Sagan standard

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Carl Sagan, seen here with a model of Viking lander, popularized the standard. Sagan large.jpg
Carl Sagan, seen here with a model of Viking lander, popularized the standard.

The Sagan standard is the aphorism that "extraordinary claims require extraordinary evidence" (sometimes shortened to ECREE). [1] It is named for science communicator Carl Sagan, who used the phrase in his 1979 book Broca's Brain and the 1980 television program Cosmos . The standard has been described as fundamental to the scientific method and is regarded as encapsulating the basic principles of scientific skepticism.

Contents

The Sagan standard is similar to Occam's razor in that both heuristics prefer simpler explanations of a phenomenon to more complicated ones. In application, there is some ambiguity regarding when evidence is deemed sufficiently "extraordinary". The Sagan standard is often invoked to challenge data and scientific findings, or to criticize pseudoscientific claims. Some critics have argued that the standard can suppress innovation and affirm confirmation biases.

Similar statements were previously made by figures such as Thomas Jefferson in 1808, Pierre-Simon Laplace in 1814, and Théodore Flournoy in 1899. The formulation "Extraordinary claims require extraordinary proof" was used a year prior to Sagan, by scientific skeptic Marcello Truzzi. It has also been argued that philosopher David Hume first fully characterized the principles of the Sagan standard in his 1748 essay "Of Miracles".

Application

An interesting debate has gone on within the [ Federal Communications Commission ] between those who think that all doctrines that smell of pseudoscience should be combated and those who believe that each issue should be judged on its own merits, but that the burden of proof should fall squarely on those who make the proposals. I find myself very much in the latter camp. I believe that the extraordinary should certainly be pursued. But extraordinary claims require extraordinary evidence.

— Carl Sagan in his 1979 book Broca's Brain [2]

The Sagan standard—"Extraordinary claims require extraordinary evidence"—according to psychologist Patrizio Tressoldi, "is at the heart of the scientific method, and a model for critical thinking, rational thought and skepticism everywhere". [3] [4] [5] It has also been described as a "fundamental principle of scientific skepticism". [6] The phrase is often used in the context of paranormal and other pseudoscientific claims. [7] [8] [9] It is also frequently invoked in scientific literature to challenge research proposals, [10] like a new species of Amazonian tapir, [6] biparental inheritance of mitochondrial DNA, [11] or a Holocene "mega-tsunami". [12]

The standard is related to Occam's razor as, according to such a heuristic, simpler explanations are preferred to more complicated ones. Only in situations where extraordinary evidence exists would an extraordinary claim be the simplest explanation. [7] A routinized form of this appears in hypothesis testing where the hypothesis that there is no evidence for the proposed phenomenon, what is known as the "null hypothesis", is preferred. The formal argument involves assigning a stronger Bayesian prior to the acceptance of the null hypothesis as opposed to its rejection. [13]

Analysis and criticism

Science communicator Carl Sagan did not describe any concrete or quantitative parameters as to what constitutes "extraordinary evidence", which raises the issue of whether the standard can be applied objectively. [5] [14] [15] Academic David Deming notes that it would be "impossible to base all rational thought and scientific methodology on an aphorism whose meaning is entirely subjective". He instead argues that "extraordinary evidence" should be regarded as a sufficient amount of evidence rather than evidence deemed of extraordinary quality. [16] Tressoldi noted that the threshold of evidence is typically decided through consensus. This problem is less apparent in clinical medicine and psychology where statistical results can establish the strength of evidence. [5]

Deming also noted that the standard can "suppress innovation and maintain orthodoxy". [16] Others, like Etzel Cardeña, have noted that many scientific discoveries that spurred paradigm shifts were initially deemed "extraordinary" and likely would not have been so widely accepted if extraordinary evidence were required. [17] [18] Uniform rejection of extraordinary claims could affirm confirmation biases in subfields. [18] Additionally, there are concerns that, when inconsistently applied, the standard exacerbates racial and gender biases. [19] Psychologist Richard Shiffrin has argued that the standard should not be used to bar research from publication but to ascertain what is the best explanation for a phenomenon. [20] Conversely, mathematical psychologist Eric-Jan Wagenmakers stated that extraordinary claims are often false and their publication "pollutes the literature". [21] To qualify the publication of such claims, psychologist Suyog Chandramouli has suggested the inclusion of peer reviewers' opinions on their plausibility or an attached curation of post-publication peer evaluations. [18]

Cognitive scientist and AI researcher Ben Goertzel believes that the phrase is utilized as a "rhetorical meme" without critical thought. Philosopher Theodore Schick argued that "extraordinary claims do not require extraordinary evidence" if they provide the most adequate explanation. [9] Moreover, theists and Christian apologists like William Lane Craig have argued that it is unfair to apply the standard to religious miracles as other improbable claims are often accepted based on limited testimonial evidence, such as an individual claiming that they won the lottery. [22] [23]

Origin and precursors

Philosopher David Hume may have been the first to fully describe the principles of the Sagan standard. Allan Ramsay - David Hume, 1711 - 1776. Historian and philosopher - Google Art Project.jpg
Philosopher David Hume may have been the first to fully describe the principles of the Sagan standard.

