,"
Hume showed that we are unable to discover any necessary connections among
experienced events or any justifiable basis for applying data about the
constant conjunctions of past events to future ones. When we examine why we
believe that certain relationships exist between matters of fact, we see that
customs or habits, rather than rational evidence, lead us to the views we hold.
The quest for a justifiable basis for belief always reveals how unjustified
are our beliefs about matters not immediately experienced. In Book I, Part IV
of the Treatise, the last chapter of the Enquiry, and the Dialogues
Concerning Natural Religion Hume undermined the reliability of rational and
empirical arguments in philosophy and theology, and raised doubts concerning
the merits of logical argumentation about the existence of an external world,
of the self, and of God.
When we examine what we believe and what leads us to believe it, we find
that "Philosophy would render us entirely Pyrrhonian, were not Nature too
strong for it." The skeptical problems notwithstanding, we are naturally
constrained to believe all sorts of things. Under normal conditions we find
that we are led by nature to believe that the future course of events will
resemble the past course, and on this we base our so-called
"reasonable" or "scientific" views and expectations about
the world. But nature does not refute complete skepticism. It only prevents us
from believing in, or accepting, the doubts that result from skeptical
reasonings.
Hume
showed that man was caught between a total Pyrrhonism that he could not refute
and a natural compulsion to believe in the future course of events, the
reality of an external world, the existence of some kind of personal identity,
and possibly in some kind of intelligent force in the world. These metaphysical
and theological views were indefensible but unavoidable. The Hurnean skeptic
could only accept the situation and explore, the reasons for doubting when he
felt inclined to, at other times accepting what he found he had to believe. In
a sense, Hume’s skepticism was a more consistent and forceful statement of the.
original Pyrrhonian view. Though less detailed and thorough than Bayle’s dialectical
demolishment of a wide variety of knowledge claims, Hume’s version centered the
skeptical attack on the issues that were to dominate subsequent philosophy—the
problems of induction, causality, external existence, the nature of the
self, and the proofs of the existence of God. And Hume showed what was actually
involved in the Pyrrhonian statement that the skeptic accepts beliefs by habit
and custom, and according to nature. The skeptic could not suspend judgment on
all questions without going mad, since "Nature, by an absolute and
uncontrolable necessity has determin’d us to judge as well as to breathe and
feel" (Treatise of Human Nature, Book I, Part 4, Sec. 1). More than
any of his predecessors, Hume explored the nature of beliefs and the factors
that induce people to accept them.
Reid and the common-sense school. In an era when most of his philosophical
contemporaries were overly optimistic about human capabilities to comprehend
the world, Hume’s skepticism was largely ignored, while his psychological,
historical, political, and antireligious works were taken as a great
contribution to the Age of Reason. One of the first to appreciate Hume’s
skeptical arguments was Thomas Reid, who studied Hume’s writings for 25 years
before publishing his answer. Inquiry into the Human Mind on the Principles
of Common Sense (Edinburgh, 1764). Reid discerned that both Berkeley and
Hume had shown that the basic principles of modern philosophy led
systematically to total skepticism about man’s ability to attain any certainty
or even probability about the world. The answer to this development, Reid
contended, was not to ignore or scoff at the arguments of Berkeley and Hume but
to reconsider the assumptions on which modem philosophy is based. When the
conclusions of philosophy run counter to common sense, there must be something
wrong with philosophy. Since nobody could believe and act by complete
skepticism, the fact that this skepticism was the consistent issue of
the Cartesian and Lockean way of ideas only showed the need to start anew. Reid
offered his common-sense realism as a way of avoiding Hume’s skepticism by
employing as basic principles the beliefs we arc psychologically unable to
doubt.
