- For a general discussion of skepticism, see Skepticism.
Philosophical skepticism (from Greek σκέψις, skepsis meaning "enquiry"; UK spelling scepticism) is both a philosophical school of thought and a method that crosses disciplines and cultures. Many skeptics critically examine the meaning systems of their times, and this examination often results in a position of ambiguity or doubt. This skepticism can range from disbelief in contemporary philosophical solutions, to agnosticism, to rejecting the reality of the external world. One kind of scientific skepticism refers to the critical analysis of claims lacking empirical evidence. We are all skeptical of some things, especially since doubt and opposition are not always clearly distinguished. Philosophical skepticism, however, is an old movement with many variations, and contrasts with the view that at least one thing is certain, but if by being certain we mean absolute or unconditional certainty, then it is doubtful if it is rational to claim to be certain about anything. Indeed, for Hellenistic philosophers claiming that at least one thing is certain makes one a dogmatist.
Philosophical skepticism is distinguished from methodological skepticism in that philosophical skepticism is an approach that denies the possibility of certainty in knowledge, whereas methodological skepticism is an approach that subjects all knowledge claims to scrutiny with the goal of sorting out true from false claims.
Ancient Western Skepticism
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The Western tradition of systematic skepticism goes back at least as far as Pyrrho of Elis (b. circa 360 BCE). He was troubled by the disputes that could be found within all philosophical schools of his day. According to a later account of his life, he became overwhelmed by his inability to determine rationally which school was correct. Upon admitting this to himself, he finally achieved the inner peace that he had been seeking.
From a Stoic point of view, Pyrrho found peace by admitting to ignorance and seeming to abandon the criterion by which knowledge is gained. Pyrrho's ignorance was not the ignorance of children or farm animals: it was a knowledgeable ignorance, arrived at through the application of logical reasoning and exposition of its inadequacy. The school of thought developed primarily in opposition to what it saw as the dogmatism, or ultimately unfounded assertions of the Stoics; Pyrrhonists made distinctions between "being" and "appearing" and between the identity and the sensing of a phenomenon.
Pyrrho and his school were not actually "skeptics" in the later sense of the word. They had the goal of αταραξια (ataraxia - peace of mind), and pitted one dogmatic philosophy against the next to undermine belief in the whole philosophic enterprise. The idea was to produce in the student a state of aversion towards what the Pyrrhonists considered arbitrary and inconsequential babble. Since no one can observe or otherwise experience causation, external world (its "externality"), ultimate purpose of the universe or life, justice, divinity, soul, etc., they declared no need to believe in such things. The Pyrrhonists pointed out that, despite claims that such notions were necessary, some people "ignorant" of them get by just fine before learning about them. They further noted that science does not require belief and that faith in intelligible realities is different from pragmatic convention for the sake of experiment. For each intuitive notion (e.g. the existence of an external world), the Pyrrhonists cited a contrary opinion to negate it. They added that consensus indicates neither truth nor even probability. For example, the earth is round, and it would remain so even if everyone believed it were flat. Unless, of course, it is flat, and we all simply believe it is round.
The goal of this critique, which Pyrrho's followers realized would ultimately subvert even their own method, was to cultivate a distrust of all grand talk. They expected philosophy to collapse into itself. How far in this direction the Pyrrhonean commitment extended is a matter of debate. The Pyrrhonists confessed a belief in appearances, e.g. in hot and cold, grief and joy. It is impossible to deny, they admitted, that one seems to be in pain or seems to touch a piece of wood. Their world, thus, was completely phenomenological. An accomplished Pyrrhonist could, ideally, live as well as a dogmatist but with the added benefit of not worrying about truth and falsity, right and wrong, God's will, and so forth.
Later thinkers took up Pyrrho's approach and extended it into modern skepticism. In the process, a split appeared within the movement, never too large or well liked among the literati to begin with. In the Academic skepticism of the New or Middle Academy, Arcesilaus (c. 315-241 BCE) and Carneades (c. 213-129 BCE) argued from Stoic premises that the Stoics were actually committed to denying the possibility of knowledge, but seemed to maintain nothing themselves, but Clitomachus, a student of Carneades, interpreted his teacher's philosophy as suggesting an early probabilistic account of knowledge. The Roman politician and philosopher, Cicero, also seems to have been a supporter of the probabilistic position attributed to the Middle Academy, even if the return to a more dogmatic orientation of that school was already beginning to take place.
