Skepticism (American English) or scepticism (British English, Australian English, and Canadian English) is generally any questioning attitude or doubt towards one or more items of putative knowledge or belief.[1][2] It is often directed at domains, such as the supernatural, morality (moral skepticism), religion (skepticism about the existence of God), or knowledge (skepticism about the possibility of knowledge, or of certainty).[3] Formally, skepticism as a topic occurs in the context of philosophy, particularly epistemology, although it can be applied to any topic such as politics, religion, and pseudoscience.

Philosophical skepticism comes in various forms. Radical forms of skepticism deny that knowledge or rational belief is possible and urge us to suspend judgment on many or all controversial matters. More moderate forms of skepticism claim only that nothing can be known with certainty, or that we can know little or nothing about the "big questions" in life, such as whether God exists or whether there is an afterlife. Religious skepticism is "doubt concerning basic religious principles (such as immortality, providence, and revelation)".[4] Scientific skepticism concerns testing beliefs for reliability, by subjecting them to systematic investigation using the scientific method, to discover empirical evidence for them.


In ordinary usage, skepticism (US) or scepticism (UK) (Greek: 'σκέπτομαι' skeptomai, to search, to think about or look for; see also spelling differences) can refer to:

  1. an attitude of doubt or a disposition to incredulity either in general or toward a particular object;
  2. the doctrine that true knowledge or some particular knowledge is uncertain;
  3. the method of suspended judgment, systematic doubt, or criticism that is characteristic of skeptics (Merriam–Webster).

In philosophy, skepticism can refer to:

  1. a mode of inquiry that emphasizes critical scrutiny, caution, and intellectual rigor;
  2. a method of obtaining knowledge through systematic doubt and continual testing;
  3. a set of claims about the limitations of human knowledge and the proper response to such limitations.

Philosophical skepticism

As a philosophical school or movement, skepticism originated in ancient Greece. A number of Greek Sophists held skeptical views. Gorgias, for example, reputedly argued that nothing exists, that even if there were something we could not know it, and that even if we could know it we could not communicate it.[5] Another Sophist, Cratylus, refused to discuss anything and would merely wriggled his finger, claiming that communication is impossible since meanings are constantly changing.[6] The Sophists' leading critic, Socrates, also had skeptical tendencies, claiming that he knew nothing, or at least nothing worthwhile.[7]

There were two major schools of skepticism in the ancient Greek and Roman world. One was Pyrrhonian skepticism, which was founded by Pyrrho of Elis (c. 360–270 BCE). The other was Academic skepticism, so-called because its two leading defenders, Arcesilaus (c. 315–240 BCE) and Carneades (c. 217–128 BCE) were Heads of Plato's Academy. Both schools of skepticism denied that knowledge is possible and urged suspension of judgment (epoche) for the sake of mental tranquility (ataraxia). The major difference between the schools seems to have been that Academic skeptics claimed that some beliefs are more reasonable or probable than others, whereas Pyrrhonian skeptics argued that equally compelling arguments can be given for or against any disputed view.[8] Nearly all the writings of the ancient skeptics are now lost. Most of what we know about ancient skepticism is due to Sextus Empiricus, a Pyrrhonian skeptic who lived in the second or third century A.D. His major work, Outlines of Pyrrhonism, contains a lucid summary of stock skeptical arguments.

Ancient skepticism faded out during the late Roman Empire, particularly after Augustine (354–430 CE) attacked the skeptics in his work Against the Academics (386 CE). There was little knowledge of, or interest in, ancient skepticism in Christian Europe during the Middle Ages. Interest revived during the Renaissance and Reformation, particularly after the complete writings of Sextus Empiricus were translated into Latin in 1569. A number of Catholic writers, including Francisco Sanches (c. 1550–1623), Michel de Montaigne (1533–1592), Pierre Gassendi (1592–1655), and Marin Mersenne (1588–1648) deployed ancient skeptical arguments to defend moderate forms of skepticism and to argue that faith, rather than reason, must be the primary guide to truth. Similar arguments were offered later (perhaps ironically) by the Protestant thinker Pierre Bayle in his influential Historical and Critical Dictionary (1697–1702).[9]

