Today the High Court rejected Tony Nicklinson's plea to allow doctors to end his life. Nicklinson is not terminally ill, but for the past seven years he has been "locked in" as a result of a stroke: fully conscious, but immobile, able to communicate only by blinking. With the full support of his family, he had asked the court to extend the defence of necessity to cover doctors who acceded to his request. As the law stands, any doctor who carried out his earnest request might have found themselves facing a charge of murder. He also hoped to establish that his human right to a private life (under Article 8 of the European Convention) included the right to choose the manner of his death.

The result isn't a surprise. Nor will it be the end of the matter: the family had already announced their intention to appeal should the decision go against them. In the end, though, even the highest court in the land might well conclude, as this hearing did, that such a profound change in the law could only be made by act of Parliament. "It is not for the court to decide," said Lord Justice Toulson this afternoon, "whether the law about assisted dying should be changed and, if so, what safeguards should be put in place." Yet there seems little immediate prospect of legislation. Despite decades of debate and the fact that public opinion has long been sympathetic to euthanasia (provided that there are strict safeguards to protect the vulnerable) Parliament has so far proved reluctant to act.

Instead, the law finds itself in a position of moral incoherence. On the one hand, it refuses to draw distinctions that most normal people would regard as obvious. As the Lord Chief Justice made clear in 2010, upholding the murder conviction of a mother who ended the life of her severely brain-damaged son, the law "does not distinguish between murder committed for malevolent reasons and murder motivated by familial love." A law that puts a loving mother in the same legal category as Ian Huntley, sentencing both to life imprisonment (albeit with different tariffs), is clearly deficient. Nor can the Crown Prosecution Service be relied upon to act with common sense and compassion in such cases. 

At the same time, the law draws distinctions that are, in moral terms, pedantic. For example, it makes what is taken to be a significant distinction between actively ending someone's life (for example, by administering a lethal cocktail of drugs) and passively doing so by withdrawing nutrition. The latter has, since the Tony Bland case twenty years ago, become an almost standard procedure in cases where a patient is assessed to be in a persistent vegetative state with no hope of recovery. The difference means almost nothing to the person concerned - who is unable to express a preference either way. Tony Nicklinson himself could choose to refuse nutrition. This would condemn him to a slow and agonising death, and increase the suffering of his wife and daughters who would be forced to look on helplessly. But it would be legally OK. Death by lethal drugs would be quicker, painless and dignified. But it would be murder. 

If Tony Nicklinson were a dog, it would not merely be legal to end his suffering, it would be a criminal offence not to do so. The RSPCA routinely prosecutes pet-owners who cannot bear to see their beloved animals put down. Perhaps the dog, if it could talk, would express a wish for its suffering to end; perhaps it would cling to life. Society assumes, though, that to be merciful and compassionate is to put the animal to sleep. Why should a fully conscious and intelligent adult human being be treated with less humanity and compassion than a dog? 

The usual answer is that the law exists to protect vulnerable people who might otherwise feel under pressure to choose death so as not to be a "burden" on their loved ones. But their must be other, less cruel, ways of protecting the vulnerable. And the current law risks imposing another sort of burden on the families of people in Tony Nicklinson's position: a stark choice of watching someone you love in agony and asking to die, or acceding to their request at the risk of being convicted of assisted suicide or even murder. 

It's also sometimes argued that to allow profoundly disabled people the right to euthanasia would undermine the value of the lives of all people with similar disabilities. This must be nonsense. To respect human life is to respect more than the continuance of bodily functions: it is to afford respect and dignity to individuals, and that means allowing people to make decisions about their own lives. Including the ultimate decision to end it. 

A civilised and compassionate society will allow, even encourage, people to make the most of life whatever physical or mental disabilities they may have. We will shortly see at the Paralympics a triumphant demonstration of the fact that disability is no bar to achievement. It's possible to have even Tony Nicklinson's level of disability and lead a positive and worthwhile, even successful, life: just look at Stephen Hawking. But forcing someone to live against their will, as a demonstration of society's attachment to the sanctity of life, is neither civilised nor compassionate.

There is, in fact, no real conflict between the sanctity of life and the right of someone in Tony Nicklinson's position to end it. If human life has any special meaning over and above any other sort of life, it is because human beings are capable of self-reflection, of mental anguish, of conscious suffering, which includes the knowledge that one's suffering will end only in death. In such a case as Tony Nicklinson's, such human characteristics only add to the predicament in which he finds himself. For him, the right to die has become indistinguishable from the right to life.

What such a situation reflects, perhaps, is a continuing desire on the part of the law (or of its defenders) to want to punish suicide. A nominally secular society continues to see suicide not as a viable option - even an affirmation of life, because it is an affirmation of autonomy - but as a moral and personal failure, an admission of defeat. This was the mentality that for centuries refused suicides burial in consecrated ground. It is an attitude that ultimately limits human dignity, while at the same time pretending to exult it.