1. Some things give animals pleasure which give other animals pain. What is useful to one animal is harmful to another.
2. Each human has a different assortment of preferences, abilities and interests.
3. Each sense gives a different impression of the same object.
4. There is no reason to think we are sane while others are insane. It could be the other way around.
5. Cultures disagree regarding beauty, truth, goodness, religion, life and justice.
6. There is no consistency in perception. (His examples are that the color purple will show different tints depending on the lighting, we look different between noon and sunset and a very heavy rock on land is lighter when in water)
7. The senses can be shown to be deceptive. (From distance, the square tower looks round and the sun looks small)
8. Things that strengthen in moderation will weaken when taken in excess, like wine and food.
9. When a thing is rare, it surprises people. When a thing is common, it does not surprise people.
10. Inter-relations among things are of course relative, and by themselves are unknowable. (i.e. To know 'father' you must know 'son,' but to know 'son' you must know 'father.' Neither can be known by itself)
In the centuries to come, the words Academician and Pyrrhonist would often be used to mean generally skeptic, often ignoring historical changes and distinctions between denial of knowledge and avoidance of belief, between degree of belief and absolute belief, and between possibility and probability.
Sextus Empiricus (c. 200 CE), the main authority for Pyrrhonian skepticism, worked outside the Academy, which by his time had ceased to be a skeptical or probabilistic school, and argued in a different direction, incorporating aspects of empiricism into the basis for evaluating knowledge, but without the insistence on experience as the absolute standard of it. Sextus' empiricism was limited to the "absolute minimum" already mentioned — that there seem to be appearances. He developed this basic thought of Pyrrho's into lengthy arguments, most of them directed against Stoics and Epicureans, but also the Academic skeptics. The common anti-skeptical argument is that if one knows nothing, one cannot know that one knows nothing, and so may know something after all. It is worth noting that such an argument only succeeds against the complete denial of the possibility of knowledge. Considering dogmatic the claims both to know and not to know, Sextus and his followers claimed neither. Instead, despite the apparent conflict with the goal of ataraxia, they claimed to continue searching for something that might be knowable.
Empiricus, as the most systematic and dogmatic author of the works by Hellenistic sceptics which have survived, noted that there are at least ten modes of skepticism. These modes may be broken down into three categories: we may be skeptical of the subjective perceiver, of the objective world, and the relation between perceiver and the world.
Subjectively, both the powers of the senses and of reasoning may vary across persons. And since knowledge is a product of one and/or the other, and since neither are reliable, knowledge would seem to be in trouble. For instance, a color-blind person sees the world quite differently from everyone else. Moreover, we cannot even give preference on the basis of the power of reason, i.e., by treating the rational animal as a carrier of greater knowledge than the irrational animal. For the irrational animal is still adept at navigating their environment, which presupposes the ability to know about some aspects of the environment.
Secondly, the personality of the individual might also have an impact on what they observe, since (it is argued) preferences are based on sense-impressions, differences in preferences can be attributed to differences in the way that people are affected by the object. (Empiricus:56)
Third, the perceptions of each individual sense seemingly have nothing in common with the other senses: i.e., the color "red" has little to do with the feeling of touching a red object. This is manifest when our senses "disagree" with each other: for example, a mirage presents certain visible features, but is not responsive to any other kind of sense. In that case, our other senses defeat the impressions of sight. But we may also be lacking enough powers of sense to understand the world in its entirety: if we had an extra sense, then we might know of things in a way that the present five senses are unable to advise us of. Given that our senses can be shown to be unreliable by appealing to other senses, and so our senses may be incomplete (relative to some more perfect sense that we lack), then it follows that all of our senses may be unreliable. (Empiricus:58)
Fourth, our circumstances when we do any perceiving may be either natural or unnatural, i.e., we may be either in a state of wakefulness or that of sleep. But it is entirely possible that things in the world really are exactly as they appear to be to those in unnatural states (i.e., if everything were an elaborate dream). (Empiricus:59)
We have reasons for doubt that are based on the relationship between objective "facts" and subjective experience. The positions, distances, and places of objects would seem to affect how they are perceived by the person: for instance, the portico may appear tapered when viewed from one end, but symmetrical when viewed at the other; and these features are different. Because they are different features, to believe the object has both properties at the same time is to believe it has two contradictory properties. Since this is absurd, we must suspend judgment about what properties it possesses. (Empiricus:63)
We may also observe that the things we perceive are, in a sense, polluted by experience. Any given perception—say, of a chair—will always be perceived within some context or other (i.e., next to a table, on a mat, etc.) Since this is the case, we can only speak of ideas as they occur in the context of the other things that are paired with it. We can never know of the true nature of the thing, but only how it appears to us in context. (Empiricus: 64)
Along the same lines, the skeptic may insist that all things are relative, by arguing that:
- Absolute appearances either differ from relative appearances, or they do not.
