Leading article: A debate that will intensify

Yesterday's High Court ruling in the case of M, a 51-year-old woman with brain damage, introduces some useful clarity into a situation that had been dogged by uncertainty. M's family had argued that she was in pain and asked that feeding and hydration be withdrawn so that she should be able to die with dignity. The judge, Mr Justice Baker, refused, citing medical evidence that she had "some positive experiences" which might be "extended". "Although not an absolute rule," he said, "the law regards the preservation of life as a fundamental principle."

If there is any doubt about the extent of brain damage and the individual's state of consciousness, the bias must favour life. This is not to take a fundamentalist "pro-life" position, it is to recognise the distinction drawn by doctors between a "persistent vegetative state", where there is no sign of brain activity, and "minimal consciousness". In the former, life support is generally withdrawn. In the latter, it is now clear, it should be maintained.

The family's case for ending feeding and hydration deserves sympathy. Their knowledge of M and their belief that she would prefer to die humanely than to continue in her present dependent state must be respected. However, it cannot be taken for granted that all relatives in similar situations will always have the best interests of the patient at heart. This is why M's independent legal representation was important. The likelihood is that such cases will become more frequent as techniques for detecting consciousness advance.

It must also be acknowledged that, for all those who are heartened by yesterday's judgment, there will be many who deplore it, fearful that in similar circumstances their lives might be prolonged against their wishes. This should not, however, militate against the ruling; rather it should serve to encourage people to make living wills which set out their wishes and help create a climate in which doctors and hospital authorities respect them.

With life expectancy rising and, with it, the incidence of Alzheimer's and other age-related conditions, public discussion about when and how treatment should be withdrawn will intensify. Mr Justice Baker's ruling may not be the last word, but it contributes to that debate.