Tomorrow, I'll be taking part in a debate in Edinburgh about whether creationism and its pseudo-scientific counterpart, intelligent design (ID), should be taught in schools. What interests me more than the question itself, however, is why it is even being asked. Because isn't the answer obvious? Yes, it should, but not as science.

It's easy to foam at the mouth about how funda-mentalists want Genesis rammed down the throats of our kids and Darwin ripped out of textbooks and burned - but actually, hardly anyone is trying to do this. Secularists and mainstream religious leaders agree that Adam and Eve no more belong in biology textbooks than Noah does in manuals of animal husbandry. Among British education leaders at least, dissenters are a minority who may be intelligent in other respects but clearly have cerebral pockets of pottiness. The only serious question is whether creationism should be discussed in schools at all, and I'm baffled as to why so many think the only respectable answer is "no".

Last year, for example, Michael Reiss was forced to resign as director of education at the Royal Society for saying little more than that dismissing pupils who had creationist views as simply being wrong was "counter-productive".

"I realised that simply banging on about evolution and natural selection didn't lead some pupils to change their minds at all," he said. "Now I would be more content simply for them to understand it as one way of understanding the universe."

Reiss clearly stated he did not consider either creationism or intelligent design to be scientific theories. However, he suggested there was "much to be said for allowing students to raise any doubts they have", and that this was "hardly a revolutionary idea in science teaching." It's not an obviously batty or anti-scientific one, either.

Indeed, there are very good schools where this is already the case. In England and Wales, some sixth-formers study "perspectives on science", a fascinating course that looks at the philosophy, ethics, sociology and history of science. As part of this, they examine the relation between science and religion in a measured, intelligent way. I wish all schoolchildren had the same opportunity.

So it seems clear to me that creationism and ID should not be taught as science, but should be covered in schools, perhaps even in some form of science studies. It seems baffling that this should be so contentious that Reiss had to resign for saying more or less the same thing.

If you look at the wider picture, however, it seems to fit a pattern of disproportionate and selective outrage at religion. We had the community nurse who was suspended for foolishly offering to pray for a patient. We had Rowan Williams, the Archbishop of Canterbury, ridiculed for his comments about Sharia law, which were actually very modest and probably quite sensible. We had resistance to the "incitement to religious hatred" law, which, although in many ways justified, exaggerated the threat to free speech it presented. In each case strong disagreement was not enough, and righteous indignation took over.

These cases seem even odder when you consider that many schools routinely say prayers and sing hymns, and have done for years; that bishops are given seats in the House of Lords; and that our national anthem implores God to save the Queen. It's as though society has put bouncers on its doors, refusing entry to anyone carrying offensive weapons like crucifixes or Bibles, when half the people already inside are dressed in cassocks.

Religion and secular society have become like oil and water, when for decades they have co-existed in a murky, messy sludge. And oil that floats on water can burn. That's why I don't want it to be a taboo to discuss creationism in schools, and religion in secular society.

The best way to defend science, evolution and reason against the young-earthers and their ilk is for sensible believers and non-believers alike to make sure that vigorous demolition of literalist nonsense is carried out in the open, and is not confused with the demonisation of religious belief. If we fight the wrong battles, the war will be more violent than it need be. And it will never be won. Julian Baggini will be taking part in the debate Should Schools Teach Creationism? at the National Library of Scotland, Edinburgh, tomorrow, 6.30pm. For information, call 0131 623 4675.