- If absolutes do not differ from relatives, then they are themselves relative.
- But if absolutes do differ from relatives, then they are relative, because all things that differ must differ from something; and to "differ" from something is to be relative to something. (Empiricus:67)
Finally, we have reason to disbelieve that we know anything by looking at problems in understanding the objects themselves. Things, when taken individually, may appear to be very different than when they are in mass quantities: for instance, the shavings of a goat's horn are white when taken alone, yet the horn intact is black.
Ancient Eastern Skepticism
Buddhist skepticism (Zen Buddhism) is not concerned with whether a thing exists or not. The Zen masters would answer questions "koans" with seemingly unrelated responses such as hitting the student. This would serve as a means of pulling the student back from the confusion of intellectual pontification, and into a direct experience. Since in Zen, all there is a direct experience, which cannot be explained or clarified beyond the experience itself, this answers the question.
- Buddha is said to have touched the earth at the time of his enlightenment so that it could witness his enlightenment. In this way, Buddhism does not claim that knowledge is unattainable.
- Buddhism places less emphasis on truth and knowledge than western philosophical skepticism. Instead, it emphasizes the goal of Bodhi, which, although often translated as enlightenment, does not imply truth or knowledge.
- At least in its manifestation of Nagarjuna's texts that form the core of Madhyamaka, the anti-essentialist aspect of Buddhism makes it an anti-philosophy.[dubious ]From that stance, truth exists solely within the contexts that assert them.
The Cārvāka (Sanskrit: चार्वाक) school of skepticism, also known as Lokāyata, is a distinct branch of Indian philosophy. The school is named after Cārvāka, author of the Bārhaspatya-sūtras and was founded in approximately 500 BC. Cārvāka is classified as a "heterodox" (nāstika) system, characterized as a materialistic and atheistic school of thought.
Jain Philosophy of Anekantavada and Syadavada
Anekāntavāda also known as the principle of relative pluralism, is one of the basic principles of Jainism. According to this, the truth or the reality is perceived differently from different points of view, and that no single point of view is the complete truth. Jain doctrine states that, an object has infinite modes of existence and qualities and, as such, they cannot be completely perceived in all its aspects and manifestations, due to inherent limitations of the humans. Anekāntavāda is literally the doctrine of non-onesidedness or manifoldness; it is often translated as "non-absolutism". Syādvāda is the theory of conditioned predication which provides an expression to anekānta by recommending that epithet “Syād” be attached to every expression. Syādvāda is not only an extension of Anekānta ontology, but a separate system of logic capable of standing on its own force. As reality is complex, no single proposition can express the nature of reality fully. Thus the term “syāt” should be prefixed before each proposition giving it a conditional point of view and thus removing any dogmatism in the statement. . The seven propositions also known as saptabhangi are
- Syād-asti – “in some ways it is”,
- syād-nāsti - “in some ways it is not”,
- syād-asti-nāsti - “in some ways it is and it is not”,
- syād-asti-avaktavyaḥ - “in some ways it is and it is indescribable”,
- syād-nāsti-avaktavyaḥ - “in some ways it is not and it is indescribable”,
- syād-asti-nāsti-avaktavyaḥ - “in some ways it is, it is not and it is indescribable”,
- syād-avaktavyaḥ- “in some ways it is indescribable”
Each of these seven propositions examines the complex and multifaceted reality from a relative point of view of time, space, substance and mode. To ignore the complexity of the objects is to commit the fallacy of dogmatism. For a rigorous logical and mathematical interpretation see M. K. Jain, Current Science.100, 1663-1672 (2011).