The growing popularity of skeptical views created an intellectual crisis in seventeenth-century Europe. One major response was offered by the French philosopher and mathematician René Descartes (1596–1650). In his classic work, Meditations of First Philosophy (1641), Descartes sought to refute skepticism, but only after he had formulated the case for skepticism as powerfully as possible. Descartes argued that no matter what radical skeptical possibilities we imagine there are certain truths (e.g., that thinking is occurring, or that I exist) that are absolutely certain. Thus, the ancient skeptics were wrong to claim that knowledge is impossible. Descartes also attempted to refute skeptical doubts about the reliability of our senses, our memory, and other cognitive faculties. To do this, Descartes tried to prove that God exists and that God would not allow us to be systematically deceived about the nature of reality. Many contemporary philosophers question whether this second stage of Descartes’ critique of skepticism is successful.[10]

In the eighteenth century a powerful new case for skepticism was offered by the Scottish philosopher David Hume (1711–1776). Hume was an empiricist, claiming that all genuine ideas can be traced back to original impressions of sensation or introspective consciousness. Hume argued forcefully that on empiricist grounds there are no sound reasons for belief in God, an enduring self or soul, an external world, causal necessity, objective morality, or inductive reasoning. In fact, he argued that "Philosophy would render us entirely Pyrrhonian, were not Nature too strong for it."[11] As Hume saw it, the real basis of human belief is not reason, but custom or habit. We are hard-wired by nature to trust, say, our memories or inductive reasoning, and no skeptical arguments, however powerful, can dislodge those beliefs. In this way, Hume embraced what he called a "mitigated" skepticism, while rejecting an "excessive" Pyrrhonian skepticism that he saw as both impractical and psychologically impossible.

Hume's skepticism provoked a number of important responses. Hume's Scottish contemporary, Thomas Reid (1710–1796), challenged Hume's strict empiricism and argued that it is rational to accept "common-sense" beliefs such as the basic reliability of our senses, our reason, our memories, and inductive reasoning, even though none of these things can be proved. In Reid's view, such common-sense beliefs are foundational and require no proof in order to be rationally justified.[12] Not long after Hume's death, the great German philosopher Immanuel Kant (1724–1804) argued that human moral awareness makes no sense unless we reject Hume’s skeptical conclusions about the existence of God, the soul, free will, and an afterlife. According to Kant, while Hume was right to claim that we cannot strictly know any of these things, our moral experience entitles us to believe in them.[13]

Today, skepticism continues to be a topic of lively debate among philosophers.[14]

Religious skepticism

Religious skepticism generally refers to doubting given religious beliefs or claims. Historically, religious skepticism can be traced back to Socrates, who doubted many religious claims of the time. Modern religious skepticism typically emphasizes scientific and historical methods or evidence, with Michael Shermer writing that skepticism is a process for discovering the truth rather than general non-acceptance. For example, a religious skeptic might believe that Jesus existed while questioning claims that he was the messiah or performed miracles (see historicity of Jesus). Religious skepticism is not the same as atheism or agnosticism, though these often do involve skeptical attitudes toward religion and philosophical theology (for example, towards divine omnipotence). Religious people are generally skeptical about claims of other religions, at least when the two denominations conflict concerning some stated belief. Additionally, they may also be skeptical of the claims made by atheists.[15] The historian Will Durant writes that Plato was "as skeptical of atheism as of any other dogma".

Scientific skepticism

A scientific or empirical skeptic is one who questions beliefs on the basis of scientific understanding and empirical evidence.

Scientific skepticism may discard beliefs pertaining to purported phenomena not subject to reliable observation and thus not systematic or testable empirically. Most scientists, being scientific skeptics, test the reliability of certain kinds of claims by subjecting them to a systematic investigation using some type of the scientific method.[16] As a result, a number of claims are considered as "pseudoscience", if they are found to improperly apply or ignore the fundamental aspects of the scientific method.

Professional skepticism

Professional skepticism is an important concept in auditing. It requires an auditor to have a "questioning mind", to make a critical assessment of evidence, and to consider the sufficiency of the evidence.[17]

