Claire Fox: Debate is being stifled by a new form of inquisition

What do has-been "comedian" Jim Davidson, DNA pioneer Professor James Watson, TV nature man David Bellamy and Tory MP Patrick Mercer have in common? They have all been recently denounced and told – You can't say that or else!

Whether or not unpalatable views have been expressed, these views fade into insignificance beside the relentless clampdown on those who go against the grain.

The real danger is that we are entering a new era of the heresy and heretic hunting – whether it's ITV bosses booting out some middle-aged has-been from a reality TV show for his homophobic row about shirt-lifters, or Bellamy's own admission this week that he's been branded a heretic for his unfashionably sceptical views on man-made climate change. Not only have certain issues become taboo in a way that touches the totalitarian, we demonise those who don't conform.

This is more than a case of the hackneyed complaint against political correctness gone mad. I fear that we are engaged in modern-day witch hunts. Western societies seem to have become prey to powerful illiberal and intolerant influences and have rediscovered the charge of heresy as a means of silencing those who question prevailing cultural orthodoxies. Healthy heresy – described in more enlightened times as critical thinking, sceptical enquiry, or even free speech – is again being hunted down. That is why no subject should be treated as a taboo.

Is heresy too strong a term? Of course, today the old Inquisition stands discredited and the Catholic Church holds little sway in dictating what we can say or think. However the American academic, Professor Arthur Versluis usefully reminds us in his important book The New Inquisitions of the connections between heretic hunting in medieval times and totalitarian trends today.

A new priestly class has arisen to police secular heresies. Say the wrong thing on race and watch the CRE swoop zealously to demand you retract, are sacked, are humiliated. Their viciousness and intolerance would make medieval cardinals blush. Dare you challenge global warming orthodoxy, and watch everyone from the Royal Society to environmentalists shout "blasphemy"? James Watson may not have been shown the instruments of torture as Galileo was but his treatment speaks to some chilling similarities between the new and old inquisitions.

Take 19-year-old drama-school brat Emily Barr being dragged from her bed to the Big Brother diary room at 3.30am, confused and groggy, while the disembodied voice of Channel 4 authority condemned her for using an "unacceptable word" ("nigger") while she pleaded hysterically that she was not racist. She was then asked to leave the house in only a night-gown, and holed up in a hotel before being placed in the hands of a psychologist – the modern equivalent of the stocks. As we watch young Emily, Professor Watson and Jim Davidson drummed out of respectable society and recant, we know we are all being told to be careful what we say, and who we offend. We are encouraged by every telling-off to become more and more obedient and super-cautious lest we too are humiliated.

One of the key weapons of the new inquisitions is the notion of denial. The label of "denial" – applied with ever-greater promiscuity – expresses the illiberal notion that contentious issues are beyond debate. It is the most pungent and effective tool in shutting up those who challenge today's received wisdom. It began with Holocaust denial. Few of us would want to get into an argument with an actual Holocaust denier – why argue with lunatic theories? But the criminalisation of Holocaust denial has led to the repression of other denials of conventional wisdom. To be accused of denial is to be outcast.

The notion of Holocaust denial, now raised to the status of secular blasphemy, has beenrevised and adopted for themodern era.

The European Union has recently moved to outlaw genocide denial; this means anyone convicted of denying the genocide of the Jews in Europe before and during the Second World War, or the mass killings in Bosnia and Rwanda, will face a prison term ranging from one to three years. The French National Assembly passed a law in October last year that could sentence to a year's imprisonment anyone who denies the Armenian genocide.

Other "thought crimes" – whilst not against the law – also invoke the pernicious denial label, most obviously the accusation of "climate-change denial" attributed to anyone who does not wholeheartedly embrace global warming orthodoxies.

So what do you do if you have serious doubts about the received wisdom, but you know that your ideas will be denounced as heresy? If we stigmatise those who question "self-evident" truths, how will interrogativedebate survive?

Surely this can only breed a conformist outlook, forcing open debate on to the back foot. Free thinkers cannot help but question the prevailing dogma, which often involves a denial of the official version of the truth. We are entitled to argue and debate and freely express our views about everything. And in our conformist era, a healthy dose of heresy is no bad thing.

Claire Fox is Director of the Institute of Ideas; Prof Arthur Versluis is speaking at the The Battle of Ideas, which takes place at the Royal College of Art, Kensington Gore, London SW7 2EU this weekend; www.battleofideas.org.uk