Sagan popularized the aphorism in his 1979 book Broca's Brain , [2] [14] and in his 1980 television show Cosmos in reference to claims about extraterrestrials visiting Earth. [24] Sagan had first stated the standard in a 1977 interview with The Washington Post . [25] However, scientific skeptic Marcello Truzzi used the formulation "Extraordinary claims require extraordinary proof" in an article published by Parapsychology Review in 1975, [25] as well as in a Zetetic Scholar article in 1978. [26] Two 1978 articles quoted physicist Philip Abelson—then the editor of the journal Science —using the same phrasing as Truzzi. [27] [28]

In his 1748 essay "Of Miracles", philosopher David Hume wrote that if "the fact ... partakes of the extraordinary and the marvellous ... the evidence ... received a diminution, greater or less, in proportion as the fact is more or less unusual". [29] Deming concluded that this was the first complete elucidation of the standard. Unlike Sagan, Hume defined the nature of "extraordinary": he wrote that it was a large magnitude of evidence. [29] [30]

Others had also put forward very similar ideas. Quote Investigator cites similar statements from Benjamin Bayly (in 1708), Arthur Ashley Sykes (1740), Beilby Porteus (1800), Elihu Palmer (1804), and William Craig Brownlee (1824). [25] The French scholar Pierre-Simon Laplace, in essays (1810 and 1814) on the stability of the Solar System, wrote that "the weight of evidence for an extraordinary claim must be proportioned to its strangeness". [5] [25] Thomas Jefferson in an 1808 letter expresses contemporary skepticism of meteorites thus: "A thousand phenomena present themselves daily which we cannot explain, but where facts are suggested, bearing no analogy with the laws of nature as yet known to us, their verity needs proofs proportioned to their difficulty." [31] [32]

See also

Related Research Articles

<span class="mw-page-title-main">Carl Sagan</span> American astrophysicist, cosmologist and author (1934–1996)

Carl Edward Sagan was an American astronomer and science communicator. His best known scientific contribution is his research on the possibility of extraterrestrial life, including experimental demonstration of the production of amino acids from basic chemicals by exposure to light. He assembled the first physical messages sent into space, the Pioneer plaque and the Voyager Golden Record, which were universal messages that could potentially be understood by any extraterrestrial intelligence that might find them. He argued in favor of the hypothesis, which has since been accepted, that the high surface temperatures of Venus are the result of the greenhouse effect.

<span class="mw-page-title-main">Pseudoscience</span> Unscientific claims wrongly presented as scientific

Pseudoscience consists of statements, beliefs, or practices that claim to be both scientific and factual but are incompatible with the scientific method. Pseudoscience is often characterized by contradictory, exaggerated or unfalsifiable claims; reliance on confirmation bias rather than rigorous attempts at refutation; lack of openness to evaluation by other experts; absence of systematic practices when developing hypotheses; and continued adherence long after the pseudoscientific hypotheses have been experimentally discredited. It is not the same as junk science.

<span class="mw-page-title-main">Parapsychology</span> Study of paranormal and psychic phenomena

Parapsychology is the study of alleged psychic phenomena and other paranormal claims, for example, those related to near-death experiences, synchronicity, apparitional experiences, etc. Criticized as being a pseudoscience, the majority of mainstream scientists reject it. Parapsychology has also been criticised by mainstream critics for claims by many of its practitioners that their studies are plausible despite a lack of convincing evidence after more than a century of research for the existence of any psychic phenomena.

<span class="mw-page-title-main">Telepathy</span> Psychic ability

Telepathy is the purported vicarious transmission of information from one person's mind to another's without using any known human sensory channels or physical interaction. The term was first coined in 1882 by the classical scholar Frederic W. H. Myers, a founder of the Society for Psychical Research (SPR), and has remained more popular than the earlier expression thought-transference.

<span class="mw-page-title-main">Broca's area</span> Speech production region in the dominant hemisphere of the hominid brain

Broca's area, or the Broca area, is a region in the frontal lobe of the dominant hemisphere, usually the left, of the brain with functions linked to speech production.

