Two small victories for free speech in Europe yesterday. First, Holocaust denier David Irving won an appeal against the severity of his sentence in Austria, and will be allowed to return to Britain today.

Irving was arrested just over a year ago and sentenced to three years jail for “denying the existence of gas chambers at Auschwitz” (he now says he was “mistaken”). His conviction was upheld on appeal, but yesterday the court suspended the last two years of his sentence.

In the other case, Turkish publisher Fatih Tas, together with a translator and two editors, was acquitted on a charge of insulting “Turkishness”, under the controversial article 301 of Turkey’s penal code. They had attracted attention for publishing a translation of Noam Chomsky’s book Manufacturing Consent, which in passing criticises Turkey’s treatment of its Kurds.

Both cases show that the attempt to suppress opinion by force has a habit of being counter-productive.

Irving’s release comes a week too late for him to participate in Iranian president Ahmadinejad’s conference of Holocaust “revisionists”, at which he would have been a principal speaker. But from his point of view, that’s a small sacrifice to make for the publicity that his “martyrdom” has attracted.

Those who support the sort of laws under which Irving was jailed should ask themselves which has done more harm to the credibility of Holocaust deniers – locking one up in Austria, or letting a whole collection of them make fools of themselves in Tehran?

Chomsky’s work is not at the same level of offensive looniness as Irving’s, but some of it is not far off (although not, as it happens, the parts to which Turkish nationalists objected). The dangers of having legislators decide where the academic “mainstream” lies, however, should be obvious.

The appropriate response to offensive speech is argument, or ridicule, or even silence – but not laws.