New Scientist: Living in denial: Questioning science isn't blasphemy.
THE epithet "denier" is increasingly used to bash anyone who dares to question orthodoxy. Among other things, deniers are accused of subordinating science to ideology. In his book Denialism: How irrational thinking hinders scientific progress, harms the planet, and threatens our lives, for example, Michael Specter argues that denialists "replace the rigorous and open-minded scepticism of science with the inflexible certainty of ideological commitment".
How ironic. The concept of denialism is itself inflexible, ideological and intrinsically anti-scientific. It is used to close down legitimate debate by insinuating moral deficiency in those expressing dissident views, or by drawing a parallel between popular pseudoscience movements and the racist extremists who dispute the Nazi genocide of Jews.
As philosopher Edward Skidelsky of the University of Exeter, UK, has argued, crying denialism is a form of ad hominem argument: "the aim is not so much to refute your opponent as to discredit his motives". The expanding deployment of the concept, he argues, threatens to reverse one of the great achievements of the Enlightenment - "the liberation of historical and scientific inquiry from dogma".
Don't get me wrong: the popular appeal of pseudoscience is undoubtedly a problem. But name-calling is neither a legitimate nor an effective response.
Take, for example, two areas in which I have had some involvement: the controversies arising from Peter Duesberg's claim that HIV does not cause AIDS, and the links between vaccines and autism alleged by the former academic gastroenterologist Andrew Wakefield.
Both Duesberg and Wakefield were reputable scientists whose persistence with hypotheses they were unable to substantiate took them beyond the limits of serious science. Though they failed to persuade their scientific peers, both readily attracted supporters, including disaffected scientists, credulous journalists, charlatans, quacks and assorted conspiracy theorists and opportunist politicians.
In both cases, scientists were dilatory in responding, dismissing the movements as cranks and often appearing to believe that if they were ignored they would quietly disappear. It took five years before mainstream AIDS scientists produced a comprehensive rebuttal of Duesberg. Though child health authorities were alert to the threat of the anti-vaccine campaign, researchers were slow to respond, allowing it to gather momentum.
Social psychologist Seth Kalichman of the University of Connecticut in Storrs mounts a typical defence of this stance in his book Denying Aids: Conspiracy theories, pseudoscience, and human tragedy. According to Kalichman, denialists often "cross the line between what could arguably be protected free speech". He justifies suppression of debate on the feeble grounds that this would only legitimise the deniers and that scientists' time would be better spent on research.
Such attempts to combat pseudoscience by branding it a secular form of blasphemy are illiberal and intolerant. They are also ineffective, tending not only to reinforce cynicism about science but also to promote a distrust for scientific and medical authority that provides a rallying point for pseudoscience.
As Skidelsky says, "the extension of the 'denier' tag to group after group is a development that should alarm all liberal-minded people". What we need is more debate, not less.