See also


  1. ^ Popkin, R. H. The History of Skepticism from Erasmus to Descartes (rev. ed. 1968); C. L. Stough, Greek Skepticism (1969); M. Burnyeat, ed., The Skeptical Tradition (1983); B. Stroud, The Significance of Philosophical Skepticism (1984).
  2. ^ "Philosophical views are typically classed as skeptical when they involve advancing some degree of doubt regarding claims that are elsewhere taken for granted."
  3. ^ Greco, John (2008). The Oxford Handbook of Skepticism. Oxford University Press, US. ISBN 9780195183214.
  4. ^ "Definition of SKEPTICISM". Retrieved 2016-02-05.
  5. ^ W. T. Jones, A History of Western Philosophy. New York: Harcourt, Brace, 1952, p. 60 n. 45.
  6. ^ Richard H. Popkin, "Skepticism", in Paul Edwards, ed., The Encyclopedia of Philosophy, vol. 7. New York: Macmillan, 1967, p. 449.
  7. ^ Allan Hazlett, A Critical Introduction to Skepticism. London: Bloomsbury, 2014, p. 5.
  8. ^ Popkin, "Skepticism", p. 450.
  9. ^ Richard H. Popkin, The History of Skepticism from Erasmus to Spinoza, rev. ed. Berkeley: University of California Press, 1979, chaps 1 and 2.
  10. ^ See, e.g., Popkin, The History of Skepticism, p. 210.
  11. ^ Quoted in Popkin, "Skepticism", p. 456.
  12. ^ Popkin, "Skepticism", p. 456.
  13. ^ Popkin, "Skepticism", p. 457.
  14. ^ See, e.g., John Greco, ed., The Oxford Handbook of Skepticism. New York: Oxford University Press, 2008.
  15. ^ Mann, Daniel. "Skeptical of Atheism". Apologetics for Today. Retrieved 2 December 2013.
  16. ^ "Scientific Skepticism, CSICOP, and the Local Groups - CSI". Retrieved 2018-07-05.
  17. ^ "AU 230 Due Professional Care in the Performance of Work". Retrieved 2018-04-28.


Further reading

External links

Cartesian doubt

Cartesian doubt is a form of methodological skepticism associated with the writings and methodology of René Descartes (1596–1650). Cartesian doubt is also known as Cartesian skepticism, methodic doubt, methodological skepticism, universal doubt, systematic doubt or hyperbolic doubt.

Cartesian doubt is a systematic process of being skeptical about (or doubting) the truth of one's beliefs, which has become a characteristic method in philosophy. This method of doubt was largely popularized in Western philosophy by René Descartes, who sought to doubt the truth of all his beliefs in order to determine which beliefs he could be certain were true. It is the basis for Descartes' statement, "Cogito ergo sum" ("I think, therefore I am").

Methodological skepticism is distinguished from philosophical skepticism in that methodological skepticism is an approach that subjects all knowledge claims to scrutiny with the goal of sorting out true from false claims, whereas philosophical skepticism is an approach that questions the possibility of certain knowledge.

Chinese views of democracy

Chinese scholars, thinkers, and policy-makers have debated about democracy, an idea which was first imported by Western colonial powers but which some argue also has connections to classic Chinese thinking. Starting in the mid-eighteenth century, many Chinese argued about how to deal with the ever-encroaching Western culture. Though Chinese Confucians were initially opposed to Western modes of thinking, it became clear that aspects of the West were appealing. Industrialization gave the West an economic and military advantage. The devastating defeats of the First and Second Opium Wars compelled a segment of Chinese politicians and intellectuals to rethink their notion of cultural and political superiority.Democracy entered the Chinese consciousness because it was the form of government used in the West, potentially responsible for its industrial, economic and military advancements. A segment of Chinese scholars and politicians became persuaded that democratization and industrialization were imperative for a competitive China. In response, a number of scholars resisted the idea, saying democracy and Westernization had no place in traditional Chinese culture. Liang Shuming's opinion was most popular, holding that democracy and traditional Chinese society were completely incompatible, hence China’s only choice was either wholesale Westernization or complete rejection of the West. The debate centered on the philosophical compatibility of traditional Chinese Confucian beliefs and the technologies of the West.