Hume was unimpressed by Reid’s argument Reid, he believed, had seen the
problem but actually had only offered Hume’s own solution, that nature does not
allow us to live as if all were in doubt, even though we are unable to resolve
all doubts theoretically. The Scottish common-sense school of Oswald, Beattie, Stewart, Brown, and others kept reiterating its claim to having refuted
Hume’s skepticism by appealing to natural belief, while at the same time
conceding that Hume’s fundamental arguments could not be answered. Thomas
Brown, an early nineteenth-century’ disciple of Reid, admitted that Reid and
Hume differed more in words than in opinions, saying, "’Yes. Reid bawled
out, ‘we must believe in an outward world’; but added in a whisper, ‘we can
give no reason for our belief.’ Hume cries out, ‘we can give no reason for such
a notion’; and whispers, ‘I own we cannot get rid of it" (Sir James
Mackintosh, Dissertation on the Progress of Ethical Philosophy, 2d ed.,
Edinburgh, 1837, p. 346).
The German Enlightenment and Kant. The Scottish school was perhaps the first to
make Hume’s version of modem skepticism the central view to be combated if
philosophy was to make coherent sense of man’s universe. The more fundamental
attempt, for subsequent philosophy, to deal with Hume’s skepticism was
developed in Germany in the second half of the eighteenth century and
culminated in Kant’s critical philosophy. Such leaders of the Prussian Academy as Jean Henry Samuel Formey. Johann Bernhard Merian, and Johann Georg Sulzer
had long been arguing against Pyrrhonism. They were among the first to read,
translate (into French and German), and criticize Hume’s writings. They saw in
the skeptical tradition up to Bayle and Huet, and in Hume’s version of it, a
major challenge to all man’s intellectual achievements Although their answers
to skepticism were hardly equal to the threat they saw in it, these writers
helped revive intercst in and concern with skepticism in an age that thought it
had solved, or was about to solve, all problems Others in Germany contributed
to an awareness of the force of skepticism: Johmn Ghristoff Eschenbafch by his
edition of the arguments of Sextus, Berkeley, and Arthur Collier, Berkeley’s
contemporary, against knowledge of an external corporeal world; Ernst Plainer
by his skeptical aphorisms and his German edition of Hume’s Dialogues on
Natural Religion (1781); hosts of German professors by dissertations against skepticism; and the translators of the Scottish
critics of Hume.
The culmination of this German concern with skepticism occurred when
Kant was awakened from his dogmatic slumbers by reading Hume and his opponents-
Kant save that Hume had fundamentally challenged the
Enlightenment hope that all skeptical disputes could be settled by what Locke
had called "the physiology of the understanding." and that the
question "How is knowledge possible? had to be re-examined. Kant’s
solution can be considered as an attempt to establish a middle ground
inoorporating complete skepticism about metaphysical knowledge and a conviction
that universal and necessarily certain knowledge existed about the conditions of all possible
experience. He assumed that knowledge is possible, and hence that total
skepticism is false. The problem was then to explain how this universal and
necessary information could be attained, in the face of Hume’s arguments. In
the view that knowledge begins with experience, but does not come from it, Kant
believed he had found a revolutionary new answer to the skeptical crisis. Space
and time are the necessary forms of all possible experience, and the categories
and the logical forms of judgment are the conditions of all knowledge about
experience. Mathematical knowledge is possible because it is not derived by
induction from experience but is the way the world must be experienced, A
science of nature is possible because all experience must be ordered and
organized according to certain categories.
By
transcendental analysis we can uncover the universal and necessary conditions
imposed on all experience and judgment. But these conditions provide no means
for gaining knowledge either about the contents of experience (as opposed to
its form) or about what transcends experience, a supposed real world, a self,
and God. The contents of experience can be learned only empirically and
inductively, and such information is only probable. Metaphysical knowledge
cannot be attained, since there is no way of telling if the conditions of
experience apply beyond the limits of all possible experience, and no way of
telling what to apply them to.
