A free press is essential to a working democracy. Without a free exchange of information, debates about policy and exposure to different ideas, society becomes sclerotic and intolerant.

But the lesson that many journalists are taking from this awful day is that what democracies need is more blasphemy. "We must reaffirm the importance of absolute freedom of expression in an open society -- regardless of how offensive it might be to some and, on occasion, how puerile it may become," writes Bill Durodie in The Conversation. And Ross Douthat, of the New York Times, argues that blasphemy is an essential part of democracy. "When offenses are policed by murder, that's when we need more of them, not less, because the murderers cannot be allowed for a single moment to think that their strategy can succeed."

When Muslim terrorists try to muzzle the press, perhaps we do need to defend blasphemy, but with a clothes peg on our noses. It may be a democratic right to be offensive, but so is respecting your daughter's right to marry a convicted rapist or her right to live as an anorexic. Is it really the high point of Enlightenment values to defend Charlie Hebdo's right to publish cartoons of the Pope sodomising his priests? Surely democracy means more than this.

Islam has failed if these three killers found in it justification for the murder of innocent people. But secular France has also failed because it has failed to persuade these young men that democracy is about more than tasteless cartoons. Isn't about time that we stopped complaining about the evils of Islam and started extolling the transcendent dignity of man, Christianity's finest gift to Western culture?

This is the message of the writer featured on this week's cover of Charlie Hebdo. We don't know yet whether Michel Houellebecq's novel Soumission (Submission) had anything to do with the killings, but it has something to offend everyone, especially Muslims. Houellebecq is France's most prominent and most controversial novelist at the moment. His latest work is a political fantasy which takes place in 2022 when a charismatic Muslim is elected President of France. Immediately women start wearing the veil, the Qur'an is made compulsory at university and polygamy is legalised.

No doubt right-wing voters will interpret the novel as an apocalyptic warning about the triumph of the Caliphate. But Houellebecq, in a fascinating interview, frames it as a critique of the Enlightenment. After two centuries, he says, the defining ideology of the French state has failed.

Enlightenment values have become stale and religion is resurgent. People cannot live without God. Houellebecq himself, who once called Islam "the stupidest of all religions" appears to have regained some of his Christian faith. "Look, the Enlightenment is dead," he says. "May it rest in peace. ... In itself, it can produce nothing, just emptiness and unhappiness. So yes, I am hostile to Enlightenment philosophy, I need to make that perfectly clear."

In the short run, this spate of terrorist attacks needs to be crushed with vigorous police and intelligence work. But in the long run, France and other Western societies need to promote an attractive, dynamic, humane philosophy which responds to our unquenchable thirst for transcendent values. Why not return to Christianity?

Michael Cook is editor of MercatorNet