Climate change denial

Climate change denial, or global warming denial, is part of the global warming controversy. It involves denial, dismissal, or unwarranted doubt that contradicts the scientific opinion on climate change, including the extent to which it is caused by humans, its impacts on nature and human society, or the potential of adaptation to global warming by human actions. Some deniers endorse the term, while others prefer the term climate change skepticism. Several scientists have noted that "skepticism" is an inaccurate description for those who deny anthropogenic global warming. In effect, the two terms form a continuous, overlapping range of views, and generally have the same characteristics: both reject, to a greater or lesser extent, the scientific consensus on climate change. Climate change denial can also be implicit, when individuals or social groups accept the science but fail to come to terms with it or to translate their acceptance into action. Several social science studies have analyzed these positions as forms of denialism and pseudoscience.The campaign to undermine public trust in climate science has been described as a "denial machine" organized by industrial, political and ideological interests, and supported by conservative media and skeptical bloggers to manufacture uncertainty about global warming. In the public debate, phrases such as climate skepticism have frequently been used with the same meaning as climate denialism. The labels are contested: those actively challenging climate science commonly describe themselves as "skeptics", but many do not comply with common standards of scientific skepticism and, regardless of evidence, persistently deny the validity of human caused global warming.Although scientific opinion on climate change is that human activity is extremely likely to be the primary driver of climate change, the politics of global warming have been affected by climate change denial, hindering efforts to prevent climate change and adapt to the warming climate. Those promoting denial commonly use rhetorical tactics to give the appearance of a scientific controversy where there is none.Of the world's countries, the climate change denial industry is most powerful in the United States. From 2015 to 2017 (after having already served from 2003 to 2007), the United States Senate Committee on Environment and Public Works was chaired by oil lobbyist and climate change denier Jim Inhofe, who had previously called climate change "the greatest hoax ever perpetrated against the American people" and claimed to have debunked the alleged hoax in February 2015 when he brought a snowball with him in the Senate chamber and tossed it across the floor. He was succeeded in 2017 by John Barrasso, who similarly said: "The climate is constantly changing. The role human activity plays is not known." Organised campaigning to undermine public trust in climate science is associated with conservative economic policies and backed by industrial interests opposed to the regulation of CO2 emissions. Climate change denial has been associated with the fossil fuels lobby, the Koch brothers, industry advocates and conservative think tanks, often in the United States. More than 90% of papers sceptical on climate change originate from right-wing think tanks.

The total annual income of these climate change counter-movement-organizations is roughly $900 million. Between 2002 and 2010, nearly $120 million (£77 million) was anonymously donated via the Donors Trust and Donors Capital Fund to more than 100 organisations seeking to undermine the public perception of the science on climate change. In 2013 the Center for Media and Democracy reported that the State Policy Network (SPN), an umbrella group of 64 U.S. think tanks, had been lobbying on behalf of major corporations and conservative donors to oppose climate change regulation.Since the late 1970s, oil companies have published research broadly in line with the standard views on global warming. Despite this, oil companies organized a climate change denial campaign to disseminate public disinformation for several decades, a strategy that has been compared to the organized denial of the hazards of tobacco smoking by the tobacco industry.

Environmental skepticism

Environmental skepticism is the belief that claims by environmentalists, and the environmental scientists who support them, are false or exaggerated. The term is also applied to those who are critical of environmentalism in general. It can additionally be defined as doubt about the authenticity or severity of environmental degradation. Environmental skepticism is closely linked with anti-environmentalism and climate change denial.


Epistemology ( (listen); from Greek, Modern ἐπιστήμη, epistēmē, meaning 'knowledge', and λόγος, logos, meaning 'the study of [a certain subject]') is the branch of philosophy concerned with the theory of knowledge.Epistemology is the study of the nature of knowledge, justification, and the rationality of belief. Much debate in epistemology centers on four areas: (1) the philosophical analysis of the nature of knowledge and how it relates to such concepts as truth, belief, and justification, (2) various problems of skepticism, (3) the sources and scope of knowledge and justified belief, and (4) the criteria for knowledge and justification. Epistemology addresses such questions as: "What makes justified beliefs justified?", "What does it mean to say that we know something?", and fundamentally "How do we know that we know?"

List of scientific skeptics

This is a list of notable people that promote or practice scientific skepticism. In general, they favor science and are opposed to pseudoscience and quackery. They are generally skeptical of parapsychology, the paranormal, and alternative medicine.

James Alcock, psychologist. Author of several skeptical books and articles.

Isaac Asimov, biochemist, author. Wrote or edited over 500 popular science, other nonfiction, and science fiction books, including the Foundation series. Founding member of CSICOP (now CSI).

Robert A. Baker, psychologist, author. Wrote books on ghosts, alien abductions and false memory syndrome.

Banachek, mentalist. participant in Project Alpha. Real name Steve Shaw

Stephen Barrett, psychiatrist. Cofounder of the National Council Against Health Fraud, critic of alternative medicine. Founder of the Quackwatch website.

Barry Beyerstein, psychologist. Founding member of CSICOP (now CSI).

Susan Blackmore, parapsychologist. Author, lecturer, and broadcaster.

Maarten Boudry, philosopher and author.

Derren Brown, mentalist, critic of alleged psychics and spiritual mediums.

Robert Todd Carroll, philosopher. Author of The Skeptic's Dictionary book and website.

Milbourne Christopher, magician. Founding member of CSICOP (now CSI).

Derek Colanduno and Robynn McCarthy, co-hosts of the podcast Skepticality: The Official Podcast of Skeptic Magazine.

David Colquhoun, pharmacologist and author of the website Improbable Science.

