Picture this. A Frenchwoman in her 60s and her brother in his 50s turn up at a Los Angeles fertility clinic and get treatment costing around $160,000 (£113,500). Brother's sperm impregnates a surrogate mother, who also passes an egg to sister, so that she can get pregnant too. When the babies are born, brother admits that his sperm - and not that of an anonymous donor - was used to fertilise his sister's borrowed egg. Brother is now the proud father of two. Sister has given birth to her brother's baby.

"My baby is not the result of incest," she says. "Yes, I am 62 and my brother is 52, but we are better suited to raising children than a couple of drug addicts who live on the fringes of society."

This pair live with their 80-year old mother, described as "spectacularly wealthy", though she's only worth a couple of million, hardly enough to keep her in vin blanc and fromage frais. The family are said to hate each other and the brother shot himself through the chin five years ago in a failed suicide attempt. Acquaintances fear that the children are an attempt to settle the inheritance question when maman hangs up her onions. Never mind, at least none of them takes drugs.

Maybe not, but their adventures have put the entire French nation on a tanker of Prozac. Blood pressure is at record levels, as moral outrage is fanned by the gaucheness of the act. Why had the pair never married? Why could he not find a mistress? Why hadn't she taken a lover, years ago, to do what men and women do so easily and sometimes well - make love and have children?

Making babies is not rocket science, though doctors would like us to think so. Hidden behind this case is the troubling question of IVF and science's increasing control over reproduction - read women. IVF is an invasive treatment with poor results. The woman's body is flooded with hormones, causing mood swings and depression. Early menopause is common. Women, like the rest of society, have swallowed the lie that we can have everything. It is our right to have everything. The price for women on IVF is health, self-esteem, and physical autonomy. Yes, sometimes it works, but as Germaine Greer has noted: "There are winners in every unjust situation."

In France IVF is illegal for post-menopausal women. Surely we could all agree on this? The counter-argument runs that men can father children any time, so why not women?

Nature knows better than science. Fathers come and go - if you will pardon the joke - and will absent themselves from parenting on any excuse, death being the most respectable. Mothers are here to stay. As such, motherhood is not a suitable retirement hobby.

Why did the doctor go ahead with the treatment? She claims she thought they were husband and wife. Does that make them morally competent? The woman is on a pension and the man is a suicide survivor. Wouldn't you have commissioned a psychological report? This is Los Angeles. Shrinks are as plentiful as out-of-work actors. Probably they are out-of-work actors.

Nevertheless, the doctor asked no questions, took the money, performed the op, and now we have a child whose father is also his uncle. Faust couldn't have arranged the bargain better.

Of course, everyone in this Rocky Horror Show family saga considers themselves blameless and morally upright. The sister assumes that because she didn't actually have sex with her brother, their relationship is not incestuous. Obviously she hasn't read The Duchess of Malfi. The doctor probably doesn't read anything except bank statements.

This is the problem. You don't develop a moral sense by watching television and making money. Old-fashioned though it may be, you need art and culture. The French are supposed to be good at that. But then they are supposed to be good at sex, too.

Science, which wants to have the answer to everything, has never learned the basic lesson of art - that human nature is what we're dealing with. We read books, go to plays, look at pictures, so that we can do more than serve our instincts. Civilisation depends on a subtle and complex code that is not the law. Self-regulation and personal responsibility are not easy virtues and we are not born to them. Religion tries to supply this want with obedience but art teaches us to be conscious.

In our own brave new world where science hypnotises us into belief, we need to be conscious. The Royal Society is debating a ban on human cloning. Doctors talk casually about test-tube birth becoming the norm. All of us should have a part in this. The age-old question "How shall I live?" is too urgent to be answered by science.