Denialism

Denialism is choosing to deny reality as a way to avoid an uncomfortable truth: "[it] is the refusal to accept an empirically verifiable reality. It is an essentially irrational action that withholds validation of a historical experience or event". In science, denialism has been defined as the rejection of basic concepts that are undisputed and well-supported parts of the scientific consensus on a topic in favor of ideas that are both radical and controversial.

It has been proposed that the various forms of denialism have the common feature of the rejection of overwhelming evidence and the generation of a controversy through attempts to deny that a consensus exists. The terms Holocaust denialism and AIDS denialism have been used,    and the term climate change denialists has been applied to those who refuse to accept that climate change is occurring. Several motivations for denial have been proposed, including religious beliefs and self-interest, or as a psychological defense mechanism against disturbing ideas.

The broad use of the word denialism is controversial, as it has been criticized as a polemical method of suppressing non-mainstream views. Similarly, in an essay discussing the general importance of skepticism, Clive James objected to the use of the word denialist to describe climate change skeptics, stating that it "calls up the spectacle of a fanatic denying the Holocaust". Celia Farber has objected to the term AIDS denialists arguing that it is unjustifiable to place this belief on the same moral level with the Nazi crimes against humanity. However, Robert Gallo et al. defended this comparison, stating that AIDS denialism is similar to Holocaust denial as it is a form of pseudoscience that "contradicts an immense body of research".

Orthodoxy and heterodoxy
Anthropologist Didier Fassin distinguishes between denial, defined as "the empirical observation that reality and truth are being denied", and denialism, which he defines as "an ideological position whereby one systematically reacts by refusing reality and truth".

Individuals or groups who reject propositions on which a scientific or scholarly consensus exists can engage in denialism when they use rhetorical tactics to give the appearance of argument or legitimate debate, when in actuality there is none. Indeed, Seth Kalichman summarizes the "several incarnations of denialism" by stating: "All denialism is defined by rhetorical tactics designed to give the impression of a legitimate debate among experts when in fact there is none".

In a newspaper article in 2003 Edwin Cameron, a senior South African judge and an AIDS sufferer, described the tactics used by those who deny the Holocaust and those who deny that the AIDS pandemic is predominantly due to infection with the HIV virus. He states that "For denialists, the facts are unacceptable. They engage in radical controversion, for ideological purposes, of facts that, by and large, are accepted by almost all experts and lay persons as having been established on the basis of overwhelming evidence". To do this they employ "distortions, half-truths, misrepresentation of their opponents' positions and expedient shifts of premises and logic."

Mark Hoofnagle has described denialism as "the employment of rhetorical tactics to give the appearance of argument or legitimate debate, when in actuality there is none." It is a process that operates by employing one or more of the following five tactics in order to maintain the appearance of legitimate controversy:
 * 1) Conspiracy theories — Suggesting opponents have an ulterior motive for their position or are part of a conspiracy.
 * 2) Cherry picking — Selecting an anomalous critical paper supporting their idea, or using outdated, flawed, and discredited papers in order to make their opponents look like they base their ideas on weak research.
 * 3) False experts — Paying an expert in the field, or another field, to lend supporting evidence or credibility.
 * 4) Moving the goalpost — Dismissing evidence presented in response to a specific claim by continually demanding some other (often greater) piece of evidence. In other words, after an attempt has been made to score a goal, the goalposts are moved to exclude the attempt. Thus denialists use the absence of complete and absolute knowledge to prevent the implementation of sound policies, or the acceptance of an idea or theory.
 * 5) Other logical fallacies — Usually one or more of false analogy, appeal to consequences, straw man, or red herring.

Tara Smith of the University of Iowa also stated that moving goalposts, conspiracy theories and cherry-picking evidence are general characteristics of denialist arguments, but went on to note that these groups spend "majority of their efforts critiquing the mainstream theory" in an apparent belief that if they manage to discredit the mainstream view, their own "unproven ideas will fill the void".