Skeptical
rejoinders to Kant. Kant
and his disciple Karl Friedrich Staudlin (who wrote the first systematic
history of skepticism, from Pyrrho to Kant) regarded Kant’s critical philosophy
as the finale of man’s long struggle with skepticism. Kant’s contemporaries
and successors, however, saw his effort as beginning a new phase in skeptical
thought and providing a new road to Pyrrhonism. From three different sides Kant
was attacked by skeptical critics, each employing a portion of the earlier
skeptical tradition as a way of showing that Kant had failed to resolve the
skeptical crisis. G. E. Schulze (also known as Aenesidemus-Schulze, after the
title of his major work of 1792) argued that Kant had not succeeded in
establishing any genuine truths about objective reality, since as Kant himself
had shown, there is no way of extending information about the conditions of
thought to real objects, or things-in-themselves. But without any such
extension, the objective validity of our judgments cannot be determined. At
best, all that can be established is the subjective necessity of certain of our
views, which is essentially what Hume had shown. So Schulze, by insisting on
the inability of the Kantian analysis to move from subjective data about what
people have to believe to any objective claims about reality, contended that
Kant had not advanced beyond Hume’s skepticism, and that this failure of the
Kantian revolution actually constituted a vindication of Hume’s views.
Salomon Maimon challenged Kant’s theory from within and developed a view
which he called "rational skepticism." In contrast with Hume, Maimon
agreed with Kant that there were rational a priori concepts, such as those
involved in mathematics. In opposition to Kant, Maimon held that the
applicability of transcendental concepts to experience w-as itself something
based on inductions from experience. Since such inductions could only be
probable.no universal and necessary knowledge about experience could be gained.
Kant had assumed that such knowledge existed, and examined how this was
possible. Maimon asked whether it was, and showed that the evidence was
always experiential. Inductively it might become more and more probable that a
priori concepts applied to experience, but, because of Hume’s critique of
induction, we must remain skeptical on this score. Maimon ruled out metaphysical
knowledge as unattainable, on both Humean and Kantian grounds.
Thus
Maimon developed a mitigated Kantianism (to some extent like that of the
Neo-Kantian movement a century later) in which the reality of a priori forms
of thought is granted but in which the relation of these forms to matters of
fact is always in question. Knowledge (that is, propositions that are
universal and necessary, rather than ones that are just psychologically
indubitable) is possible in mathematics but not in sciences dealing with the
world. Unlike the logical positivists, who were to claim that mathematics was
true because it consisted only of vacuous logical tautologies, Maimon contended
that mathematics was true because it was about creations of our mind. Its
objective relevance was always problematical. This turn to human creativity as
the basis of truth was soon to be expanded by Fichte as a new road to
knowledge of reality and a means of transcending skepticism.
Maimon’s partial skepticism exposed some of the fundamental limitations
of Kant’s critical philosophy as a solution to the skeptical crisis. Another
skeptical critique was offered by the religious thinker Johann Georg Hamann,
who accepted Hume’s and Kant’s arguments as evidence that knowledge of reality
cannot be gained by rational means but only by faith. Hamann exploited the
skeptical thought of these philosophies to press for a complete anti-rational
fideism. He used Hume’s analyses of miracles and of the evidence for religious
knowledge to try to convince Kant of the futility of the search for truth by
rational means. During the height of nineteenth-century positivism,
materialism, and idealism, Hamann’s type of fideism was revitalized by
Kierkegaard and Lamennais, who used it as a critique of French liberal,
empirical, and Enlightenment views and as a new defense of orthodoxy and
political conservatism. Kierkegaard brilliantly combined themes from Sextos,
Hume, and Hamann to attack the rationalism of the Hegelians, to develop 3
thoroughgoing skepticism about rational achievements, and to show the need for
faith in opposition to reason. Fideism has become a major element in
twentieth-century neo-orthodox and existentialist theology, which tries to show
that the traditional skeptical problems still prevent us from finding an
ultimate basis for our beliefs except by faith.