Brian Cox, physicist

Narendra Dabholkar, author and the founder-president of Maharashtra Andhashraddha Nirmoolan Samiti.

Richard Dawkins, evolutionary biologist and author known for promoting the gene-centric view of evolution (in his book The Selfish Gene), coining of the term meme, and atheist activism.

Perry DeAngelis, co-founder and former executive director of the New England Skeptical Society, co-founder and former co-host of the Skeptics' Guide to the Universe podcast.

Daniel Dennett, philosopher. Author of Darwin's Dangerous Idea: Evolution and the Meanings of Life and Breaking the Spell: Religion as a Natural Phenomenon.

Jared Diamond, scientist, author and member of the editorial board of Skeptic.

Ann Druyan, popular science author and current head of the Planetary Society. Widow of the astronomer Carl Sagan.

Brian Dunning, writer and producer with focus on science and skepticism, host of Skeptoid podcast, as well as a Skeptoid spin-off video series, inFact, and producer of educational films on the subject of critical thinking.

Mark Edward, formerly worked as a psychic, currently exposes psychics and is the author of a tell-all book on that subject, member of editorial board of The Skeptics Society, invented the term Guerrilla Skepticism.

Richard Feynman, theoretical physicist known for his work in quantum mechanics.

Kendrick Frazier, Editor of the Skeptical Inquirer.

Martin Gardner, author, recreational mathematician. Writer of the long-running 'Mathematical Games' column in Scientific American, and a longstanding columnist for the Skeptical Inquirer. Founding member of CSICOP (now CSI).

Pamela L. Gay, astronomer, co-host of Astronomy Cast, assistant research professor in the STEM center at SIUE and project director for CosmoQuest.

Susan Gerbic, the founder of Guerrilla Skepticism on Wikipedia which has the mission of improving the skeptical content of Wikipedia.

Ben Goldacre, physician, journalist. Author of the "Bad Science" column in The Guardian (UK newspaper).

David Gorski, surgical oncologist. A.k.a. Orac of Respectful Insolence. Critic of complimentary and alternative medicine.

Stephen Jay Gould, paleontologist, evolutionary biologist, historian of science, Harvard University.

Natalie Grams, German physician, writer, scientific skeptic, former homeopath, author of Homeopathy Reconsidered — What Really Helps Patients (in German)

Harriet A. Hall, physician, former US Air Force flight surgeon. Critic of alternative medicine and quackery.

Sven Ove Hansson, philosopher. Founding Chairperson of the Swedish Skeptics (Vetenskap och Folkbildning) and Editor of the organisation's journal Folkvett.

Sam Harris, neuroscientist and author.

Sharon A. Hill, founder of Doubtful News, a news site that links synopses and commentary to original news sources, and provides information to critically assess claims made in the media. She is also producer and host of the 15 Credibility Street podcast.

Christopher Hitchens, journalist and author.

Douglas Hofstadter, physicist, artificial intelligence researcher. Author of Pulitzer Prize-winning book Gödel, Escher, Bach: The Eternal Golden Braid and Scientific American column "Metamagical Themas".

Harry Houdini, magician. Critic of Modern Spiritualism who exposed fraudulent psychics and mediums and publicized their methods.

George Hrab American skeptical musician, podcaster, speaker and emcee at The Amaz!ng Meeting

Ray Hyman, psychologist, critic of parapsychology. Longstanding contributor to the Skeptical Inquirer. Founding member of CSICOP (now CSI).

Jamie Hyneman, co-creator of the TV show MythBusters.

Leo Igwe, Nigerian human rights advocate.

Edward Jenner, English physician and scientist who pioneered smallpox vaccine.

Penn Jillette magician, half of Penn & Teller duo. Co-creator and co-host of the television series Bullshit!

Teller, magician, other half of Penn & Teller duo. Co-creator and co-host of the television series Bullshit!

Barry Karr, Executive Director for the Committee for Skeptical Inquiry

Philip J. Klass, aerospace journalist. Known for his investigations of UFOs. Longstanding contributor to the Skeptical Inquirer. Founding member of CSICOP (now CSI).

Paul Kurtz, philosopher, author. Founder of CSICOP (now CSI), Publisher of the Skeptical Inquirer.

Michael Leunig, cartoonist.

Ash Lieb, artist, comedian and writer.

Scott Lilienfeld, professor of psychology, author, Consulting Editor for Skeptical Inquirer and Committee for Skeptical Inquiry Fellow

Pat Linse, illustrator. Cofounder of the Skeptics Society, Copublisher and Art Director of Skeptic magazine. Creator of Junior Skeptic magazine.

