When an editor at the Washington Post heard that I oppose laws criminalising Holocaust and, by extension, genocide denial, he observed: ‘Now that’s a “man bites dog” story.’

His surprise is shared by many people who hear my view. These folks expect that, given the six-year legal battle to which British historian David Irving subjected me for calling him a Holocaust denier, I would be a strong proponent for such laws. The legal battle was exceptionally costly and it seriously disrupted my life.

Irving and his fellow deniers are liars and falsifiers of truth when it comes to the Holocaust and even to other aspects of history – for example, the bombing of Dresden. This alone makes some people think his outrageous claims should be outlawed.

Regarding Irving, who seems to me to love to say the outrageous, and his version of so-called history, the judge who presided over our legal battle – Judge Charles Gray – was unambiguous. In his judgment he used the following terms: ‘perverts’, ‘distorts’, ‘misleading’, ‘unjustified’, ‘travesty’, and ‘unreal’, and said his ‘falsification of the historical record was deliberate’.

So why not silence Irving and his compatriots? First of all, I believe in free speech. In the United States, the First Amendment guarantees people a right to make total fools of themselves. Sometimes it is painful to hear, but I would rather they had the freedom to say what they wished than the government had the power to control them.

Furthermore, I do not believe that laws against denial are strategically wise. They tend to make martyrs of the accused, arousing sympathy for them. They also render the item which has been outlawed ‘forbidden fruit’. Thus it becomes more enticing and appealing to certain segments of society – disaffected youth, for example.

Most importantly, however, genocide denial laws suggest that we do not have the facts and the documentation to prove that these people are liars. We defeated David Irving in court not with law but with facts. We followed his footnotes and demonstrated that, in the words of Professor Richard Evans, Irving’s work on the Holocaust was a ‘tissue of lies’.

Our defeat of Irving is a far more powerful commentary on his work because it is rooted in the facts and did not occur under the cover of a general law outlawing Holocaust denial. I was, of course, quite lucky in that I had a magnificent legal team and group of historical experts.

The effort was long and quite costly. (Though certainly not as costly as David Irving likes to claim it was. I recently spotted an estimate of six million dollars on his webpage. Notice, of course, his choice of number. This is complete fiction and his form of ridicule.) I was able to mount a vigorous defence. Irving’s reputation as a person with something of value to say about the Holocaust was left in tatters.

Ironically, none of this would have happened had the UK had laws outlawing Holocaust denial.

I shudder at the thought that politicians might be given the power to legislate history. They can hardly fix the potholes in our streets. How can we expect them to decide what is the proper version of history?

Let me add two caveats. I believe quite strongly that those who engage in incitement – which is often the object of denial – and lead others to engage in acts of violence should not be granted a shield of protection by the law. Some people throw stones. Others use words to encourage people to throw stones. Both are equally guilty.

Secondly, I fully understand why countries such as Germany and Austria, the countries which spawned the Holocaust, would have laws against Holocaust denial. The geographic context in which something is said is of crucial importance. The swastika or denial of the Holocaust has a different resonance in Atlanta than it does in Berlin or Vienna.

I know this may be inconsistent, but I am reminded of what the American essayist and poet Ralph Waldo Emerson wrote many years ago: ‘A foolish consistency is the hobgoblin of little minds, adored by little statesmen and philosophers and divines.’

I write this from Sarajevo. Today, a professor, who happens to be a Serb, told me that she believes laws against genocide denial are necessary in this region: denying the horrors that took place here in the mid-1990s should be illegal, at least for the near future. She argued that this is a region in which the ‘rule of law’ has never been imposed justly, fairly, and democratically. A law outlawing denial of the genocide and crimes against humanity which occurred in this region would give people that faith and prevent them from trying to find other ways of seeking justice.

I don’t agree with these positions; however, I recognise that I say these things in the luxury of my American university or, as I will on Monday evening, in the confines of London’s Institute of Contemporary Arts. It can be different when one has an ‘up close and personal’ perspective on these outrages.

Ultimately, our objective should be to create a society where denial of genocide is seen as so outrageous and so despicable that anyone who engages in it would be rendered a pariah.

Deborah E Lipstadt is Dorot Professor at Emory University and the author of History on Trial: My Day in Court with David Irving, published by Ecco 2005.

She is speaking in the debate Should Genocide Denial Be An Offence? at the Institute of Contemporary Arts in central London at 7pm this evening (Monday, 16 July). Other speakers include David Cesarani, research professor in history at Royal Holloway College, University of London, and author of Eichmann: His Life and Crimes; Frank Furedi, professor of sociology at the University of Kent and author of Politics of Fear: Beyond Left and Right; and Francesca Klug, professorial research fellow at the Centre for the Study of Human Rights, LSE, and author of Values for a Godless Age. For more information, click here.