Idealism. In the mainstream of philosophy after Kant, although skepticism
continues to play a vital role, few philosophers have been willing to call themselves
skeptics. The German metaphysicians, from Fichte and Hegel onward, sought to
escape from the skeptical impasse produced by Hume and Kant and to reach
knowledge of reality through the creative process and the recognition of
historical development They attempted to portray skepticism as a stage in the
awareness and understanding of the process of events. For Fichte skepticism
made one recognize the need for commitment to a fundamental outlook
about the world. The commitment to see the world in terms of creative thought
processes led to a revelation of the structure of the universe as an aspect of
the Absolute Ego.
For Hegel skepticism was the nadir of philosophy, actually its
antithesis. According to Hegel, human knowledge is a historically developing
process. At each stage of the process both our knowledge and the world itself
arc limited and contain contradictions, which are overcome at the next stage.
Only the final, Absolute stage, when no further contradictions can be
developed, permits genuine knowledge that is not partly true and partly false.
Then, presumably, skepticism is no longer possible. The English Hegelian F. H.
Bradley, in his Appearance and Reality (London, 1893), used the
traditional skeptical arguments to show that the world was unintelligible in
terms of empirical or materialistic categories, and hence that one had to go
beyond the world appearance to find true knowledge.
Recent
assimilation of skepticism. The empirical and positivistic critique of
speculative metaphysics, launched in the late nineteenth and early twentieth
centuries by Ernst Mach, Bertrand Russell, Rudolf Carnap, and others, included
a skepticism about the possibility of any metaphysical knowledge (amounting in
some formulations almost to the Academic skeptical view that no knowledge
beyond appearances is possible). Logical positivism and the later linguistic
philosophy have tried to obviate the skeptical problems by restricting the use
of the term "knowledge" to logically true tautologies, empirically
verifiable facts, or ordinary common-sense beliefs and assertions. Similarly,
pragmatists from William James onward have sought to eliminate skeptical difficulties
by limiting the meaning of "true knowledge" to hypotheses that are
pragmatically confirmed or verified. In such views, metaphysical assertions are
no longer ranked as false or dubious but as nonsense, or non-assertions. They
can be evaluated as poetic utterances, or appreciated for their emotive
qualities, but they have no truth value.
Many
other major views of the. last hundred years, whether intentionally or not,
have included or taken for granted various aspects of traditional skepticism.
Empiricists, from John Stuart Mill onward, have not claimed to have found any
means of attaining certain knowledge beyond the world of experience or
appearance, except in terms of logical and/or mathematical tautologies. And the
information about the world of experience, they have granted, is only probable.
The sciences have systematized our understanding of these data but have not
thereby shown that they arc necessarily true. On the contrary, the
probabilistic nature of science has been used by Russell and others as a
constant warning against various dogmatic views. Russell, in his discussions of
induction, has repeatedly stressed the logical force of the arguments offered
to develop an extreme or complete skepticism.
James, Sigmund Freud, Karl Mannheim, and Charles Beard, while they have
provided much insight into why we hold the views we do, have at the same time
spawned newer forms of relativistic skepticism. By revealing the economic,
social, and psychological factors that have led us to our beliefs, they have
made it difficult, if not impossible, for us to consider the truth of what we
believe apart from how or why we believe it. Truths, in the views of these
writers, become relative to the person holding them and to the conditions under
which they are held, rather than absolute assertions about the nature of
things.
In
a world in which most thinkers are covertly skeptical about the possibility of
attaining knowledge concerning reality, there have been few overt skeptics
recently. Since for many the impasse reached by Humean and Kantian thought is
taken as the end of the quest for certain knowledge of reality, the skeptical
problems seem out-of-date and irrelevant. When they are transferred from their
original locus into questions about experience or common-sense belief, they
appear odd and sometimes easily answerable, although these are hardly the same
problems. The continuing appearance of refutations of skepticism by
contemporary philosophers indicates, perhaps, that to some extent they are
still haunted by the problems that no longer seem soluble.
