Skepticism (British spelling: Scepticism) can mean:

  • Philosophical skepticism - a philosophical position in which people choose to critically examine whether the knowledge and perceptions that they have are actually true, and whether or not one can ever be said to have absolutely true knowledge; or
  • Scientific skepticism - a scientific, or practical, position in which one questions the veracity of claims, and seeks to prove or disprove them using the scientific method.

Philosophical skepticism

Philosophical skepticism originated in ancient Greek philosophy. One of its first proponents was Pyrrho of Elis (c. 360-275 B.C.), who traveled and studied as far as India, and propounded the adoption of 'practical' skepticism. Subsequently, in the 'New Academy' Arcesilaos (c. 315-241 B.C.) and Carneades (c. 213-129 B.C.) developed more theoretical perspectives, whereby conceptions of absolute truth and falsity were refuted. Carneades criticised the views of the Dogmatists, especially supporters of Stoicism, asserting that absolute certainty of knowledge is impossible. Sextus Empiricus (c. A.D. 200), the main authority for Greek skepticism, developed the position further, incorporating aspects of empiricism into the basis for asserting knowledge.

Greek skeptics criticised the Stoics, accusing them of dogmatism. For the skeptics, the logical mode of argument was untenable, as it relied on propositions which could not be said to be either true or false without relying on further propositions. This was the argument of infinite regress, whereby every proposition must rely on other propositions in order to maintain its validity. In addition, the skeptics argued that two propositions could not rely on each other, as this would create a circular argument (as p implies q and q implies p). For the skeptics logic was thus an inadequate measure of truth which could create as many problems as it claimed to have solved. Truth was not, however, necessarily unobtainable, but rather an idea which did not yet exist in a pure form. Although skepticism was accused of denying the possibility of truth, in actual fact it appears to have mainly been a critical school which merely claimed that logicians had not discovered truth.

Scientific skepticism

Scientific skepticism is related to, but not identical to, philosophical skepticism. Many scientists and doctors who are skeptical of claims of the paranormal are nonetheless not adherents of classical philosophical skepticism. When critics of controversial scientific or paranormal claims are said to be skeptical, this only refers to their taking a position of scientific skepticism.

The term skeptic is now usually used to refer to a person who takes a critical position in a given situation, usually by employing the principles of critical thinking and the scientific method (that is, scientific skepticism) to evaluate the validity of claims and practices. Skeptics view empirical evidence as important, as it provides possibly the best way to determine the validity of a claim.

While skepticism involves the use of the scientific method and of critical thinking, this does not mean that skeptics necessarily use these tools consistently or simply find that there is indeed evidence of their belief.

Skeptics are often confused with, or even denounced as, cynics. However, valid skeptical criticism (as opposed to arbitrary or subjective misgivings about an idea) strictly originates from an objective and methodological examination that is often agreed between skeptics themselves. Note too that cynicism is generally seen as a viewpoint that maintains an unnecessarily negative attitude toward human motives and sincerity. While the two positions are not mutually exclusive and skeptics may also be cynics, they each represent a fundamentally different statement about the nature of the world.

Many critics accuse scientific skeptics of being "closed-minded" or of inhibiting scientific progress. Such critics, however, are often pseudoscientists, paranormalists, and spiritualists, whose views are not adopted or supported by mainstream science. Carl Sagan, the skeptic and astrophysicist, stated that "one should keep his mind open, but not so open one's brain falls out'. On the other hand, people who deny the possibility of something simply because it hasn't been proven by the scientific method often can inhibit scientific progress. Indeed, some skeptics would accuse those who maintained the impossibility of something of a lack of skepticism, as this position would entail an assertion about the true nature of the subject.

A debunker is a skeptic who pursues dispelling false and unscientific claims. Famous debunkers include James Randi, Basava Premanand, Penn and Teller and Harry Houdini. Many debunkers become rather controversial because they have strong opinions and can be vocal about things that may offend people, such as religion and pseudosciences. They have often been confronted so many times with the same, already disproven pseudoscience and quackery that their patience for these matters seems very thin to persons who are confronted with it for the very first time.

Critics of debunkers state that their conclusions are filled with self-interest, and that they are crusaders and true believers with a need for certainty and stability. They (true believers) are readily identified by their cognitive distortions. (In the world of science, the term "cognitive distortion" is not a slur, but a psychological explanation).

In particular, many pseudoscientists are quick to attack skeptics and skepticism in general because of resistance to their fringe ideas and theories, which lack evidence and which the scientific establishment does not accept.

Skepticism as inertia

Rejection of new ideas is the norm in the field of science. New ideas and unusual inventions tend to face the strongest and most vociferous opposition. Such a cautious approach toward adopting new ideas means that some good ideas are dismissed, in order that unproven ideas not be too quickly accepted. Controversy is common among scientists when new hypotheses are first presented, until such time as reproducibility can ensure that experimental results can be repeated again and again according to the scientific method. As a consequence, numerous scientists throughout history have been called frauds by peers who were unwilling or unable to accept something that would require a change in their world view when their ideas were initially presented. Michael Faraday was called a charlatan by his contemporaries when he announced that he could generate an electric current merely by moving a magnet in a coil of wire.

In January 1905, more than a year after Wilbur and Orville Wright had flown their historic first flight at Kitty Hawk on December 17 1903, Scientific American magazine carried an article ridiculing 'alleged' flights that the Wrights claimed to have made. With somber authority, the magazine cited as its main reason for doubting the Wrights the fact that the American press had failed to cover the alleged flights. Others who joined in the skeptic outcry were the New York Herald, the US Army, and numerous American scientists. Only when President Theodore Roosevelt ordered public trials at Fort Myers in 1908 could the Wright brothers confirm their claim and compel even the most zealous skeptics to accept the reality of heavier-than-air flying machines. In actuality, the Wright brothers had been successfully flying their flying machines in public demonstrations for five years before that historic flight, beginning in December 1903.

Most revolutionary modern day inventions, such as the scanning tunneling microscope that was invented in 1981, are still being met with intense skepticism and even ridicule when they are first announced. As physicist Max Planck observed in his book, "The Philosophy of Physics" 1936, "An important scientific innovation rarely makes its way by gradually winning over and converting its opponents: it rarely happens that Saul becomes Paul. What does happen is that its opponents gradually die out and that the growing generation is familiarized with the idea from the beginning."

Similarly, Marcello Truzzi (formerly a sociology professor at Eastern Michigan University) argues that some self-described skeptics are misusing the term or even misrepresenting their position: "Since 'skepticism' properly refers to doubt rather than denial--nonbelief rather than belief--critics who take the negative rather than an agnostic position but still call themselves 'skeptics' are actually 'pseudo-skeptics' and have, I believed, gained a false advantage by usurping that label."


The most commonly quoted statement associated with skepticism states:

Extraordinary claims require extraordinary proof.

Yet another quote in reference to skepticism is... ...."A wise skepticism is the first attribute of a good critic"....

Organizations dedicated to skepticism

TV shows and documentaries based upon skepticism

External links

da:Skepticisme de:Skeptizismus et:Skeptitsism es:Escepticismo fr:Scepticisme it:Scetticismo nl:Scepticisme pl:Sceptycyzm pt:Ceticismo ru:Скептицизм sk:Skepticizmus fi:Skeptismi


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