How sacred is life? What is life, anyway, and how can we judge whether it has become intolerable? Most politicians squirm before such questions, so medics are left with the legal risk and the moral burden of deciding difficult cases.

Last week the High Court was asked to decide whether life support to baby MB should be ended. It heard evidence from doctors that his existence was intolerable and from his parents that he enjoyed some quality of life. The child has a degenerative disorder called spinal muscular atrophy which leads to almost total paralysis. He cannot breathe unaided. For periods he has to wear splints on his hands and feet and soon he will need assistance to open his eyes. A doctor says that his mental function does not appear normal, but the parents testify that he reacts to them and to videos. The judge comments that it is the first time a court has been asked to make a life or death ruling on a child who has “near or full” cognitive function. We expect judgment next week.

The father, a Muslim, said: “It was God that gave us life and God will take it.” He believes that we should use technology to continue existence as best we can and accept death at a moment not of our choosing.

Meanwhile, another British baby, Charlotte Wyatt, clings to life. She was born three months prematurely two years ago with serious brain, lung and kidney damage. In her case, where again the parents have argued for keeping her alive, a judge has ruled that doctors need not resuscitate her if she enters a medical crisis.

I do not take the view that life, any sort of life, is always better than death. I see a strong case for enabling adults to refuse treatment that prolongs life when it has ceased to have any quality for them. By analogy, an equivalent decision should be permitted in the case of a small child and generally authority should rest with the parents.

On this side of the Atlantic adults are being allowed more opportunities to choose their time of dying. In December 2004 Mrs Z, suffering from an incurable brain condition, travelled to Zurich where her life was ended. Although those who brought about her death would have been breaking the law in the UK, our High Court allowed her husband to help her to travel to Switzerland.

Another example of the trend is that parliament has legislated on living wills. They enable adults to declare in advance that they would not wish to be kept alive if they became incapacitated and unable to communicate. Draft guidelines would make doctors who disregard such instructions liable to prosecution.

Some doctors will not be able to square their consciences with living wills. I am not against them but I will not sign one. I cannot foresee my reaction to an incurable medical condition. I expect that in a pragmatic and compassionate way my family would talk to the doctors and they would relieve my suffering and bring my life to a peaceful end before too long.

Holland, which has permitted adult euthanasia since 2002, is now setting up a committee to regulate the ending of dying infants’ lives. There are five conditions that must be met, including a second medical opinion covering the hopelessness of the condition and the suffering of the child, and the consent of the parents.

There is at present little sign that Britain intends to emulate either Switzerland or Holland. But the Dutch example is interesting because (as I read it) under the new system baby MB would live, since his parents clearly do not consent to withdrawing support.

Indeed it would be surprising to me if the judge in the MB case ruled for termination. The doctors, although evidently genuine in their concern for the child’s suffering, cannot be sure that he experiences unbearable pain and the parents assert that his life is worth living. The case might be even more difficult than it is if the child clearly had no cognitive awareness and was evidently in pain, and yet still the parents argued for continuing his life.

There could, I suppose, be circumstances where parents were alleged to be placing their own interests above the child’s. But it would be a difficult judgment and it is territory that the Dutch will avoid.

The British system is undeniably messy. It is appalling that parents must engage in adversarial court proceedings with the doctors charged with their child’s care.

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