In China, the preeminent Daoist work Zhuangzi, attributed to 4th century BC philosopher Zhuangzi during the Hundred Schools of Thought period, is skeptical in nature and provides also two famous skeptical paradoxes, "The Happiness of Fish" and "Zhuangzi dreamed he was a butterfly".
Wang Chong introduced a form of naturalism based on a rational critique of the superstition that was overtaking Confucianism and Daoism in the 1st century CE. His neo-Daoist philosophy was based on a secular, rational practice not unlike the scientific method.
In Islamic theology and Islamic philosophy, the scholar Al-Ghazali (1058–1111) is considered a pioneer of methodic doubt and skepticism.[not in citation given] His 11th century book titled The Incoherence of the Philosophers marks a major turn in Islamic epistemology, as Ghazali effectively discovered a methodic form of philosophical skepticism that would not be commonly seen in the West until René Descartes, George Berkeley and David Hume. The encounter with skepticism led Ghazali to embrace a form of theological occasionalism, or the belief that all causal events and interactions are not the product of material conjunctions but rather the immediate and present will of God. While he himself was a critic of the philosophers, Ghazali was a master in the art of philosophy and had immensely studied the field. After such a long education in philosophy, as well as a long process of reflection, he had criticized the philosophical method.
The autobiography Ghazali wrote towards the end of his life, The Deliverance From Error (Al-munqidh min al-ḍalāl; several English translations) is considered a work of major importance. In it, Ghazali recounts how, once a crisis of epistemological skepticism was resolved by "a light which God Most High cast into my breast...the key to most knowledge," he studied and mastered the arguments of Kalam, Islamic philosophy and Ismailism. Though appreciating what was valid in the first two of these, at least, he determined that all three approaches were inadequate and found ultimate value only in the mystical experience and spiritual insight (Spiritual intuitive thought – Firasa and Nur) he attained as a result of following Sufi practices. William James, in Varieties of Religious Experience, considered the autobiography an important document for "the purely literary student who would like to become acquainted with the inwardness of religions other than the Christian", comparing it to recorded personal religious confessions and autobiographical literature in the Christian tradition.
Scholars have noted the similarities between Descartes' Discourse on Method and Ghazali's work and the writer George Henry Lewes went even further by claiming that "had any translation of it [The Revival of Religious Sciences] in the days of Descartes existed, everyone would have cried out against the plagiarism."[not in citation given]
Schools of philosophical skepticism
Philosophical skepticism begins with the claim that the skeptic currently does not have knowledge. Some adherents maintain that knowledge is, in theory, possible. It could be argued that Socrates held that view. He appears to have thought that if people continue to ask questions they might eventually come to have knowledge; but that they did not have it yet. Some skeptics have gone further and claimed that true knowledge is impossible, for example the Academic school in Ancient Greece well after the time of Carneades. A third skeptical approach would be neither to accept nor reject the possibility of knowledge.
Skepticism can be either about everything or about particular areas. A 'global' skeptic argues that he does not absolutely know anything to be either true or false. Academic global skepticism has great difficulty in supporting this claim while maintaining philosophical rigor, since it seems to require that nothing can be known — except for the knowledge that nothing can be known, though in its probabilistic form it can use and support the notion of weight of evidence. Thus, some probabilists avoid extreme skepticism by maintaining that they merely are 'reasonably certain' (or 'largely believe') some things are real or true. As for using probabilistic arguments to defend skepticism, in a sense this enlarges or increases scepticism, while the defence of empiricism by Empiricus weakens skepticism and strengthens dogmatism by alleging that sensory appearances are beyond doubt. Much later, Kant would re-define "dogmatism" to make indirect realism about the external world seem objectionable. While many Hellenists, outside of Empiricus, would maintain that everyone who is not sceptical about everything is a dogmatist, this position would seem too extreme for most later philosophers.
