懐疑論と否定論の識別 by Steven Novella(2002)

懐疑論と否定論は別物であるが、Steven Novella(2002)によれば、「科学と疑似科学を一貫して区別することが困難である」のと同様にグレーゾーンがある。
The Demarcation Problem

Philosophers of science often speak of the demarcation problem, referring to the difficulty of distinguishing consistently between science and pseudoscience. I am proposing that there are two subsets to this demarcation problem, between appropriately skeptical science and true belief or gullibility at one end, and absolute denial at the other. Both extremes represent pseudoscience, in the former case the process of science is distorted to affirm a desired conclusion, and in the latter it is distorted in order to deny an undesired conclusion. At both ends healthy scientific skepticism blends imperceptibly into pseudoscience, with no sharp demarcation, hence the problem.


At both extremes, gullibility and denial, the core of pseudoscience is the same – namely that pseudoscientists begin with a desired conclusion, and then go through the superficial motions of science to arrive at their predetermined conclusion. Whereas with healthy science inquiry precedes belief or condemnation. For deniers, their dedication to the denial of the offensive belief supercedes fair-minded skepticism. While attempting to portray themselves as skeptics, they are forced to employ a series of pseudoscientific tactics and logical fallacies to maintain their denial.


With a fuzzy border between skepticism and denial, how do we tell the difference? Adding to the difficulty, individuals or groups may combine legitimate skeptical arguments with denial strategies. What is necessary is to identify specific strategies that represent denial and distinguish them from the strategies of good skepticism.

懐疑論と否定論の間のファジーな境界で、両者の違いをどう見分ければいいだろうか? 困難であることに加えて、個人あるいはグループは、正当な懐疑的議論と否定論戦略を組み合わせる。必要なことは、否定論を代表する特定戦略の識別と、良き懐疑論の戦略の区別である

There are many examples of deniers we can use for this purpose. The two most prominent deniers faced by skeptics are those who deny the reality of the Jewish holocaust, and those who deny that evolution is an established scientific fact. Both holocaust deniers and evolution deniers have their own literature, filled with sophisticated arguments to support their denials.


[ Steven Novella, MD: "Skepticism and Denial" (2002/04) ]

  • Argument from Final Consequences (最終結論からの論)
  • Selective use of Evidence(証拠の選択的使用)
  • Argument by Definition(定義による論)
  • Moving Goalposts(ゴールポストの移動)
  • Confusing Internal Debate over Details with Negation of the Whole(内部詳細の論争と、全体の否定の混同)
  • Correlation is not Causation(相関は因果ではない)
  • Emerging Skepticism(懐疑論の出現)


Michael Shermerも同様の「懐疑論者」と「否定論者」の線引きを提示している。

WHAT is the difference between a sceptic and a denier? When I call myself a sceptic, I mean that I take a scientific approach to the evaluation of claims. A climate sceptic, for example, examines specific claims one by one, carefully considers the evidence for each, and is willing to follow the facts wherever they lead.

A climate denier has a position staked out in advance, and sorts through the data employing "confirmation bias" - the tendency to look for and find confirmatory evidence for pre-existing beliefs and ignore or dismiss the rest.

Scepticism is integral to the scientific process, because most claims turn out to be false. Weeding out the few kernels of wheat from the large pile of chaff requires extensive observation, careful experimentation and cautious inference. Science is scepticism and good scientists are sceptical.

Denial is different. It is the automatic gainsaying of a claim regardless of the evidence for it - sometimes even in the teeth of evidence. Denialism is typically driven by ideology or religious belief, where the commitment to the belief takes precedence over the evidence. Belief comes first, reasons for belief follow, and those reasons are winnowed to ensure that the belief survives intact.

Denial is today most often associated with climate science, but it is also encountered elsewhere. For example, there are those who do not believe that HIV causes AIDS. Others say that the Holocaust did not happen, or reject the overwhelming evidence for evolution. All merit the moniker "denier", because no matter how much evidence is laid out before them they continue to deny the claim.






[ Michael Shermer: "Living in denial: When a sceptic isn't a sceptic" (2010/05/18) on NewScientist ]

Though the distinction between scepticism and denial is clear enough in principle, keeping them apart in the real world can be tricky. It has, for example, become fashionable in some circles for anyone who dares to challenge the climate science "consensus" to be tarred as a denier and heaved into a vat of feathers. Do you believe in global warming? Answer with anything but an unequivocal yes and you risk being written off as a climate denier, in the same bag as Holocaust and evolution naysayers.

Yet casting questions like these as a matter of belief is nonsensical. Either the Earth is getting warmer or it is not, regardless of how many believe it is or is not. When I say "I believe in evolution" or "I believe in the big bang", this is something different from when I say, "I believe in a flat tax" or "I believe in liberal democracy".

Either evolution and the big bang happened or they did not; both matters can, in principle, be solved with more data and better theory. But the right form of taxation or government cannot be answered with more data and better theory. They are ideological positions that are established by subjective debate. Liberals committed to one vision of society will marshal evidence to support their political beliefs, while conservatives buttress their own world view. Both sides are sceptical of each other's position, both deny information that contradicts their own views, and in most cases disputes are resolved not through experiment and hypothesis testing but through democratic election.

What sometimes happens is that people confuse these two types of questions - scientific and ideological. Sometimes the confusion is deliberate. Denial is one outcome. Thus, one practical way to distinguish between a sceptic and a denier is the extent to which they are willing to update their positions in response to new information. Sceptics change their minds. Deniers just keep on denying.





[ Michael Shermer: "Living in denial: When a sceptic isn't a sceptic" (2010/05/18) on NewScientist ]
地球温暖化や進化論についての見方は、宗教や政党支持と絡んでおり、「人は科学の問題とイデオロギーの問題を混同」しやすい。そして「 否定論者は否定し続ける。」そして、おそらく否定論者自身は自らを懐疑論者だと考えていて、それを覆すことはできないだろう。