Daniel Loxton, illustrator, writer. Editor of Junior Skeptic magazine (bound into Skeptic magazine).

Tim Minchin, comedian, musician, actor. Has many songs illustrating his skepticism, most notably, Storm.

Rob Nanninga, writer and editor of Skepter.

Joe Nickell, investigator of the paranormal, author. Columnist for the Skeptical Inquirer.

Steven Novella, neurologist. Founder of the New England Skeptical Society and host of The Skeptics' Guide to the Universe podcast.

James Oberg, aerospace journalist. Critic of UFOs and claims of a moon landing hoax.

Robert L. Park, physicist, and author of Voodoo Science.

Massimo Pigliucci, professor of philosophy at City University of New York and co-host of the skeptical podcast, Rationally Speaking.

Steven Pinker, Canadian experimental psychologist, cognitive scientist, linguist, popular science author, Harvard College Professor and advocate of evolutionary psychology and the computational theory of mind.

Philip Plait, astronomer, author. Founder of the Bad Astronomy website.

Massimo Polidoro, writer, journalist. Student of James Randi, Co-Founder and Executive Director of CICAP, Research Fellow of CSICOP (now CSI).

Basava Premanand publisher of the Indian Skeptic magazine and chairman of the Indian CSICOP.

Benjamin Radford, Managing Editor of the Skeptical Inquirer, co-host of Squaring the Strange podcast.

James Randi, magician. Founder of the James Randi Educational Foundation. Notable for offering a million dollar cash reward for verifiable demonstration under laboratory conditions of any paranormal ability or event. Conceived and directed Project Alpha. Founding member of CSICOP (now CSI).

Pascual Romero, co-host of the Squaring the Strange podcast, providing evidence-based analysis and commentary on a variety of paranormal topics.

Emily Rosa, Guinness World Record youngest medical researcher; at age 11, published her study in the Journal of the American Medical Association on therapeutic touch, showing practitioners couldn't feel the "human energy field" when not looking.

Carl Sagan, astronomer, popular science author, and media personality. Advocate for SETI, founder of the Planetary Society, host of the TV series Cosmos and author of The Demon Haunted World: Science as a Candle in the Dark. Founding member of CSICOP (now CSI).

Cara Santa Maria, a science communicator, journalist, producer, television host, and podcaster. She currently is a co-host on The Skeptics' Guide to the Universe podcast, and hosts her own podcast Talk Nerdy.

Adam Savage, co-creator of the TV series MythBusters.

Eugenie Scott, anthropologist. Executive Director of the National Center for Science Education (NCSE), critic of creationism and intelligent design.

Robert Sheaffer, author. UFO investigator, columnist for the Skeptical Inquirer.

Michael Shermer, historian, popular science author, founder of the Skeptics Society. Copublisher and Editor of Skeptic magazine. Also current writer for the Scientific American column "Skeptic".

Simon Singh, popular British science author.

Julia Sweeney, actress, comedian, author and performer of Letting Go of God.

Jamy Ian Swiss, magician, co-founder of the National Capital Area Skeptics; co-founder of the New York City Skeptics; contributor to Skeptic magazine; co-producer and on-stage host of Northeast Conference on Science and Skepticism. on board of San Diego Association for Rational Inquiry (aka San Diego Skeptics).

Marcello Truzzi, sociologist. First editor of the Skeptical Inquirer. Critic of organized skepticism. Founding member of CSICOP (now CSI).

Rebecca Watson, founder of Skepchick blog.

Richard Wiseman, psychologist.

Paul Zenon, magician and comedian.

Moral skepticism

Moral skepticism (or moral scepticism) is a class of metaethical theories all members of which entail that no one has any moral knowledge. Many moral skeptics also make the stronger, modal claim that moral knowledge is impossible. Moral skepticism is particularly opposed to moral realism: the view that there are knowable and objective moral truths.

Some defenders of moral skepticism include Pyrrho, Aenesidemus, Sextus Empiricus, David Hume, J. L. Mackie (1977), Max Stirner, Friedrich Nietzsche, Richard Joyce (2001), Michael Ruse, Joshua Greene, Richard Garner, Walter Sinnott-Armstrong (2006b), and the psychologist James Flynn. Strictly speaking, Gilbert Harman (1975) argues in favor of a kind of moral relativism, not moral skepticism. However, he has influenced some contemporary moral skeptics.