<span class="mw-page-title-main">Lynn Margulis</span> American evolutionary biologist (1938–2011)

Lynn Margulis was an American evolutionary biologist, and was the primary modern proponent for the significance of symbiosis in evolution. Historian Jan Sapp has said that "Lynn Margulis's name is as synonymous with symbiosis as Charles Darwin's is with evolution." In particular, Margulis transformed and fundamentally framed current understanding of the evolution of cells with nuclei – an event Ernst Mayr called "perhaps the most important and dramatic event in the history of life" – by proposing it to have been the result of symbiotic mergers of bacteria. In 2002, Discover magazine recognized Margulis as one of the 50 most important women in science.

<span class="mw-page-title-main">Committee for Skeptical Inquiry</span> Organization examining paranormal claims

The Committee for Skeptical Inquiry (CSI), formerly known as the Committee for the Scientific Investigation of Claims of the Paranormal (CSICOP), is a program within the U.S. non-profit organization Center for Inquiry (CFI), which seeks to "promote scientific inquiry, critical investigation, and the use of reason in examining controversial and extraordinary claims." Paul Kurtz proposed the establishment of CSICOP in 1976 as an independent non-profit organization, to counter what he regarded as an uncritical acceptance of, and support for, paranormal claims by both the media and society in general. Its philosophical position is one of scientific skepticism. CSI's fellows have included notable scientists, Nobel laureates, philosophers, psychologists, educators, and authors. It is headquartered in Amherst, New York.

Paranormal events are purported phenomena described in popular culture, folk, and other non-scientific bodies of knowledge, whose existence within these contexts is described as being beyond the scope of normal scientific understanding. Notable paranormal beliefs include those that pertain to extrasensory perception, spiritualism and the pseudosciences of ghost hunting, cryptozoology, and ufology.

<span class="mw-page-title-main">Scientific skepticism</span> Questioning of claims lacking empirical evidence

Scientific skepticism or rational skepticism, sometimes referred to as skeptical inquiry, is a position in which one questions the veracity of claims lacking empirical evidence. In practice, the term most commonly refers to the examination of claims and theories that appear to be beyond mainstream science, rather than the routine discussions and challenges among scientists. Scientific skepticism differs from philosophical skepticism, which questions humans' ability to claim any knowledge about the nature of the world and how they perceive it, and the similar but distinct methodological skepticism, which is a systematic process of being skeptical about the truth of one's beliefs.

<span class="mw-page-title-main">HIV/AIDS denialism</span> False belief that HIV does not cause AIDS

HIV/AIDS denialism is the belief, despite conclusive evidence to the contrary, that the human immunodeficiency virus (HIV) does not cause acquired immune deficiency syndrome (AIDS). Some of its proponents reject the existence of HIV, while others accept that HIV exists but argue that it is a harmless passenger virus and not the cause of AIDS. Insofar as they acknowledge AIDS as a real disease, they attribute it to some combination of sexual behavior, recreational drugs, malnutrition, poor sanitation, haemophilia, or the effects of the medications used to treat HIV infection (antiretrovirals).

<span class="mw-page-title-main">Philip Abelson</span> American physicist and scientific editor (1913–2004)

Philip Hauge Abelson was an American physicist, scientific editor and science writer. Trained as a nuclear physicist, he co-discovered the element neptunium, worked on isotope separation in the Manhattan Project, and wrote the first study of nuclear marine propulsion for submarines. He later worked on a broad range of scientific topics and related public policy, including organic geochemistry, paleobiology and energy policy.

Pseudoskepticism is a philosophical or scientific position that appears to be that of skepticism or scientific skepticism but in reality is a form of dogmatism.

<span class="mw-page-title-main">Marcello Truzzi</span> American sociologist (1935–2003)

Marcello Truzzi was an American sociologist and academic who was professor of sociology at New College of Florida and later at Eastern Michigan University, founding co-chairman of the Committee for the Scientific Investigation of Claims of the Paranormal (CSICOP), a founder of the Society for Scientific Exploration, and director for the Center for Scientific Anomalies Research.

Evidence of absence is evidence of any kind that suggests something is missing or that it does not exist. What counts as evidence of absence has been a subject of debate between scientists and philosophers. It is often distinguished from absence of evidence.

<span class="mw-page-title-main">Telekinesis</span> Influencing of objects without physical interaction

Telekinesis is a hypothetical psychic ability allowing an individual to influence a physical system without physical interaction. Experiments to prove the existence of telekinesis have historically been criticized for lack of proper controls and repeatability. There is no reliable evidence that telekinesis is a real phenomenon, and the topic is generally regarded as pseudoscience.

