The scientists can clone a human being, but they cannot clone its soul

In genetics, as in nuclear physics, scientific developments may have outstripped mankind's ability to control them

A cloned human embryo has been an experiment waiting to happen. Even if it turned out that Dr Panos Zavos's claims were exaggerated, this would merely postpone the inevitable confrontation with ethical dilemmas. Sooner rather than later, the techniques will be perfected and used.

The recent advances in the genome project and genetic medicine have not yet been widely understood. But they are revolutionary. Within a few decades, scientists will understand every detail of the human body's cellular structure. When necessary, they will be able to modify it. This should eliminate all diseases caused by cellular disorders, thus increasing life expectancy by up to 50 per cent.

People would be advised to have a thorough genetic-based medical while still in their twenties. The doctors would then be able to predict when the first set of vital organs would wear out, and there would be plenty of time to grow cloned replacements.

Between the age of 50 and 70, midlife pit-stop surgery would become routine, in order to replace the old organs. Once that had happened, the beneficiaries should live to 120 or 130 - which is only an upper limit because the body would run out of skin cells. Who knows; the genetic engineers may also find a remedy for that. By 2100, the frontiers of future life expectancy could be advancing towards an unknown upper limit.

Though all this may sound exciting, it will cause immense difficulties. It is hard to think through the implications for the age-population structure and the working lifetime, but they will be profound. Longevity might also lead to gerontocracy. Moreover, the new medicine will almost certainly be so expensive that it would not be universally affordable.

Any medical gap between rich and poor could widen enormously, as would the disparity between the advanced world and the rest. By the middle of the century, access to the genetic revolution may well be a major political issue. It will certainly be a major ethical concern. During all these advances, the hidden mysteries of life itself will be exposed to scrutiny. This will not only enable doctors to cure the living. They will also be able to create life, for it will prove impossible to police the frontiers between genetic modification and full-scale cloning.

There is one obvious example. Eventually, genetics will make it possible to prevent parents from passing on congenital defects to their offspring. That will lead to problems of definition. How stupid or physically weak would a child have to be in order to count as defective? When it becomes possible for parents to ensure their children are born healthy, it will also be possible to create designer babies. By the middle of this century, anyone who wants a child with Einstein's IQ, a magnificent athlete's physique and a face like a Greek god will encounter only one obstacle: the fee. They will be able to find doctors happy to oblige them, in tolerant jurisdictions. Globalisation will make it impossible to control genetic medicine.

Apropos of jurisdictions, the future equivalents of the old East German sports ministry will not have to rely on anything as crude as steroids. Genetics would be a simpler route to gold medals, or to Nobel prizes. Here, we are no longer dealing with exciting developments. These are frightening ones.

Nor is it clear what we can or should do. There is a basic problem - the decline of religion. Many people still express a vague belief that there is something out there, which is about as theologically rigorous as reading the astrology columns. Few people have sufficient religious belief to provide them with a secure moral code.

Most of us do recoil from the notion that we are simply a biological assemblage. We do not like to think of ourselves as merely animals with a brain; we would wish to claim qualities which could loosely be defined as a soul. This helps to explain the widespread revulsion at the thought of human cloning.

Yet unless a God created this soul, what is it and where does it come from? If a deity did endow us with a soul, he is entitled to more than a vague sense of out there-ness. If God made us, it would be blasphemy to interfere with His handiwork. While, presumably, stopping short of the Christian Scientists, who are logical enough to shun all medicine as an interference with the Divine will, creationists should regard genetic medicine with extreme suspicion. But why should those who do not believe that God made them feel inhibited from remaking themselves?

In the immediate future, there is an answer: the Government. John Reid, the Health Secretary, has expressed himself forcefully on the subject of cloning, and his anger was more impressive than the usual claptrap of manufactured political indignation. Yet anger is not an argument, still less is it an ethical system. As a matter of medical commonplace, the NHS carries out hundreds of abortions every working day. Is it really so much worse to clone a foetus than to kill it?

Abortion in industrial quantities has deprived pregnancy of its sacramental dimension. Why should scientists be reluctant to move into a moral vacuum? We cannot regulate genetics by law, unless there is a moral code to underpin that law. But where is this to be found? Christianity? It is hard to sustain the Christian ethic on an à la carte basis; it also depends on belief in the Christian God.

That is still to be found in isolated pockets, such as the Vatican, whose statements on genetics have, as usual, been clear and self-confident. That said, will the Pope be heeded on cloning any more than he is on contraception? Nearer home, it will be interesting to see whether any senior Anglican cleric can take his mind off sodomy for long enough to say something useful about genetic medicine. But the world is not waiting agog for the Church of England's pronouncements.

In the 19th century, Prime Minister Salisbury said that anyone who believed the Christian ethic could survive Christian theology for more than a few decades was in the grip of a delusion. Nothing in subsequent history has refuted him.

In genetics, as in nuclear physics, scientific developments may have outstripped mankind's ability to control them. By the end of this century, nuclear power may have emancipated the globe from energy shortages. Alternatively, the use of nuclear weapons may have wrecked the globe, leaving, at most, handfuls of huddled survivors who - forget living to 150 - would regard three score and ten as an unattainable fantasy. Forget genetic modification; they will be hoping to have enough children with two arms and two legs, but only one head.

In the case of genetics, the benefits are now more apparent than the threat. But a fundamental question will arise. In a world without God can man find a moral basis for laws strong enough to tame the power of science?