ON billboards around Dublin there is a car advertisement showing a picture of a contented, thumb sucking baby in its mother's womb, with the caption "the most comfortable place in the world", the car in question presumably being the second most comfortable place. The womb may be a `comfortable place but in today's world it's not a safe place. Every year, for as many as 50,000,000 babies, their mother's womb is the most dangerous place in the world.

Why is there so much controversy about abortion? I would suggest that the controversy is caused not so much by a failure to appreciate the arguments against abortion but by a failure to imagine the unimaginable. Infanticide can be justified on many of the same grounds on which abortion is justified, yet most people would reject infanticide. Why? If abortion is morally acceptable, then it is difficult to see why infanticide should be unacceptable.

After all, what possible moral difference can a change of location make? If it's wrong to kill me, the wrongness of the act surely does not depend on where I happen to be. The difference between the acceptance of abortion and the rejection of infanticide is not one of principle, it is simply that in infanticide what is being done is plainly evident, whereas in abortion the brutal reality is masked.

The threat to the life of the mother is perhaps the most highly charged emotional element in the abortion debate, the one that contributes most to the failure of imagination. Let's cool it down a little by looking at the facts.

A major study published in the Iris A Medical Journal found that over a 10 year period, there were just 21 maternal deaths in relation to 74,317 births. The cause of death in each of these 21 cases was analysed and the report concluded that the availability of induced abortion would not have reduced this number by even one.

In most jurisdictions where abortion was introduced initially to deal with the so called "hard cases" it has proved practically impossible to stop short of abortion on demand. In the UK, only 0.25 per cent of the abortions performed between 1974 to 1990 were on the stated grounds of "risk to the life of the pregnant mother". Nearly 90 per cent of the abortions performed on UK residents were for psychological reasons.

The situation is even more stark for non UK residents. Here, risk to the life of the mother accounted for only 0.02 per cent of the cases, with almost 95 per cent of the cases being based on the alleged risk to the health of the mother. The maxim that "hard cases make bad law" is nowhere more evident that in the question of abortion.

Those advocating the complete prohibition of abortion are not proposing the denial of any necessary medical treatment for the pregnant woman, even where that treatment poses a threat to the health or life of the unborn child. All treatment has some unintended side effect or other, sometimes serious, sometimes trivial.

The general principle is that of doing as much good and as little harm as possible. The amount of harm that can be risked is obviously related to, and must be proportional to, the seriousness of the illness or condition to be treated.

In Ireland, all human beings, from conception to death, are recognised, as being fundamentally equal in respect of their essential humanity. If, two persons are equal in a given respect, then whatever can be done to one in that respect can also be done to the other.

If it is legitimate directly and intentionally to take the life of the child to protect the life of the mother (as the Supreme Court judgment in the X case would seem to allow), then if ever a situation should arise in which the mother were deemed to constitute a threat to the life of the child there could be no principled objection to directly and intentionally taking the life of the mother! This position is, of course, plainly nonsensical and no one in his right mind would defend it but so too is the reverse.

It is sometimes argued that those who personally oppose abortion should, not prevent its legislative provision for others on the grounds that this is intolerant. But the function of law is, among other things, to prevent the oppression of the weak by the strong, and in a democratic society no one is free to tolerate the systematic and legal oppression of any group by another. And among human groups, the unborn are unique defenceless and weak. They are therefore most in need of legal protection.

Practically, what is to be done? There are only two options. The Oireachtas could legislate in accordance with the X case judgment. This clearly would have to permit abortion in a very wide range of circumstances, a position that is clearly at odds with the decision of the people in 1983. Anyone who is in favour of the legislative route is already committed to accepting abortion.

The only other route is a referendum that will give the people the chance, if they so decide, to reiterate their opposition to the direct and intentional killing of the unborn child.

It has been claimed that such a referendum would be divisive. So what? All issues of significance are divisive. Divorce was divisive (very evenly so, in fact) but that did not deter liberal activists from pushing for a second referendum on the subject.

It is sometimes said that the issue is too complex for general public debate. This argument is both condescending and false. The general point at stake is quite simple and the public is well able to grasp and vote accordingly.

In this bloodiest of centuries - the century of Hitler, Stalin, Amin and Pol Pot - if we've learnt anything, surely it is that no problem is solved by killing another.