Mary Holland's hope (The Irish Times, November 5th) for a tolerant national debate on abortion is likely to be shared by most people. We can all sense a spirit of good will and mutual respect in the air today. For the first time in our lives, there is a prospect of reconciliation in the North which respects diversity and the human worth of all members of society.

The old days, when the powerful elements in Northern society diminished the human rights of the disadvantaged, using laws to achieve this purpose, have largely given way to an inclusive model of society, in which all voices can be heard and everyone's dignity respected. These voices do not chorus in unison: the range of political viewpoints in the North is no less extensive today than it was 30 years ago.

The difference is that today civil society is based on the principle of equality, which is the foundation of democracy. Respect is given to those whose political, social or ethical vision differs from one's own.

Abortion has been the subject of public discussion and debate, North and South, for two decades. Before, there had been virtual silence on the subject. Twenty years is a long time, but the subject of abortion touches issues of such profound human significance that it takes time for all of us to absorb the vision of those who see the issue differently from what might be called our original position. Our initial response may be to reject the opposing vision, but anyone of good will who reflects on the subject will have to be impressed by the sincerity and persistent commitment of those taking the opposite view. It may be comforting to denigrate them but, as the years go by, denigration gives way to a recognition that the issue is one on which people of good faith differ radically.

What consequences follow from this? First, and most obviously, that debate on the issue of abortion should be conducted respectfully and sensitively. The Pro Life Campaign has since its foundation sought to do this.

At the level of substantive law, there are distinct difficulties in seeking to accommodate pluralistic norms with the protection of human rights. We recognise that this is so in a wide variety of contexts internationally. Respect for pluralism does not require us to authorise ceremonial mutilation, domestic violence, slavery or infanticide, even though all of these activities have at some time in some societies received conscientious approval. If a husband were to convince us that he sincerely regarded the physical chastisement of his wife as conducive to family discipline and authority, we would not be obliged to give him a legal entitlement to act in accordance with his vision. On the contrary, the protection of his wife's right to bodily integrity calls for a legal foundation. Similarly, with a parent who in good conscience thrashes a defenceless child.

The issue of domestic violence is of course entirely separate from that of infanticide which in turn differs from abortion; but the question of whether the protection of human rights should be defeated or reduced in order to accommodate pluralistic concerns is one that calls for an answer in all of these cases. What should the answer be?

No one advocates that a person should be permitted by law to do everything that he or she conscientiously adjudges to be permissible. Plenty of people have felt justified in killing, stealing and knee-capping, but no coherent theory of political philosophy supports their entitlement to do so simply because this is consistent with their moral vision.

The case of abortion has its own distinct aspects. Perhaps the most significant is the fact that some people regard unborn children as less than human. They point to the obvious fact that their development is at an early stage, that they are tiny and that they are dependent.

Others are willing to accept unborn children fully within the human community. They are conscious that societies (including our own) have at times failed to recognise the full humanity of particular groups. Irish people have been the victims, and at times the authors, of racism and religious discrimination. We should not accept the principle that any human being, of any age, should be denied the right to life on the basis that the person who contemplates terminating that life does not conscientiously regard that human being as a member of the human community.

It is sad to learn that Mary Robinson has become an advocate of legalising abortion in what she defines as "limited " circumstances. This would, she says, be "a kind of coming to terms with the problem instead of exporting it and moralising about it".

If we introduced an abortion law on the lines of the British regime we would have established a regime of abortion on demand. Any law narrower than this would not satisfy the criterion that Mrs Robinson proposes.

It is a tragedy that Mrs Robinson should have lost sight of the human rights of unborn children. She is a person who has spent much of her life as an advocate of the human rights of the powerless and the defenceless. If she could make the protection of the lives of the unborn part of her agenda, this would be an immeasurable contribution to human rights in their most inclusive sense.

William Binchy is Regius Professor of Law at Trinity College Dublin, and Legal Adviser to the Pro Life Campaign.