Salman Rushdie: Do we have to fight the battle for the Enlightenment all over again?

Democracy is not a tea party. In the end, a fundamental decision has to be made: do we want to live in a free society or not?

I was in Washington just before the Iraq war began and was invited to speak to groups of senators of both parties. The most obvious distinction between the Democrats and the Republicans was that the Republicans used exclusively religious language. They discussed why they hadn't seen each other at a certain prayer meeting. One Senator said to me, in tones of genuine horror, that what he disliked most about Osama bin Laden was that he called America a Godless country. He said: "How can he call us Godless? We're incredibly God-fearing!"

I was in Washington just before the Iraq war began and was invited to speak to groups of senators of both parties. The most obvious distinction between the Democrats and the Republicans was that the Republicans used exclusively religious language. They discussed why they hadn't seen each other at a certain prayer meeting. One Senator said to me, in tones of genuine horror, that what he disliked most about Osama bin Laden was that he called America a Godless country. He said: "How can he call us Godless? We're incredibly God-fearing!"

I said: "Well, Senator, I suppose he doesn't think so." But his outrage at being presented as un-Godly was undeniably sincere. He meant business. And the increasing power of God-fearing America - of the Christian coalition, Mel Gibson variety - subsequently determined the result of last November's presidential election.

Now I come back to Britain and discover another kind of "anschluss" of liberal values in the face of resurgent religious demands. It seems we need to fight the battle for the Enlightenment all over again in Europe too.

That battle was about the church's desire to place limits on thought. The Enlightenment wasn't a battle against the state but against the church. Diderot's novel La Religieuse, with its portrayal of nuns and their behaviour, was deliberately blasphemous: it challenged religious authority, with its indexes and inquisitions, on what it was possible to say. Most of our contemporary ideas about freedom of speech and imagination come from the Enlightenment. We may have thought the battle won, but if we aren't careful, it is about to be "un-won".

Offence and insult are part of everyday life for everyone in Britain. All you have to do is open a daily paper and there's plenty to offend. Or you can walk into the religious books section of a bookshop and discover you're damned to various kinds of eternal hellfire, which is certainly insulting, not to say overheated.

The idea that any kind of free society can be constructed in which people will never be offended or insulted, have the right to call on the law to defend them against being offended or insulted, is absurd. In the end a fundamental decision needs to be made: do we want to live in a free society or not? Democracy is not a tea party where people sit around making polite conversation. In democracies people get extremely upset with each other. They argue vehemently against each other's positions. (But they don't shoot.)

At Cambridge I was taught a laudable method of argument: you never personalise, but you have absolutely no respect for people's opinions. You are never rude to the person, but you can be savagely rude about what the person thinks. That seems to me a crucial distinction: people must be protected from discrimination by virtue of their race, but you cannot ring-fence their ideas. The moment you say that any idea system is sacred, whether it's a belief system or a secular ideology, the moment you declare a set of ideas to be immune from criticism, satire, derision, or contempt, freedom of thought becomes impossible.

With their "incitement to religious hatred law", this government has set out to create that impossibility. Privately they'll tell you the law is designed to please "the Muslims". But which Muslims, when and on what day?

The ability of this law to protect "the Muslims" seems to me arguable. It is entirely possible that instead it will be used against Muslims before it's used against anyone else. There are identifiable racist and right-wing groups in this country who would argue that Muslims are the ones inciting religious hatred, and these groups will use, or try to use, this law.

There is no question that there also are Muslim leaders who are anxious to prosecute - for example - The Satanic Verses, and will try to do so if this law is passed. So this law will unleash some major expressions of intolerance.

Already rioting Sikhs have forced the closure of Gurpreet Kaur Bhatti's play, Behzti, in Birmingham and the government has said nothing to criticise what was effectively criminal action. Hanif Kureishi made one of the best comments about all this, when he noted that the theatre was a temple, too - just as much as the fictional temple in the play. Evangelical Christians caught on quickly and protested against the BBC's screening of Jerry Springer. The Opera.

I took issue with the Granta editor Ian Jack when he declared that he was perfectly happy for the British police to defend Wapping when print workers were striking, but not the Birmingham theatre from the offended Sikhs. Forgive me for not seeing the logic of the principle of "restraint" he invoked. It seems to me to be a liberal failure to say that even though we don't understand what is upsetting the offended, we shouldn't upset them. That's condescension. That's saying "you can have your little religion over there in the corner and we won't fool with you."

What this kind of attitude ultimately does, and what the Government's law will do, is to undermine a principle of free expression which affects everyone in this country, religious or not. If we cannot have open discourse about the ideas by which we live, then we are straitjacketing ourselves.

It does matter that people have the right to take an argument to the point where somebody is offended by what they say. It's no trick to support the free speech of somebody you agree with or to whose opinion you are indifferent. The defence of free speech begins at the point when people say something you can't stand. If you can't defend their right to say it, then you don't believe in free speech. You only believe in free speech as long as it doesn't get up your nose. But free speech does get up people's noses. Nietzche - as Matthew Parris recently reminded us - called Christianity "the one great curse" and "the one immortal blemish on mankind". Would Nietzsche now be prosecuted?

There is a long tradition of irreverent, raw, and critical remarks about religion in this country, some by very eminent thinkers, some by our favourite comedians - like Rowan Atkinson in Blackadder muttering "Bad weather is God's way of telling us we should burn more Catholics." Even if the Government doesn't think that such remarks will find their way into court prosecutions, the very possibility that they might, at the discretion of the Attorney General, will be enough to bring down the curtains of self- and corporate censorship.

It will be a sad day if this bad law comes into effect. If it does, we shall have to break it and have it tested in the courts which one hopes will recognise its manifest absurdity.

Salman Rushdie is President of American PEN, and a supporter of English PEN's Free Expression is No Offence campaign