In philosophy, a razor is a principle or rule of thumb that allows one to eliminate unlikely explanations for a phenomenon, or avoid unnecessary actions.

The Centre for Inquiry Canada (CFIC) is a not-for-profit educational organization with headquarters in Ottawa, Ontario, Canada. The Canadian organization was founded as a member and volunteer driven organization in 2007. It is the Canadian affiliate of CFI Transnational. Their primary mission is to provide education and training to the public in the application of skeptical, secular, rational and humanistic inquiry through conferences, symposia, lectures, published works and the maintenance of a library.

Hitchens's razor is an epistemological razor that serves as a general rule for rejecting certain knowledge claims. It states "what can be asserted without evidence can also be dismissed without evidence." The razor was created by and later named after author and journalist Christopher Hitchens (1949–2011). It implies that the burden of proof regarding the truthfulness of a claim lies with the one who makes the claim; if this burden is not met, then the claim is unfounded, and its opponents need not argue further in order to dismiss it. Hitchens used this phrase specifically in the context of refuting religious belief.

References

Citations

  1. ↑ Kaufman (2012), p. 124.
  2. 1 2 Sagan (1979), p. 62.
  3. ↑ Kiely et al. (2019), p. 1475.
  4. ↑ Lineweaver (2022)
  5. 1 2 3 4 Tressoldi, p. 1.
  6. 1 2 Voss et al. (2014), p. 893.
  7. 1 2 Smith (2011)
  8. ↑ Tressoldi, pp. 1–3.
  9. 1 2 Evidence for Psi (2015), p. 292.
  10. ↑ McMahon (2020), p. 117.
  11. ↑ Salas et al. (2020)
  12. ↑ Pinter et al. (2008), pp. 37–38.
  13. ↑ Matthews (2010), p. 6.
  14. 1 2 Deming (2016), p. 1320.
  15. ↑ The Library of Congress.
  16. 1 2 Deming (2016), pp. 1319–1320.
  17. ↑ Cardeña (2018), p. 673.
  18. 1 2 3 Shiffrin et al. (2021), p. 266.
  19. ↑ Shiffrin et al. (2021), p. 272.
  20. ↑ Shiffrin et al. (2021), p. 265.
  21. ↑ Shiffrin et al. (2021), pp. 265–266.
  22. ↑ Larmer (2015), p. 125.
  23. ↑ Craig (2008) [1994], p. 273.
  24. ↑ Sagan (1980), 1:24 min.
  25. 1 2 3 4 Quote Investigator (2021)
  26. ↑ Truzzi (1978), p. 11.
  27. ↑ U.S. News & World Report (1978), pp. 41–42.
  28. ↑ Rao (1978), pp. 41–42.
  29. 1 2 Deming (2016), p. 1328.
  30. ↑ Pigliucci (2013), p. 500.
  31. ↑ Berkes (2008)
  32. ↑ "Letter to Daniel Salmon".

Works cited

Books

  • Craig, William Lane (2008) [1994]. Reasonable Faith: Christian Truth and Apologetics. Crossway. ISBN   9781433501159.
  • Goertzel, Ben; Goertzel, Joe (2015). "Skeptical Responses to Psi Research". In Broderick D.; Goertzel B. (eds.). Evidence for Psi: Thirteen Empirical Research Reports. McFarland. pp. 291–301. ISBN   9780786478286. OCLC   896344862.
  • Kaufman, Marc (2012). First Contact: Scientific Breakthroughs in the Hunt for Life Beyond Earth (Reprint ed.). Simon and Schuster. ISBN   9781439109014.
  • Larmer, Robert A. (2013). The Legitimacy of Miracle. Lexington Books. ISBN   9780739184219.
  • Matthews, Paul (2010). Sample Size Calculations: Practical Methods for Engineers and Scientists. Mathews Malnar and Bailey. ISBN   9780615324616. Archived from the original on September 2, 2023. Retrieved March 19, 2023.
  • McMahon, Sean (2020). "Do Extraordinary Claims Require Extraordinary Evidence?". In Smith K. C.; Mariscal C. (eds.). Social and Conceptual Issues in Astrobiology. Oxford University Press. pp. 117–129. ISBN   9780190915650. Archived from the original on October 28, 2023. Retrieved October 22, 2023.
  • Sagan, Carl (1979). Broca's Brain: The Romance of Science. Hodder and Stoughton. ISBN   9780394501697.
  • Smith, Jonathan C. (2011). Pseudoscience and Extraordinary Claims of the Paranormal: A Critical Thinker's Toolkit. John Wiley & Sons. ISBN   9781444358940. Archived from the original on October 28, 2023. Retrieved March 19, 2023.

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