Bruce Anderson: We're not ready to extend lives indefinitely

Immense political problems will be caused by having infinitely repairable bodies

It was an example of how not to conduct a debate. Although it was inevitable that the Government's embryology Bill would sunder the scientists from the Catholic Church, there was no need for both sides to resort to stereotypes and emotive language.

As the children would say in the playground, the Catholics started it. Cardinal Keith O'Brien, the most senior Scottish RC, anathematised the scientists in language of fire and brimstone. The Cardinal would have us believe that the men of science, devoid of scruple or conscience, have as little regard for human life as they do for laboratory rats.

The problem with rising to the top of a hierarchy which has a 2,000-year tradition of authority and obedience is that everyone laughs at your jokes; no one tells you that you are talking balls. The Cardinal needs wise advisers.

Offered easy debating victories, the scientists and their friends enjoyed themselves. According to them, the Cardinal and his acolytes are still regretting that the church did not burn Galileo. The Government then poured oil on the flames. Gordon Brown claims that he has values. He has also expressed his desire to listen: to reconnect government to people. There is only one problem; he does not know what "connection'' means.

Nor has he much grasp of values. If he did, he would have understood that the embryology Bill involves questions of conscience. In such circumstances, it has always been taken for granted that MPs should be given a free vote. Thoughtful voters would expect the Commons to treat the issue seriously and to come to a vote only after a long, thoughtful discussion. It could have been an opportunity – God knows, necessary – for the Commons to rehabilitate itself with public opinion.

Instead, Mr Brown decided that there should be a regimented debate and a whipped outcome. A dithering week later, the threat of ministerial resignations forced him to change his mind. But before he next uses the words "values'' or "listen'', would the Prime Minister please look them up in a dictionary and ponder their meaning?

It would still be possible for the Commons to hold a thorough debate. One of the ministers who forced the PM to retreat is Miss Kelly, a devout Catholic who is a member of Opus Dei. Miss Kelly is an intelligent and thoughtful woman: qualities she has been given no chance to display in her seven years as a minister. This could be her opportunity. It is not enough for her to vote according to her conscience. We want to hear what she thinks. But it is unlikely that we will be allowed to do so.

However good the debate, irreconcilable differences would emerge. The scientific arguments could not be conclusive, for two questions are at issue which could not be more basic: life and humanity. Who should control life? What is a human being?

On the first point, the Catholics have a clear answer. Life is God-given. The purpose of the earthly journey is to enable the individual soul to grow towards its Redeemer and Maker. Nothing else matters, including the pain and suffering to which flesh is heir. We owe God a life, and eventually a death.

That is the theology as I understand it. There have always been practical problems, such as war and capital punishment. But these have been exacerbated by modern medicine. The Roman Church has not been skilful in its response.

In the 1960s, it lost one battle which it should not have fought and another one which should rack the conscience of all good Catholics. The unnecessary one was contraception. By trying to prohibit it, the church turned most Western Catholics into sinners. It also risked the denial of birth control to those in the third world who desperately needed it.

It would have been better if the Holy Church had preserved its forces for the onslaught of abortion. Fifty years after it was legalised, within strict limits, abortion has become the French letter of last resort. In the UK, nearly 200,000 foetuses are killed every year; no one seems to care. In a nominally Christian country, the sanctity of human life has been brutally compromised.

There is only one way in which the Church could reverse the abortion defeat: an alliance with the scientists. One assumes that in the course of this century, some lab will invent a wholly reliable contraceptive with no harmful side-effects. Once that happens, abortion would be almost unnecessary. But that would not reinstate the Almighty in his dominion over human life. There will be other discoveries.

Most of us assume that we are a compound of cells. Through the genome project and related research, scientists are discovering more and more about those cells. Before the end of the century, they may be able to produce a complete cellular map of every human body. At the same time, using the individual's DNA, laboratories could create spare organs and cells to replace damaged tissue.

If we are nothing more than a collection of cells, all our most profound emotions and experiences are just a chemical formula. As such, the formula can be discovered and the cell reproduced. In time, it ought to be possible for scientists not only to replace ageing or damaged brain cells, but to programme the new cells with all the memories, feelings and humanity of the outgoing ones, just like transferring data from an old computer to a new one. Unless the Almighty has ensured that the human being's hard drive includes a soul which is not accessible to medical science, there is no reason to believe that our bodies will not be infinitely repairable.

In the short term, this will cause immense political problems. By the middle years of this century, as a result of the genome project, it will be possible to extend human life by 30 or 40 years. But for the first few decades this would be an expensive business. So imagine the complaints. In the advanced West, the mass of the population will demand that they too have access to these life-lengthening procedures, even if it consumes the entire GDP. When most of the inhabitants of non-Western nations realised that the potentialities of long life were being denied to them, the tensions between the West and the rest would increase.

It is probable that none of this will happen – not because the cellular researchers will fail, but because other scientists will pre-empt their work. Stephen Hawking was asked recently why we had not received radio messages from civilised beings elsewhere in the galaxy. He replied that before becoming capable of sending such messages, any civilisation would already have destroyed itself by the use of terrible weapons.

It is more than likely that the same outcome will befall mankind. But on the off chance that the human race does survive the next century, we ought to start thinking about the implications of cellular medicine. Throughout history, most humans have wished for a longer life. In the next phase of history, they may receive one. While it would be premature to quote the old adage. "Don't wish for something, for fear you may get it'', the onward march of medical science is going to burden humanity with unimaginably complex problems.