Recent poll results indicate that people's attitudes to abortion are undergoing considerable change. So-called pro-life groups are alarmed at what seems like a swing towards permissiveness and a lowering of moral standards. So-called liberals hail it as progress, with Ireland moving into line with the modern world.

As so often happens, extremists with simple slogans cloud the issue, and serious debate becomes extremely difficult. This has been borne out in the Irish context over the past few decades. Public statements have often produced more heat than light.

Politicians, clergy and ordinary citizens have aired their stronglyheld views, but the sad fact is that this extremely important topic has seldom been discussed in the full context of moral responsibility, paying attention to all the factors that need to be taken into account to reach a morally-balanced decision.

Space does not allow a full presentation of the matter here, but it may be helpful to draw attention to some of the confusion.

The two issues, of personal moral responsibility (for mother, father, doctors, nurses and all involved), and what needs to be done in terms of legislation, are closely connected but are distinct and separate issues.

Furthermore, Catholic Church teaching quoted in debates is not always presented as "teaching" but at times comes across simply as a series of declarations. One is reminded of Aristotle's dictum that "no teaching takes place until someone has been taught".

Some statements are presented in isolation, coming from a reactive position, which can give an unbalanced picture. Committed Christians in today's world of critical intelligence want to be convinced of the truth of a teaching before they accept it as true, especially since teaching in moral matters is not a matter of revelation of divine mysteries.

To arrive at a morally-responsible decision about abortion, one needs to pay attention to all the elements needed for moral discernment. One needs to be attentive (look at all the facts); be intelligent (that is, really understand the facts); be reasonable (reason about the facts and assess the values involved); and be responsible.

To be attentive means to look at all the facts, clinically, factually, without moral labels.

The claim that abortion is murder is simply not true. Murder is a moral description, taking account of motive and circumstances. Not all killing is murder, as our Christian tradition has always held in the cases of self-defence, capital punishment and just war.

Then one needs to examine the motives for a particular action or omission and ask questions about who is involved, when, where and how the activity will be carried out, what the foreseeable consequences are. Are there viable alternatives to the action being considered?

All of these questions need to be answered clearly and as fully as possible before a responsible decision can be arrived at. Morality is about values and there are situations where values are in conflict and one or other may have to be sacrificed for the sake of a higher or more urgent one.

Both the mother and the unborn baby have an equal right to life, but if it is not possible to save both a choice has to be made. Traditional moralists for centuries accepted this.

The classic example of choosing one life above another was the lifeboat which could save only two out of five people. The moralists never said that any one person had a greater right to life, but they developed criteria, or what might be called preference principles, to enable a choice to be made, for example a mother of a family would get preference before a 70-year-old single man.

Much of the confusion and disagreement in moral discussion comes from a careless use of language. For example, it is simply not true to say that human life is an absolute value. The Catholic Church has always seen it as a near-absolute, but the traditional teaching admits that it can be sacrificed, however sadly, in certain circumstances. This is often forgotten when speaking of a foetus in the womb.

A further confusion arising from careless use of language concerns the word "innocent". One can become quite lyrical with the statement that it is hard to imagine anyone more innocent than the unborn baby. It is true that the unborn baby is morally innocent (not deliberately and personally responsible for the threat to the mother), but the insane attacker intent on killing me is equally innocent in the moral sense.

"Innocent" is from the Latin innocens, i.e. not harmful or threatening. But in fact neither the foetus nor the insane attacker is innocent in the sense of "harmless". Both are harmful, and the same logic must apply to both in the tragic case where one life has to be sacrificed to save another.

The right to self-defence is a basic human right upheld by a long Christian tradition, and the fact that the harmful life happens to be that of an unborn baby does not change that. There is room here for preference principles.

Another careless use of language is the "right to choose" slogan. Every human being has a God-given right to choose, but this right is limited by corresponding duties and, most fundamentally, by the basic right to life of other human beings, even though unborn. One can choose not to be pregnant, by avoiding intercourse or by taking contraceptive measures, but there is no right to conceive and then to destroy the new life conceived.

Abortion is an agonising and complicated problem involving many issues (value and protection of human life, freedom of choice, right to privacy, public policy and private conscience etc) and any simplistic approach is counterproductive. But it is not unconnected with other moral issues such as housing, employment, social security and education. It is not enough to be pro-life: we need a consistent life-ethic.

Fr Sean Fagan SM is a lecturer in moral theology in the Milltown Institute of Philosophy and Theology and the author of Does Morality Change?, published recently by Gill and Macmillan