Nevertheless, A Pyrrhonian global skeptic labors under no such modern constraint, since he only alleged that he, personally, did not know anything and made no statement about the possibility of knowledge. Nor did Arcesilaus feel bound, since he merely corrected Socrates's "I only know that I know nothing" by adding "I don't even know that", thus more fully rejecting dogmatism.
Local skeptics deny that people do or can have knowledge of a particular area. They may be skeptical about the possibility of one form of knowledge without doubting other forms. Different kinds of local skepticism may emerge, depending on the area. A person may doubt the truth value of different types of journalism, for example, depending on the types of media they trust.
In the West itself, the one Renaissance thinker mostly viewed as the "Father of Modern Skepticism" is Michel de Montaigne, especially in his seminal Essays. Francisco Sanches's That Nothing is Known (published in 1581 as Quod nihil scitur) is also one of the crucial texts of Renaissance skepticism.
Epistemology and skepticism
Skepticism, as an epistomological argument, poses the question of whether knowledge, in the first place, is possible. Skeptics argue that the belief in something does not necessarily justify an assertion of knowledge of it. In this, skeptics oppose dogmatic foundationalism, which states that there have to be some basic positions that are self-justified or beyond justification, without reference to others. (One example of such foundationalism may be found in Spinoza's Ethics.) The skeptical response to this can take several approaches. First, claiming that "basic positions" must exist amounts to the logical fallacy of argument from ignorance combined with the slippery slope.
Among other arguments, skeptics used Agrippa's Trilemma, named after Agrippa the Sceptic, to claim no certain belief could be achieved. Foundationalists have used the same trilemma as a justification for demanding the validity of basic beliefs.
This skeptical approach is rarely taken to its pyrrhonean extreme by most practitioners. Several modifications have arisen over the years, including the following :
Fictionalism would not claim to have knowledge but will adhere to conclusions on some criterion such as utility, aesthetics, or other personal criteria without claiming that any conclusion is actually "true".
Philosophical fideism (as opposed to religious Fideism) would assert the truth of some propositions, but does so without asserting certainty.
Some forms of pragmatism would accept utility as a provisional guide to truth but not necessarily a universal decision-maker.
Criticism of skepticism
Most philosophies have weaknesses and can be criticized and this is a general principle of progression in philosophy. The philosophy of skepticism asserts that no truth is knowable or only probable. Some say the scientific method also asserts probable findings, because the number of cases tested is always limited and they constitute perceptual observations. To claim that the proposition “no truth is knowable” is knowably true is to refute oneself; as it is contradictory.
Pierre Le Morvan (2011) has distinguished between three broad philosophical approaches to skepticism. The first he calls the "Foil Approach." According to the latter, skepticism is treated as a problem to be solved, or challenge to be met, or threat to be parried; skepticism‘s value on this view, insofar as it is deemed to have one, accrues from its role as a foil contrastively illuminating what is required for knowledge and justified belief. The second he calls the "Bypass Approach" according to which skepticism is bypassed as a central concern of epistemology. Le Morvan advocates a third approach—he dubs it the "Health Approach"—that explores when skepticism is healthy and when it is not, or when it is virtuous and when it is vicious.
A skeptical hypothesis is a hypothetical situation which can be used in an argument for skepticism about a particular claim or class of claims. Usually the hypothesis posits the existence of a deceptive power that deceives our senses and undermines the justification of knowledge otherwise accepted as justified. Skeptical hypotheses have received much attention in modern Western philosophy.
The first skeptical hypothesis in modern Western philosophy appears in René Descartes' Meditations on First Philosophy. At the end of the first Meditation Descartes writes: "I will suppose... that some evil demon of the utmost power and cunning has employed all his energies to deceive me."
- The "Brain in a vat" hypothesis is cast in scientific terms. It supposes that one might be a disembodied brain kept alive in a vat, and fed false sensory signals, by a mad scientist.
- The "Dream argument" of Descartes and Zhuangzi supposes reality to be indistinguishable from a dream.
- Descartes' Evil demon is a being "as clever and deceitful as he is powerful, who has directed his entire effort to misleading me."
- The five minute hypothesis (or omphalos hypothesis or Last Thursdayism) suggests that the world was created recently together with records and traces indicating a greater age.
- The Simulated reality hypothesis or "Matrix hypothesis" suggest that we might be inside a computer simulation or virtual reality.
