The appeal court judges who authorised the separation of Mary and Jodie, the conjoined twins, said that their judgment would be unlikely to have implications beyond itself; and it is obvious why they thought so. Twins conjoined in such a complex way are exceedingly rare and, presumably, even more rarely brought to term.
Nevertheless, the case is in some ways not exceptional at all, but part of a stream that is increasingly becoming a flood. The moral problem presented by the twins is not so much the phenomenon itself; it is that we now have the technical skill to attempt a disentangling of these babies, with a reasonable prospect of life for one of them. Not so long ago, neither could have been saved, and there would have been no legal or moral judgment to make - except, perhaps, behind the scenes, about whether to arrange a retrospective stillbirth for these manifestly doomed lives.
Technological progress is changing our existence at such a rate that every week seems to confront us with decisions about what to do in situations we have never encountered before. We try to apply our existing moral standards to them; and sometimes this works perfectly well. But increasingly, the advances are throwing up situations of such unfamiliarity that our normal standards seem of no help at all.
This is what has happened in the case of the twins. The relevant facts were not in dispute: everyone agreed that separation would involve the death of Mary while giving Jodie the chance of a reasonably normal life, and that if they were left conjoined they would both die. The problem was that familiar moral and legal guidelines could not provide an answer to the question of what to do. If Jodie and Mary had been ordinary, separate children, nobody would have doubted that it would be wrong to kill either of them, or to allow either to be killed if that could be prevented. As it was, Mary was (innocently) killing Jodie, and the only way to prevent that from happening was to kill Mary. Principles that, in familiar circumstances, would have seemed unexceptionable turned out, in this situation, to have incompatible implications.
When this sort of thing happens, the moral question must move to a deeper level. Why, exactly, do we normally regard killing as wrong? We do not usually ask the question, because its wrongness - in many circumstances - seems self-evident. But the answer is important, because it may determine how we should respond to difficult cases such as this one; and when it is asked, it becomes clear that the question has several possible answers. You may, for instance, think that the act of killing is simply wrong in itself. Or you may think that killing is wrong because it deprives the victim of life. The difference between these convictions is critical, because although in many parts of ordinary life they give the same answer to moral questions, they give different answers in the case of the twins.
These two ideas about killing seem to mark the real division between the two main sides in the case. The principal opponents of the operation seem to have believed that since the act of killing was wrong in itself, its commission would be worse than the omission of failing to prevent killing. The proponents, seeing the wrongness of killing in its causing loss of life, concluded that killing Mary would be justified if it resulted in the saving of one life, rather than the loss of both. This was essentially the point the judges had to decide - although they might not have put it that way - and their decision was in favour of life.
It is probably significant that the judiciary of a fundamentally secular state decided that in this case, saving life overrode the strict principle of not killing, while its main opponents - or, at least, its most organised and vociferous opponents - were the Catholic Church and associated pro-life groups. The difference between the two approaches is characteristic of two radically different world views, which coincide to a large extent with secular and religious beliefs, and yield quite different approaches to problems of ethics.
The view that has been at the root of western thinking - starting with Aristotle, and later adopted and modified by Islam, then Christianity - has been of a universe that is naturally orderly and harmonious, and in which all goes well as long as everything keeps to its ordained place. When things are out of their natural place, there is turmoil and restlessness. This view leads to a conception of ethics in which your duty is to understand your nature and your place in the scheme of things, and act appropriately. It is not your business to understand the whole: that is beyond you. You take it that God, or nature, has the whole under control, and will provide you with the guidance you need to act in that situation as you should.
The contrasting view of the world is that it is the result of the unplanned interactions of physical forces, and that the appearance of order in the living world derives not, as traditionally believed, from design, but from Darwinian natural selection. There is no underpinning moral order, and there is no natural state of things according to which all will go well. Understanding the nature of things in this kind of world tells us nothing at all about the way they ought to be: it tells us only what raw materials we have to work with and, in doing so, what we are up against. If things are to be made better, that depends on our working out criteria for what would count as their being better, and getting enough of a grip on the world to remould it a little nearer to our hearts' desire.
Even though these two contrasting views may allow for agreement about such matters as the prima-facie wrongness of killing, it is clear that they will have many different implications, and in particular, are likely to lead to very different attitudes to advances in technology. Both groups want to achieve as much good as possible and to guard against danger, but they have very different views about how to set about this. According to the "ordered universe" view, we should be concerned only with restoring things to the way they ought to be. We should try to heal the sick and save life; but we should not in any way play God and try to change the natural state of things. According to the other view, there is no natural state, and if we are to achieve any kind of harmony, we must decide what sort and try to create it ourselves. There are natural constraints on what can be achieved, but not on which of the possibilities we should try to achieve.
The fundamental question is which of these approaches is right, because if we act according to either, and we are in the other kind of world, we are going to be in trouble. We all want to make good use of our new powers and set up safeguards to prevent their doing harm; but they need to be of the right kind. Equally, if we have decided to accept one approach, we need to ensure that we are not distorting the way we think with assumptions inadvertently drawn from the other school of thought. In particular, much of our supposedly secular thinking comes loaded with presuppositions from the other side of the divide - but working on the old, "ordered universe" autopilot is quite unsuitable for the new, unplanned world.
The first problem - which is to some extent widely recognised - is about how far we should press the use of our technological abilities in our attempts to preserve life. During most of the history of medicine, doctors could do so little, that it was obviously right to try to keep their patients alive, and to give a higher priority to life-saving than to less urgent kinds of care. But can those impulses still be regarded as leading us in the right direction?
Doubts of this kind have been hovering on the fringes of the twins debate. Even the parents, while expressing their resignation to the will of God, added that it would anyway be impossible to care properly for a disabled child in their poorly-equipped community. They would apparently have preferred both children to die, and many people would agree. Can this feeling be justified?