Recent
skeptics. Besides those contemporary fideists who employ skepticism as a road
to religious faith, one might include as overt skeptics among twentieth-century
thinkers such diverse figures as Fritz Mauthner, George Santayana, and Albert
Camus, and as quasi skeptics figures like Hans Vaihinger, Alain, and possibly Karl
Popper. Mauthner, in the early part of the century, developed a type of
skepticism from his work on the analysis of language. Any language, he
contended, is both social and individual, and shows only what linguistic
conventions are used at given times and what features of experience they name
in various ways. Each language expresses a Weltanschauung, and what is
considered as true in a language is always relative to this outlook. When one
attempts to ascertain what is true, one is thrown back on data about linguistic
conventions and cannot proceed to any independent evaluation of the actual
correspondence of assertions to objective states oi affairs.
Mauthner’s
critique of language led him into complete skepticism about the possibility of
genuine knowledge. Even his critique, he realized, was an attempt "to say
the unsayable," and thus silent mystic contemplation was all that was
really possible. In the light of his studies of atheism and religion, Mauthner
called himself a "godless" mystic; "godless" because,
according to his critique of language, "God" was as unwarranted a
substantive name as any other.
A kind of naturalistic skepticism was offered by George Santayana,
expecially in his Scepticism and Animal Faith (New York, 1923).
Santayana insisted that "nothing given exists as it is given," and
that all our beliefs about what is given are open to question. He contended
that he was carrying skepticism further than Hume, had, in that he questioned
both Hume’s description of what is given and his psychological interpretations
of experience.
When the full force of complete skepticism is realized, Santayana
claimed, one can appreciate what is in fact absolutely indubitable, the
immediately experienced or intuited qualities that Santayana called
"essences." The interpretation of these essences leads to various
questionable metaphysical systems. A thoroughgoing skepticism makes one
realize the unjustifiable assumptions involved in interpreting the realm of
essences, and also that we do
interpret them and thereby construct meaningful
pictures of the world- Santayana called the process of interpretation
"animal faith," which is consistent with complete skepticism and
involves following natural and social tendencies and inclinations.
I have
imitated the Creek sceptics in calling doubtful everything that, in spite of
common sense, anyone can possibly doubt. But since life and even discussion
forces me to break away from a complete scepticism, I have determined not to do
so surreptitiously nor at random, ignominiously taking cover now behind one
prejudice and now behind another. Instead, I have frankly taken nature by the
hand, accepting as ft rule in my farthest speculations the animal faith I live
by from day to day. [Scepticism and Animal Faith, 1955, p. 308)
This animal faith is
guided by biological events, which bring one to beliefs about reason,
experience, and art, all of which may be illusory but which lead to various
"realms of being" that can be studied, appreciated, and lived in.
Another form of twentieth-century skepticism is that of such existentialist
thinkers as Albert Camus. Camus built on the fideistic skepticism of
Kierkegaard and Leon Shes-tov and the skepticism regarding religion and
objective values of Nietzsche. In his Myth of Sisyphus he portrays man
as trying to measure the nature and meaning of an essentially absurd universe
by means of questionable rational and scientific criteria. Camus regards the
skeptical arguments used by Kierkegaard and Shestov as showing the
contradictory nature of human rational attempts to understand the world as
decisive, but he rejects their fideistic solution: overcoming the skeptical
crisis by "a leap into faith." Instead, he accepts Nietzsche’s
picture of the ultimate meaninglessness of the world because "God is
dead." For Camus, the basic absurdity of the human situation, of man
constantly seeking for understanding and meaning in an unintelligible and
meaningless world, must be recognized and accepted. In this situation knowledge
in the traditional sense is unattainable, and no justifiable, or even
plausible, modus vivendi between man’s desires for understanding and
worthwhile goals and the absurd conditions of his existence can be found. The
mythological Sisyphus, eternally pushing a huge rock uphill, only to have it
fall to the bottom again, typifies the human situation. Sisyphus "knows
the whole extent of his wretched condition." He does not expect to find
truth, nor does he expect to end his struggle. He finds no ultimate point or
value in his-situation, but he perseveres with a "silent joy,"
realizing that his struggle has meaning only for him, in terms of his human
condition, and not in any objective frame of reference. The struggle is neither
sterile nor futile for him, though it is meaningless in terms of understanding
or possible achievement.