Philosophical skepticism

Philosophical skepticism (UK spelling: scepticism; from Greek σκέψις skepsis, "inquiry") is a philosophical school of thought that questions the possibility of certainty in knowledge. Skeptic philosophers from different historical periods adopted different principles and arguments, but their ideology can be generalized as either (1) the denial of possibility of all knowledge or (2) the suspension of judgement due to the inadequacy of evidence.


Platonism, rendered as a proper noun, is the philosophy of Plato or the name of other philosophical systems considered closely derived from it. In narrower usage, platonism, rendered as a common noun, refers to the philosophy that affirms the existence of abstract objects, which are asserted to "exist" in a "third realm" distinct both from the sensible external world and from the internal world of consciousness, and is the opposite of nominalism. Lower case "platonists" need not accept any of the doctrines of Plato.In a narrower sense, the term might indicate the doctrine of Platonic realism. The central concept of Platonism, a distinction essential to the Theory of Forms, is the distinction between the reality which is perceptible but unintelligible, and the reality which is imperceptible but intelligible. The forms are typically described in dialogues such as the Phaedo, Symposium and Republic as transcendent perfect archetypes of which objects in the everyday world are imperfect copies.

In the Republic the highest form is identified as the Form of the Good, the source of all other forms, which could be known by reason. In the Sophist, a later work, the forms being, sameness and difference are listed among the primordial "Great Kinds". In the 3rd century BC, Arcesilaus adopted skepticism, which became a central tenet of the school until 90 BC when Antiochus added Stoic elements, rejected skepticism, and began a period known as Middle Platonism.

In the 3rd century AD, Plotinus added mystical elements, establishing Neoplatonism, in which the summit of existence was the One or the Good, the source of all things; in virtue and meditation the soul had the power to elevate itself to attain union with the One. Platonism had a profound effect on Western thought, and many Platonic notions were adopted by the Christian church which understood Plato's forms as God's thoughts, while Neoplatonism became a major influence on Christian mysticism, in the West through St Augustine, Doctor of the Catholic Church whose Christian writings were heavily influenced by Plotinus' Enneads, and in turn were foundations for the whole of Western Christian thought.

Problem of induction

The problem of induction is the philosophical question of whether inductive reasoning leads to knowledge understood in the classic philosophical sense, highlighting the apparent lack of justification for:

Generalizing about the properties of a class of objects based on some number of observations of particular instances of that class (e.g., the inference that "all swans we have seen are white, and, therefore, all swans are white", before the discovery of black swans) or

Presupposing that a sequence of events in the future will occur as it always has in the past (e.g., that the laws of physics will hold as they have always been observed to hold). Hume called this the principle of uniformity of nature.The problem calls into question all empirical claims made in everyday life or through the scientific method, and, for that reason, the philosopher C. D. Broad said that "induction is the glory of science and the scandal of philosophy." Although the problem arguably dates back to the Pyrrhonism of ancient philosophy, as well as the Carvaka school of Indian philosophy, David Hume popularized it in the mid-18th century.

Prometheus Books

Prometheus Books is a publishing company founded in August 1969 by the philosopher Paul Kurtz (who was also the founder of the Council for Secular Humanism, Center for Inquiry, and co-founder of the Committee for Skeptical Inquiry). Prometheus Books publishes a range of books, focusing on topics such as science, freethought, secularism, humanism, and skepticism. Their headquarters is located in Amherst, New York, and they publish worldwide. The publisher's name was derived from Prometheus, the Titan from Greek mythology who stole fire from Zeus and gave it to man. This act is often used as a metaphor for bringing knowledge or enlightenment.

Authors published by Prometheus include Steve Allen, Molefi Asante, Isaac Asimov, Jeremy Bentham, Rob Boston, Ludwig Feuerbach, Antony Flew, R. Barri Flowers, Martin Gardner, Guy P. Harrison, Sidney Hook, Julian Huxley, S. T. Joshi, Dr. Jack Kevorkian, John Maynard Keynes, Philip J. Klass, Leon Lederman, John W. Loftus, Joe Nickell, Friedrich Nietzsche, Mario Perniola, Robert M. Price, James Randi, David Ricardo, Nathan Salmon, George H. Smith, John Steinbeck IV, Victor Stenger, Tom Toles and Ibn Warraq.

Prometheus Books obtained the bulk of the books and manuscripts of Humanities Press International. It has been building and expanding this into a scholarly imprint named Humanity Books. This imprint publishes academic works across a wide spectrum of the humanities.

In 1992 Uri Geller sued Victor J. Stenger and Prometheus Books for libel. The suit was dismissed and Geller was required to pay more than $20,000 in costs to the defendant.In March 2005, Prometheus Books launched the science fiction and fantasy imprint Pyr. In October 2012 it launched the crime fiction imprint Seventh Street Books.

