Deborah Orr: When liberals go on the attack, why do they always sound so intolerant?

the US once more becomes engulfed in the "culture wars" and prepares to boil down the world, the universe and everything to whether you agree with abortion or not, Britain really ought now to be consoling itself. At least things are not quite so black and white for us.

But instead, we are rehearsing our own teensy culture war, and going absolutely bonkers because Professor Michael Reiss, the director of education at the Royal Society, has suggested that it would not be a bad idea if science teachers acknowledged in the classroom that their pupils might be being told contrary narratives at home. His view is sensible, even bland, but you'd think he'd called for Darwin's head on a platter.

The annoying thing about fundamentalism is that it tends to polarise its opponents, and sometimes makes them look every bit as unable to engage or listen or reason as the people who prefer to cling to absolutes. A science teacher who cannot dismiss creationism in a few crisp sentences, or find the generosity of spirit to at least let conflicted pupils ask some questions about it, is not much of an ambassador for his subject.

A desire to avoid the dangers of polarisation is part of the explanation of why Barack Obama seems so floored by Sarah Palin. Many of his supporters have fallen for the easy option, and fled to the certainties offered by a blind liberalism that is actually as dogmatic as anything the Republicans have to offer.

This forces Obama into a similar position. If he is at all conciliatory, he risks alienating his strident base, for whom there can be no compromise – or so they think anyway. But it should not be that way. Liberal democracy needs its certainties too, and if liberalism has failed, as many Americans fervently believe it has, then it is because it does not even try any more to define and defend the bottom line.

Often, a genuinely liberal view simply emerges, as a result of the tensions between opposing sides. The abortion debate is a good example of this. Many women insist that they despise Palin because of her views on abortion. Yet while I don't agree with them, I don't find that they cannot be understood. Palin, like a vast number of people, believes that human life begins at conception. Such a belief dictates that abortion is murder, whatever the circumstances of a conception, and whatever the life-chances of a foetus.

I can't identify with those who consider such a position to be incomprehensible or repulsive. In fact, I understand how distressing and disturbing abortion must seem to people who think this way. And I don't believe it is a useful strategy, politically, to dismiss such a view as entirely lacking in intellect or morality. Insisting that pro-life views have no credence at all is just as reductive as suggesting that only science can ever be discussed in a science class.

The adoption of the epithet "pro-life", even those most ardently opposed to the position acknowledge, is a powerful coupling of words. It suggests that if you oppose this view, you are pro-death. Although the phrase "pro-choice" has been hammered home as the real alternative to such a position, it is not even understood any more as an accurate description of the nuanced attitude most supporters of abortion take.

We do believe in choice, but this choice has its logical limits. We believe that a human life begins when a baby is capable of living and breathing independently of its mother, even with some help. That's why there are always time limits involved in abortion legislation, and why it is important that impartial scientists are always involved in decisions about where that point should reasonably lie.

Certainly, liberals should understand a pro-life position to be perfectly valid, as long as the favour is returned. After all, without choice, there is no freedom and no democracy. It is sad that in America, positions that offer no freedom of choice at all are being challenged with such shrill and unsympathetic ineffectuality. It is sadder still that it is done in the name of liberalism.

Nicole's face is her fortune

Nicole Kidman has been revealed as the film star who offers her employers the least value for money. The Australian Oscar winner topped a Forbes poll of the actors who delivered the smallest profit at the box office, in comparison with the fees they command. She might not see it, but this is a good thing.

Lots of actresses fall into the trap that she has. Kidman, the fool, wants to be taken seriously, yet her head seems to have been turned by the notion that she's the prettiest girl in the world as well. Much of the hard work she does, in promoting her films, has the effect of promoting the idea of herself as a commodity instead. This sparks endless interest from the celebrity magazines, which in turn makes her life all the more strange and rarified. It's a velvet rut.

Presently, the studios pay a premium on actors willing to hawk themselves thus, in the belief that general interest and high exposure puts bottoms on cinema seats. Actually, it doesn't. It merely turns decent actors into mannequins so out of touch that they can't even tell a decent movie from a turkey any more. Kidman used to be considered a major talent, and proved early in her career that she wasn't just a pretty face. Now, the pretty face is all that's left.

Cookery lessons to take with a pinch of salt

Does this government ever learn? If there is a soul in Britain still defending its top-down approach to the management of our lives, then it is a lonely soul. Yet even something as simple as putting together a 32-page cook-book for schools has been launched as a major Whitehall initiative, with recipes suggested by members of the public (social democracy in action!) being distributed to every child in the land. Centrally distributed politically-correct spag bol. Has food ever sounded less appetising?

Actually, gathering recipes is something that schools can – and sometimes do – organise themselves. If the idea is to get parents involved, then a simple letter to the head of each school suggesting that this might be something to think about, is surely as much nudging as needs to be indulged in.

It is of course a good idea for children to learn to cook. But a parent previously impervious to this notion is unlikely suddenly to snap to attention when another bit of official bumf arrives. Anyone who doesn't know the basics of nutrition – or parenting – nowadays, is resistant to the imprecations of the printed word. That's why all those government messages so rarely hit the "hard to reach".

* At last Joe Biden has made his presence felt as Obama's pick for vice president. He has declared that Hillary Clinton might have been a better choice, and suddenly the world is listening. Like Alistair Darling with his economic woes and Obama himself with guns and God, to name only the very recent offenders, poor old Biden has learned that a gaffe occurs when a politician accidentally blurts out the truth.