If it can, it is not because it would be better for Jodie herself to die. She will probably be disabled but, as disability rights campaigners insist, most disabled people are glad to be alive. Nor is it because her life should be treated as less valuable, intrinsically, than others. The question lies not in the value of the life, but in the cost of saving it. Given that our resources are finite, Jodie's separation from Mary, her intensive care, the many further operations she will need, and the long-term support for her disability, must all be at the cost of other people who are waiting for operations or need care. If she stays with her parents, it will be at enormous personal and financial cost to them. We hate this kind of thinking; but no state of any kind - religious or secular - can take the view that all life is beyond price; and in a secular state, trying to make the best of a morally unstructured universe, it is morally essential to address questions about the acceptable cost of saving any life.
There is a serious problem here about the whole point of medicine. We value medical advance because of its capacity to rescue us from the pain and disease that have ruined so many lives. But with every advance that lets us replace hips or remove cataracts comes the ability to rescue and sustain more and more lives that would have had no chance in nature, and may remain seriously incomplete, while absorbing huge resources.
We also need to recognise the moral imperative to confront other alarming questions, for similar kinds of reason. For instance, the secular state would have allowed the abortion of Jodie and Mary - given their abnormality - very shortly before their birth; can it really be reasonable to say that such a short time can make the difference between their lives being disposable and their being entitled to this extraordinary rescue attempt? There may, perhaps, be a reasonable secular answer to this question, in terms of the need to have a point at which people acquire full human rights: there can be no secular justification for refusing to raise it.
There is also the familiar question of the difference between killing and letting die, and how, in cases where it has been decided to allow someone to die - perhaps a patient in a persistent vegetative state - it can be regarded as better to let them starve slowly than to kill them outright. In a morally ordered world where there is an absolute prohibition of killing, the distinction may (perhaps) make sense. Our instincts are all, still - and rightly - against killing: but in a universe not underpinned by moral order, there may be times when the moral reasons for overriding our impulses are themselves overriding.
Meanwhile, in another part of this forest of new technology, more or less the converse is going on. Science is offering us the possibility, and in some cases the actuality, of wonderful new ways of overcoming the burdens that nature has placed on us: curing genetic diseases, regrowing missing limbs, defeating infertility. But, in these contexts, we seem alarmed at the prospect of headlong rush, and recommend the so-called precautionary principle. While in the case of life-saving treatment, we go on until given positive grounds to stop, here we tend to think the other way - we should stop until given positive clearance for moving on. So we establish bodies such as the Human Fertilisation and Embryology Authority to set up controls to ensure that only what is safe passes through. And we rule out certain kinds of procedure altogether: human cloning, even if only for hugely beneficial therapeutic purposes (as proposed in a private member's bill earlier this month), or germ-line gene therapy.
We want these new procedures to go ahead as safely as possible, and so caution is needed. But we need to take care not to put the road-blocks in places where they do nothing at all, or just stop the rescue services. However, this is exactly what often happens. Here is a minor, local example: the ethics committee of a hospital's assisted conception unit, charged with deciding which applicants should be given treatment. This was not a matter of priorities or NHS resources; the women were paying and the unit had great capacity. Why then was a committee deemed necessary?
The official brief was to consider, in each case, the interests of the child. But there were as yet no children whose interests had to be defended, since the whole question was about whether they should be brought into existence; and this could only be against their interests if their lives turned out to be worse than nothing. The committee had no reason to think that any of the applicants would produce children who were likely to be better off dead, so they must, presumably, have interpreted their brief differently: they must have been concerned with something like a predicted standard of happiness, and therefore the general good of society, rather than the interests of particular children. However, if this is our concern, then we should surely be equally concerned to screen the naturally fertile women who can have children no matter how feckless they are.
It may be argued that although it would be too great an infringement of liberty to stop unsuitable women from having children, we can at least refuse to help them get pregnant. But women who are infertile for relatively minor reasons are automatically treated, free, by the NHS, without having to go near an ethics committee.
There seems, in other words, no good reason at all for putting IVF applicants through a screening process. But the motivation - as opposed to the justification - may be suggested by the distinction between treating infertility and offering IVF treatment. There is no difference between the two in prospects for children, public expense, or the moral responsibility of helpers. The difference is that one is about attempting to restore an organism to its natural function, while the other involves meddling with nature by making life in test tubes. IVF treatment can be seen as dangerous only in the context of an "ordered universe", where nature is likely to fight back if tampered with. Without that assumption, it seems impossible to think of any justification for special screening in IVF clinics.
This is only one minor case, but there seems good reason to suspect that in many cases where danger is alleged, and firm controls demanded, what we are really afraid of are the dangers of our hubris. Consider, for example, the idea that somatic gene therapy (the treatment of individuals suffering from a genetic disease) is acceptable in principle, but germ-line therapy (removing the problem for future generations) is not.
It is said that something with such wide-ranging consequences is too risky. But in how many contexts would we refrain from curing something we already knew to be badly wrong, just on the grounds that something else - for the existence of which we had no evidence whatsoever - might possibly go wrong? It looks as though, once again, the real fear is of interfering with nature: of making a new kind of person, rather than curing the disease that afflicts someone who already exists.
The moral is a general one: if we are not to lose the good that our new technology can bring us, we must ensure that our calculations of danger are not being infected by presuppositions drawn from ancient fears of natural retribution. Equally, we must take care not to lose the benefits of our medical progress because ideas drawn from the same kind of world view make us incapable of asking certain kinds of question. Care is needed in all our dealings with the unknown - but the wrong kind of care may be worse than none.
Janet Radcliffe Richards's Human Nature After Darwin is published this week by Routledge (£13.99 paperback)