The year is 2041 and you are dying. You smile beatifically at your loved ones and the kindly doctor who has helped you through these difficult times. Then you breathe your, for the moment, last. The doctor whips out a gleaming stainless-steel chainsaw and cuts off your head. Your body is bagged and burnt, the head frozen. Fifty years later they find the cure for whatever killed you. A new, better body is built using the genetic material in your head. Molecular-sized robots are injected into your brain to correct age and frost damage. You wake up and smile beatifically at your loved ones, who are also younger, fitter and immortal.
Virgin births are a pushover. Immortality, however, may take a little time. Nanotechnology the breeding of the molecular robots is only a gleam in the eyes of a few crazed Americans. People, heads and bodies are already being frozen, of course, and some wit has attempted to have these classified as not dead but rather suffering from "severe, long-term, whole-body frostbite". In any case, if it doesn't work, there is always "downloading". This involves transferring your brain, now known as wetware, as opposed to hardware and software, into a computer.
Weird science is with us again. The above examples are all catalogued in an American book soon to be published here called "Great Mambo Chicken and the Transhuman Condition: science slightly over the edge". It is a chilling, if hilarious, celebration of the apparent fact that, given time, we can do what we like.
Once relativity, quantum theory and space travel produced a garden of speculative delights. Then it all went quiet as science became green, caring, responsible and dull. But three developments have put the show back on the road: the unravelling of the DNA molecule, the understanding of the structure of proteins, and the technology that permits the manipulation of genetic material. From about 1980 these created biotechnology, genetic engineering and an almost limitless landscape of possibility. The problem is that they have also created an almost limitless landscape of anxiety that, this time, we may be going too far. As the Earl of Lauderdale put it in last year's Lords debate on the embryology bill, we may be "playing God with the most intimate and sacred centre of life itself".
For the moment we have only the first, sporadic intimations of what biotechnology may mean. The embryology bill itself was an early indicator of the issues involved, and last week's virgin birth debate was another. The fact of virginity alone raised fairly straightforward issues of social ethics. The scientific ethics come in when we start to think about specifying the type of baby we want - blue eyes, blond hair, whatever. That may be frivolous: it becomes sinister when we are able to offer perfection. Many may agree with the idea of aborting a foetus that will be born with muscular dystrophy. But what if we are told our baby may be short-sighted, or have ingrowing toenails? Will that warrant an abortion, so that we can try for perfection next time?
For the moment, biotechnology has hardly begun to enter the human sphere. The international effort to map the human genome catalogue - every piece of genetic information that makes us who we are - is progressing, with some medical fallout in the tracing of the genetic origins of disease. But, by and large, the revolution is still confined to industry and agriculture.
Yet, even here, the technology produces a certain queasiness. Some found the "geep" - an ungainly engineered cross between a sheep and a goat - difficult just to look at. Such eerie and artificial animals make us feel that the inner workings of nature are no longer free from our meddling. Our pastoral longings are affronted. Inspired by this shock, the greens in Germany have mounted a devastatingly effective opposition to any form of genetic manipulation. A Hoechst plant, intended to manufacture human insulin using genetically engineered micro-organisms, has had to remain closed for five years because of green worries.
After the second world war, science and agriculture happily told us that it was fine to spray our fields with DDT and any number of even more lethal chlorinated hydrocarbons. As Rachel Carson recorded in "Silent Spring", the book that launched greenery, science thought if you sprayed Clear Lake in California with poison at a concentration of one-fiftieth of a part per million, then all you would kill were the pestiferous midges. But the beautiful grebes also died, with poison concentration in their bodies of 1,600 parts per million. The food chain concentrated the toxin. Crude science had underestimated the complexity of nature.
But, perversely, this is precisely the argument in favour of biotechnology. Professor Brian Hartley, director of the Centre for Biotechnology at Imperial College, says that the subtlety and sophistication of the new science makes such blunders impossible. If, for example, smart biotechnologists rather than dumb chemists had produced thalidomide, there would have been no tragedy. It was the impurities that damaged the babies. Biotechnology is also green. Engineered micro-organisms can eat toxic waste and transform dirty industrial production.
There is an important and usually ignored point here. We happily banned DDT. But we did so only after it had successfully eliminated malaria from southern Europe. The molecular biologist Max Perutz has suggested we could have put off banning it until we had done the same for the Africans. Sometimes the risks of going with science may be less than those of going without.
Hartley, however, is not saying there is no ethical problem with biotechnology. He is saying that the knowledge will progress whether we like it or not. This fact is still not really understood outside science. The bishop who wrote to The Times after Hiroshima suggesting the formula for the atom bomb should be destroyed was missing the fateful truth that, in science, we cannot unknow things.
Any viable scientific ethic has to cope with this. Today we may congratulate ourselves for deciding that foetuses up to 14 days old can be experimented upon. Tomorrow we may have to wonder whether a frozen corpse has rights. The rate of progress in biotechnology makes this far more urgent than lay people yet realise. No science is growing as quickly, and no science produces more radical polarisations of attitude. Hard greens may say DNA is sacred, but the hippie scientists described in the "Mambo Chicken" book simply regard the human condition as irritatingly defective. If we can improve things, why don't we?
That view is the modern incarnation of the Nietzschean conviction that the only possible response to the death of God is to become gods ourselves. If the universe is the blank and pitiless place science seems to describe, then we have every right to do what we like. If this means downloading ourselves into electronic code, then so be it.
Except that, at some point, you have to ask exactly what is being downloaded. The reason the geep produces a kind of vertigo in us is that we imagine ourselves in the same predicament - manufactured, manipulated, our ultimate privacy invaded and, in some fundamental sense, wrong.
These wilder shores are, of course, either impossible or decades away. But, in the unease of the virgin birth or embryology debates, we can glimpse the ethical, psychological and philosophical anxiety that biotechnology will force upon us. It is the anxiety that arises from the awareness that nobody can tell us with any authority when to stop. It is the anxiety that we really might be turning into gods.