This type of skepticism, now quite popular, is allied with a kind of
futilitarianism, reflecting the feeling that the optimism of the Enlightenment
and the nineteenth century are illusions. The spiritual collapse of hopes for
progress, peace, and human happiness in the course of the catastrophes of the
twentieth century has led many intellectuals to a fundamental skepticism about
man’s capacity to know and understand his world, and about the merits of the
ideals he has been striving for. This collapse, coupled with a strong skeptical
current running from Bayle, Hume, and Voltaire to Bertrand Russell and others
about the value of the religious and moral traditions of the Western world, has
turned many philosophers away from any serious quest for genuine knowledge
about the nature of reality and has led to the denial of grandiose knowledge
claims and any metaphysical or theological system. The turn toward the
intensive examination of ordinary belie! and language, and of man’s personal
involvement in his allegedly absurd, meaningless situation, is in many ways
like the intellectual atmosphere in which skepticism thrived both in Hellenistic
times and in the late Renaissance. Well-structured’ worlds had collapsed, and
with the collapse of all the frames ol reference no goals any longer seemed
obvious or certain. In those periods, as today, the questioning of basic
assumptions deepened the disillusionment with traditional Weltanschauungen and
led to a quest lor new bases of certainty, knowledge, and values.
THE VALUE OF SKEPTICISM IN PHILOSOPHY
Skepticism has been continually attacked and
"refuted" in the history of philosophy and has only occasionally been
set forth as a serious view. Opponents have argued from Greek times to the
present that skepticism is untenable and that it flics in the face of common
sense and ordinary beliefs. As Hume admitted, one of the characteristics of
skeptical argumentation is that "it admits of no answer, and produces no
conviction."
The
skeptics from Sextus Empiricus to Montaigne, Bayle, Hume, and Santayana have
pointed out that the strength of skepticism lies not in whether it is tenable
as a position but in the force of its arguments against the claims of dogmatic
philosophers. To avoid leaving his opponents the opportunity to challenge the
consistency of skepticism, Sextus carefully avoided stating the view as
anything other than a chronicle of his personal feelings at given moments.
Montaigne indicated that the Pyrrhonians needed a nonassertive language to
state their case, since as soon as they asserted anything, opponents could
claim that they had violated their own views. Bayle and Hume pointed out that
skepticism, if stated and argued for consistently, would be self-refuting but
that this sell-refutation would not take place until skepticism and the
opposing dogmatic views had all been undermined.
However, skepticism has not functioned in philosophy as merely one more
position alongside idealism, materialism, and realism. Instead, it has been
like an anonymous letter received by a dogmatic philosopher who does hold a
position. The letter raises fundamental problems for the recipient by
questioning whether he had adequate grounds for his assertions and assumptions
or whether his system is free from contradictions or absurdities. The recipient
may try’ to fend off the attack by challenging whether any philosopher could
write the letter without opening himself to similar attacks. By imputing an
author, the dogmatist may show the problem involved in consistently stating
skepticism, but he does not thereby reply to the arguments in the letter.
Skeptical arguments are usually parasitical, in that
•60 Skepticism
they assume
the premises of the dogmatist and show problems that ensue, on the standards
of reasoning of the dogmatist.
For the
dogmatist, the skeptical arguments, regardless of whose they are, pose basic
difficulties; and if he sees their relevance to his own views, it is he who
must deal with them if he wants to be satisfied that his system is tenable.