- Abuses of skepticism
- Benson Mates
- Brain in a vat
- David Hume
- Dream argument
- Five minute hypothesis
- Here is one hand - a response to skepticism
- Münchhausen Trilemma
- Problem of the criterion
- Problem of induction
- Sextus Empiricus
- Simulated reality
- Diogenes Laërtius 9:80-88
- On the ten modes, see Sextus Empiricus. Outlines of Skepticism I.35-164.
- Dundas, Paul; John Hinnels ed. (2002). The Jains. London: Routledge. ISBN 0-415-26606-8.
- Koller, John M. (July 2000). "Syadvada as the Epistemological Key to the Jaina Middle Way Metaphysics of Anekantavada". Philosophy East and West (Honululu) 50 (3): 400–7. doi:10.1353/pew.2000.0009. ISSN 0031-8221. JSTOR 1400182.
- Chatterjea, Tara (2001). Knowledge and Freedom in Indian Philosophy. Lanham, MD: Lexington Books. ISBN 739106929 Check
|isbn=value (help). p. 77-87
- Koller, John M. (July 2000). "Syādvāda as the [[epistemological]] key to the Jaina middle way metaphysics of Anekāntavāda". Philosophy East and West. (Honululu) 50 (3): 400–8. ISSN 0031-8221. Retrieved 2007-10-01. Wikilink embedded in URL title (help)
- Grimes, John (1996). A Concise Dictionary of Indian Philosophy: Sanskrit Terms Defined in English. New York: SUNY Press. ISBN 0-7914-3067-7. p. 312
- Najm, Sami M. (July–October 1966). "The Place and Function of Doubt in the Philosophies of Descartes and Al-Ghazali". Philosophy East and West (Philosophy East and West, Vol. 16, No. 3/4) 16 (3–4): 133–411. doi:10.2307/1397536. JSTOR 1397536
- Annotated translations by Richard Joseph McCarthy (Freedom and Fulfillment, Boston: Twayne, 1980; Deliverance From Error, Louisville, Ky.: Fons Vitae, 1999) and George F. McLean (Deliverance from error and mystical union with the Almighty, Washington, D.C.: Council for Research in Values and Philosophy, 2001). An earlier translation by William Montgomery Watt was first published in 1953 (The faith and practice of al-Ghazālī, London: G. Allen and Unwin).
- Gerhard Böwering, Encyclopedia Iranica, s.v. Ghazali.
- McCarthy 1980, p. 66
- William James, Varieties of Religious Experience, Harvard University Press, 1985, p. 319 [= 2002 Modern Library Paperback Edition, p. 438].
- Lewes, George Henry (1867). The History of Philosophy from Thales to Comte, Vol. 2: Modern Philosophy. London: Longmans, Green, and Co.
- Francisco Sanchez, That Nothing is Known, Cambridge University Press, 1989.
- Popkin, H and Stroll, A. Philosophy Made Simple’’ Broadway Books, NY, NY 1993
- Kreeft, Peter & Tacelli, R. K Handbook of Christian Apologetics, IVP Academic, Ill. 1994, p. 367)
- Popkin, p. 205
- Popkin, p. 230
- Kreeft p. 373
- Breker, Christian: Einführender Kommentar zu Sextus Empiricus' "Grundriss der pyrrhonischen Skepsis", Mainz, 2011: electr. publication, University of Mainz. available online (comment on Sextus Empiricus’ “Outlines of Pyrrhonism” in German language)
- Zeller, Eduard; Reichel, Oswald J., The Stoics, Epicureans and Sceptics, Longmans, Green, and Co., 1892
- Responses to skepticism
- Excerpts from the "Outlines of Pyrrhonism" by Sextus Empiricus
- Skepticism entry in the Stanford Encyclopedia of Philosophy
- Attempted refutation of external-world scepticism. On-line version of two recently published books by philosopher Olaf M. Müller (in German)
- Article: Skepticism and Denial by Stephen Novella MD, The New England Journal of Skepticism
- Classical Skepticism by Peter Suber.
- The Matrix as Metaphysics by David Chalmers
- Review and summary of Skepticism and the Veil of Perception by Mike Huemer