Edwin Cameron notes that a common tactic used by denialists is to "make great play of the inescapable indeterminacy of figures and statistics", as scientific studies of many areas rely on probability analysis of sets of data, and in historical studies the precise numbers of victims and other facts may not be available in the primary sources. Such "recourse to data debates and pseudo-scientific 'evidence'" has also been noted as a common feature of several types of denialism in a 2009 article published in the journal Globalization and Health. This is an area which British historian Richard J. Evans mentioned as part of his analysis of the David Irving's work which he presented for the defence when Irving sued Deborah Lipstadt for libel: Reputable and professional historians do not suppress parts of quotations from documents that go against their own case, but take them into account, and, if necessary, amend their own case, accordingly. They do not present, as genuine, documents which they know to be forged just because these forgeries happen to back up what they are saying. They do not invent ingenious, but implausible, and utterly unsupported reasons for distrusting genuine documents, because these documents run counter to their arguments; again, they amend their arguments, if this is the case, or, indeed, abandon them altogether. They do not consciously attribute their own conclusions to books and other sources, which, in fact, on closer inspection, actually say the opposite. They do not eagerly seek out the highest possible figures in a series of statistics, independently of their reliability, or otherwise, simply because they want, for whatever reason, to maximize the figure in question, but rather, they assess all the available figures, as impartially as possible, in order to arrive at a number that will withstand the critical scrutiny of others. They do not knowingly mistranslate sources in foreign languages in order to make them more serviceable to themselves. They do not wilfully invent words, phrases, quotations, incidents and events, for which there is no historical evidence, in order to make their arguments more plausible.

Prescriptive and polemic
If one party to a debate accuses the other of denialism they are framing the debate, because denialism is prescriptive: it carries implications that there is a truth that the other side denies, and polemic because the accuser usually goes on to explain how the other party is denying the asserted truth and as such the other party is in the wrong, which leads to an implied accusation that if the accused party persist with the denial despite the evidence their motives must be false.

Edward Skidelsky, a lecturer in philosophy at Exeter University, has suggested that this is a new use for the word denial and it may have its origins in an old sense of "deny", akin to "disown", (as in the Apostle Peter denying Christ), but that its more immediate antecedence is from the Freudian sense of deny as a refusal to accept a painful or humiliating truth, and that it from this form of denial the abstract noun "denialism", has recently been coined. He writes that "An accusation of 'denial[ism]' is serious, suggesting either deliberate dishonesty or self-deception. The thing being denied is, by implication, so obviously true that the denier must be driven by perversity, malice or wilful blindness." He suggests that by introducing the use of denialism to more and more areas of historical and scientific debate that "One of the great achievements of the Enlightenment—the liberation of historical and scientific enquiry from dogma—is quietly being reversed" and that this should worry liberal-minded people.

AIDS denialism
AIDS denialism is the denial that the human immunodeficiency virus (HIV) is the cause of acquired immune deficiency syndrome (AIDS). AIDS denialism has been described as being "among the most vocal anti-science denial movements". Some denialists reject the existence of HIV, while others accept that the virus exists but say that it is a harmless passenger virus and not the cause of AIDS. Insofar as denialists acknowledge AIDS as a real disease, they attribute it to some combination of recreational drug use, malnutrition, poor sanitation, and side effects of antiretroviral medication, rather than infection with HIV. However, the evidence that HIV causes AIDS is scientifically conclusive and the scientific community rejects and ignores AIDS-denialist claims as based on faulty reasoning, cherry picking, and misrepresentation of mainly outdated scientific data. With the rejection of these arguments by the scientific community, AIDS-denialist material is now spread mainly through the Internet.

Corporate denialism
International corporations such as ExxonMobil have been criticized for contributing to scientists and scientific experimentation questioning the scientific consensus on global climate change. ExxonMobil did not deny making the financial contributions, but its spokesman stated that the company's financial support for scientific reports did not mean it influenced the outcome of those studies. "The recycling of this type of discredited conspiracy theory diverts attention from the real challenge at hand: how to provide the energy needed to improve global living standards while also reducing greenhouse gas emissions." Newsweek and Mother Jones have published articles stating corporations are funding the "denial industry".

In the context of consumer protection, denialism has been defined as "the use of rhetorical techniques and predictable tactics to erect barriers to debate and consideration of any type of reform, regardless of the facts."

Holocaust denialism
The term has been used with "Holocaust denialism" as "the refusal to accept an empirically verifiable reality. It is an essentially irrational action that withholds validation of a historical experience or event."

Political denialism
The Bush Administration's replacement of previous science advisers with industry experts or scientists tied to industry, and its refusal to submit the Kyoto Protocol for ratification due to uncertainties they asserted were present in the climate change issue, have been cited as examples of politically motivated denialism by the press. The general class of genocide denial, of which holocaust denial is a subset, is another form of political denialism.