Sextus set forth his arguments primarily in terms of Stoic and Epicurean views;
Montaigne, both in terms of these and of scholastic and Platonic ones;
Gassendi, in terms of Carthesian
escolastic and Renaissance
naturalistic ones; Bayle, in terms of the
system current in his
day—scholastic, Cartesian, Leibnizian, Lockean; and Hume, mainly
in terms of Lockean and Cartesian ones. The upholders of these systems then had
the problem of refuting these arguments within their systems, regardless of
who in fact posed the problems and whether he believed what he appeared to be
saying.
The
historical skeptics did not say that they personally regarded everything as
doubtful. They distinguished believing various matters from having sufficient
reasons for believing them. Regardless of the legends about Pyrrho, the
skeptical authors seem to have followed Huet’s view that it is one thing to
philosophize and another to live, and that many propositions may be
philosophically dubious but acceptable or even indubitable as living options.
The problem posed by skeptical probing was not what do, or what must, people
believe but, rather, what evidence is there for beliefs, and is this evidence
adequate?
From
Creek times onward, skepticism has functioned as a gadfly to dogmatic
philosophy and as a challenge to keep it honest. The skeptical critique has
thrived on the desire to find a coherent and consistent account of our
knowledge and beliefs about the world. Had there never been disillusionment about what was accepted as
true, skepticism would probably not have arisen. Nevertheless, skepticism has
led to continual re-examination of philosophical claims and to new dogmatic
systems trying to avoid difficulties in others. This in turn has led to new
skeptical attacks and ingenious new criticisms or new versions of criticism.
Thus skepticism has been a major dynamic force in intellectual history. And
even if many philosophers are now willing to accept Hume’s friend Thomas
Blacklock’s observation that "the wise in every age conclude, what
I’yrrho taught and Hume renewed, that dogmatists are fools," human foil)’
keeps the quest for knowledge of the ultimate nature of reality going and
skeptics keep challenging the latest claims to such knowledge. Without skepticism,
we probably could not distinguish enthusiasm, prejudice, or superstition from
serious or meaningful beliefs. As Shaftesbury said, after living with Bayle
for a while, any views he had that could survive the continuous skeptical
onslaught, he regarded as being as valuable as the purest gold. Each age is
able to assess the views which are valuable to it only if they are subjected to
the same challenge.
(See
also Appearance and reality; Certainty;
Doubt; Ethical relativism; Fideism; Illusions; induction; irrationausm;
nihilism; other minds; Paradigm-case argument; and Solipsism. See Skepti-
cism in Index
for articles on individual skeptics and on philosophers especially concerned
with rebutting skeptical arguments.)
Bibliography
The following works deal with the history and nature of skepticism. In
addition, see bibliographies to articles on specific skeptical thinkers.
Allen,
Don Cameron, Doubt’s Boundless Sea: Skepticism and Faith in the Renaissance.
Baltimore, 196-1.
Atlas, Samuel. From Critical to Speculative Idealism: The Philosophy of Salomon
Maimon. The Hague, 1964.
Bartholniess, Christian,
Huet. cheque d’Avranches, ou le scepti-isme theologque. Paris, 1850.
Bcvan, Edwyn, Stoics and Skeptics. New York, 1959.
Boas,
Georg, Dominant Themes of Modern Philosophy. New
York, 1957.
Bredvold,
Louis 1., The Intellectual Themes
of Modern Philosophy. New
Arbor, Mich., 1931.
Brochard, Victor, Les Scepliques grecs. Paris, 1887.
Busson, Henri, Le Rationalisme dans la litterature francaise de la Renaissance. Paris,
1957.
Dambska,
Izydora, Sccptycyzm Froncuski XVI i XVII Wicku. Torun, Poland, 1958.
Coedeckemeyer,
Albert, Die Geschichte des griechischen Skep-tiziismus. Leipzig, 1905.