As of 2006, the company and its various imprints have approximately 1,600 books in print and publish approximately 95–100 books per year. Since its founding, Prometheus Books has published more than 2,500 books.

In 2013 Prometheus Books partnered with Random House in an effort to increase sales and distribution.


Pseudoskepticism (or pseudoscepticism) is a philosophical or scientific position which appears to be that of skepticism or scientific skepticism but which in reality fails to be so.


Pyrrhonism was a school of skepticism founded by Pyrrho in the fourth century BC. It is best known through the surviving works of Sextus Empiricus, writing in the late second century or early third century AD.

Religious skepticism

Religious skepticism is a type of skepticism relating to religion. Religious skeptics question religious authority and are not necessarily anti-religious but skeptical of specific or all religious beliefs and/or practices. Socrates was one of the most prominent and first religious skeptics of whom there are records; he questioned the legitimacy of the beliefs of his time in the existence of the Greek gods. Religious skepticism is not the same as atheism or agnosticism and some religious skeptics are deists.

Skeptical Inquirer

Skeptical Inquirer is a bimonthly American general-audience magazine published by the Committee for Skeptical Inquiry (CSI) with the subtitle: The Magazine for Science and Reason. In 2016 it celebrated its fortieth anniversary. For most of its existence, the Skeptical Inquirer (SI) was published by the Committee for the Scientific Investigation of Claims of the Paranormal, widely known by its acronym CSICOP. In 2006 the CSICOP Executive Council shortened CSICOP's name to the Committee for Skeptical Inquiry (CSI) and broadened its mission statement.

Skeptical movement

The skeptical movement (British spelling: sceptical movement) is a modern social movement based on the idea of scientific skepticism (also called rational skepticism). Scientific skepticism involves the application of skeptical philosophy, critical-thinking skills, and knowledge of science and its methods to empirical claims, while remaining agnostic or neutral to non-empirical claims (except those that directly impact the practice of science). The movement has the goal of investigating claims made on fringe topics and determining whether they are supported by empirical research and are reproducible, as part of a methodological norm pursuing "the extension of certified knowledge". The process followed is sometimes referred to as skeptical inquiry.Roots of the movement date at least from the 19th century, when people started publicly raising questions regarding the unquestioned acceptance of claims about spiritism, of various widely-held superstitions, and of pseudoscience.

Publications such as those of the Dutch Vereniging tegen de Kwakzalverij (1881) also targeted medical quackery.

Using as a template the Belgian organization founded in 1949, Comité Para, Americans Paul Kurtz and Marcello Truzzi founded the Committee for the Scientific Investigation of Claims of the Paranormal (CSICOP), in Amherst, New York in 1976. Now known as the Committee for Skeptical Inquiry (CSI), this organization has inspired others to form similar groups worldwide.

The Skeptic's Dictionary

The Skeptic's Dictionary is a collection of cross-referenced skeptical essays by Robert Todd Carroll, published on his website and in a printed book. The site was launched in 1994 and the book was published in 2003 with nearly 400 entries. As of January 2011 the website has over 700 entries. A comprehensive single-volume guides to skeptical information on pseudoscientific, paranormal, and occult topics, the bibliography contains some seven hundred references for more detailed information. According to the back cover of the book, the on-line version receives approximately 500,000 hits per month.

The Skeptic's Dictionary is, according to its foreword, intended to be a small counterbalance to the voluminous occult and paranormal literature; not to present a balanced view of occult subjects.

The Skeptics Society

The Skeptics Society is a nonprofit, member-supported organization devoted to promoting scientific skepticism and resisting the spread of pseudoscience, superstition, and irrational beliefs. The Skeptics Society was founded by Michael Shermer as a Los Angeles-area skeptical group to replace the defunct Southern California Skeptics. After the success of its magazine, Skeptic, introduced in early 1992, it became a national and then international organization. The stated mission of Skeptics Society and Skeptic magazine "is the investigation of science and pseudoscience controversies, and the promotion of critical thinking."

The Straight Dope

"The Straight Dope" was a question-and-answer newspaper column written by Cecil Adams and illustrated by Slug Signorino, first published in 1973 in the Chicago Reader as well as syndicated nationally in the United States.Following the column of June 27, 2018, "Straight Dope" was placed on hiatus, with no decision made regarding its future.

This page is based on a Wikipedia article written by authors (here).
Text is available under the CC BY-SA 3.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.