Howard Jacobson: Designer babies could put us on a slippery slope to producing more Victoria Beckhams

Wouldn't it be nice if she could have a child genetically equipped to recognise a book?

Since this cannot be what we mean by a "designer" baby, what are we so afraid is going to happen if we allow expectant parents to specify a few alterations? We are, says Tony Calland, chairman of the Welsh Council of the British Medical Association and member of the BMA's ethics committee, on a "slippery slope".

To what? To breeding children who don't say we are on a slippery slope? A generation born without the capacity to speak in clichés - would that be so terrible? Or delivered into the world, unlike Victoria Beckham, with the reading gene? Wouldn't it be nice if she could have one genetically equipped to recognise a book - even if it's only the book that mummy wrote?

I see the problem. What if Victoria wants to ensure that no future child of hers is born with an advantage she does not herself possess? What if her dream is of a family that does everything together, including not reading? Does the state have any right to interfere?

Yes. Where design actually means undesign, where the parents wish to program in a deficiency - as did the deaf couple who had made such a virtue of their disability that they wanted to confer it on their baby - then yes, we must view it as we would the infliction of a cruelty on a child already born. Never mind that we have so engineered the language that every handicap must now be spoken of as though it is an adornment; what we have done to words we must not do to children.

For the most part, though, designing down does not seem to be anyone's fear. What appears to haunt Tony Calland's imagination is not a new humanity bred on purpose to be puny, but the prospect of a manufactured master race. "There are a lot of people," he has said, "who will see any loosening of this Act" - ie, the 1990 Fertility Act governing the dos and don'ts of IVF - "as a further step on the slippery slope - the end point being where you decide you want a blond-haired blue-eyed girl who is bright and good at tennis."

I take the blond-haired blue-eyed to be a backward nod at Aryan eugenics, though I'm not sure how the tennis fits into that. Steffi Graf maybe. But then if the "end point" - by which Tony Calland would seem to be implying a sort of ethical doomsday - is a nation of Steffi Grafs, shouldn't such an eventuality be welcomed?

The truth is, if you want your daughter to be a tennis player, you don't just hope: you make provision for her at an early age, pay for lessons, hire her a coach, send her to Florida. In what sense is that not an act of engineering? The only difference being that by doing it genetically you get in earlier than the Russians and save yourself some money.

There is democracy in designing your unborn baby. It will still cost you but not nearly so much as it will later. Thus does a whole new world of opportunity open for the poor. As for English tennis, it will assuredly improve once the middle classes in their effeteness no longer enjoy a monopoly of it.

When it comes to predetermining how our kids will look, we already do that by virtue of the choice of spouse we make. If I have a fancy for red-eyed and stocky I am likely to have picked a stocky red-eyed wife, just as she, if her fancy is for something similar, will have picked out me. What we love in our partners or ourselves is usually what we hope to perpetuate. A species of unconscious gene selection in which I find absolutely nothing sinister.

Should we, however, for one reason or another, prefer a change in the family physiognomy or build, then our lack of vanity should be applauded. We admire people who improve their personal circumstances, refusing to accept that just because they were born a Spice Girl they must stay a Spice Girl; similarly we should offer encouragement to those who can no longer abide their appearance and aspire to do better, aesthetically, by their offspring.

Had my own parents been in a position, say, to elongate their children genetically, I hope they would have embraced the opportunity. It was only Darwinian adaptation that had made us the shape we were anyway - shortish and broadish being a better build for people scratching a living in the marshlands of the Volga basin than rangy and easily unbalanced.

Why, if the process can be speeded up, do we have to wait another 500 years for our bodies to notice we are back on dry land? It is the purest heredity conservatism - the biological equivalent of the rich man at his castle and the poor man at his gate - to revere genetic inequity because it has always been with us.

The playing at God argument isn't worth a candle. We play at God every time we save a life. And if we are indeed endowed with free will, then we may legitimately decide we are better at being God than God is. You messed up. You sent us into this breathing world deformed, unfinished, scarce half made up, now step aside and allow us to do better.

Unless the doubters are too sanguine. What is it Tony Calland fears again - our opting for blond hair, blue eyes, bright and good at tennis? What's "bright" doing in that list? Who values brightness any more? My own fear is that what we mean by a designer baby is Victoria Beckham after all.