Gregory,
Tullio, Scetticismo ed empirismo: Studio su Cassendi. Bad, 1961.
Hallie,
Philip P., ed., Scepticism, Man, and God. Selections From the Major Writings
of Sextus Empiricus. Middletown, Conn.,
1964. Edited, with introduction, notes, and bibliography by Philip P. Hallie;
translated by Sanford C. Etheridge.
Maccoll,
Norman, The Greek Sceptics From Pyrrho to Sextus. London and Cambridge. 1869.
Mcnendez
Pelayo, Marcellino. Obras completas. Vol. XLIII, Ensayos de critica
filosófica. Santander, 1948. Ch. 2, ‘"De los origenrs del criticismo y del escepticismo
y especialmente de los precursores cspaiioles de Kant," pp. 117-216.
Owen, John, Evening With the Skeptics. London, 1881.
Owen,
John, The Skeptics of the French Renaissance. London and New York, 1893.
Patrick,
Mary Mills, The Gieek Sceptics. New York and London, 1929.
Popkin.
Richard H„ "David Hume: His P>rrhonism and His Critique of
Pvrrhonism." Philosophical Quarterly, Vol. 1 (1950-19511,385-407.
Popkin, Richard H., "Berkeley and Pyrrhonism." Review of
Metaphysics, Vol. 5 (1951-1952). 223-246.
Popkin,
Richard H., "David Hume and the Pyrrhnnian Controversy." Review
of Metaphysics, Vol. 6 (1952-1953). 65-81.
Popkin.
Richard H., ‘The Sceptical Crisis and the Rise of Modern Philosophv."
fifties of Metaphysics, Vol. 7 (1953-1954;. 132-151, 307-323, 499-510.
Popkin,
Richard H.. "The Skeptical Precursors of David Hume." Philosophy
and Phenomenological Research, Vol. 16 (1955J.61-71.
Popkin,
Richard H., The History of Scepticism From Erasmus to Descartes. Asscn.
Netherlands, I960; New York, 1964. Contains lengthy bibliography on skepticism
from 1500 to 1650.
Popkin,
Richard H., "Scepticism and the Counter-reformation in France." Archie fur Reformatiomgeschichte, Vol. 51 (1960), 58-88.
Popkin.
Richard H.. "Scepticism in the Enlightenment,"’in T. Bcstermann, ed.,
Studies on Voltaire and the 18th Century, Vol XXVI. Geneva, 1963. Pp.
1321-1345.
Popkin,
Richard H., ‘Traditionalism, Modernism and Scepticism of Rene Rapin." Filosofia,
Vol. 15 (1964), 751-764.
Popkin,
Richard H., ‘The High Road to Pyrrhonism." American Philosophical
Quarterly, Vol. 2 (1965). 1-15.
Richter,
Raoul, Der Skeptizimus in der Philosophic, 2 vols. Leipzig, 1904-1908. A
history’and examination of skepticism from ancient times to the end of the
nineteenth century.
Robin,
Leon, Pyrrhon et le
scepticisme grec. Paris, 1944.
Russcel. Bertrand, Sceptical Essays. New York, 1928.
Saisset,
Emile, Le Scepticisme: Aenesidcmc, Pascal, Kant. Paris, 1865.
Sanlayana,
George, Scepticism and Animal Faith. New York, 1923; reprinted New York, 1955.
Staudlin, Karl F, Ceschichte und Geist des Skepticismus, 2 vols. Leipzig, 1794.
Tafel, J. F. I., Ceschichte und Kritik des Skepticismus und
Irrationalismus. Tubingen, 1834.
Villey, Pierre, Les Sources et l’evolution des essais de Montaigne. Paris, 1908.
Zeller, Eduard, The Stoics, Epicureans, and Sceptics, translated
by O. J. Reichel, rev. cd. London, 1880.
RICHARD H. POPKIN
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