Dr Martin sent to the rescue Fintan O'Toole

There is a famous, and therefore probably apocryphal, story about the late Frank Cluskey asking about Michael D. Higgins's absence from a crucial meeting of the Labour Party's administrative council, writes Fintan O'Toole.

Discovering that the Galway TD was unable to attend because he was observing an election in Latin America, Cluskey is said to have remarked that "Given a choice between saving the world and saving the Labour Party, Michael D. always chooses the easier option." Given a choice between using Archbishop Diarmuid Martin to save the world or to save the Irish Catholic Church, however, the Vatican has chosen the harder option. The very fact that it is sending one of its global stars to succeed Cardinal Connell in Dublin is eloquent testimony to the serious state of what used to be one of the church's most reliable constituencies.

Though he won't thank us for it, some of the credit for Archbishop Martin's appointment has to go to those of us on the wife-swapping sodomite wing of Irish life. Even 10 years ago, the Vatican would have felt it was wasting a valuable talent by sending a man of Diarmuid Martin's eminence and abilities to Dublin. You don't send your best generals to the quiet fronts. Even in the early 1990s, it could be assumed that the effective leadership of the Irish church could be given to a quiet, gentle, unassertive figure like Sean Brady. Orthodoxy and obedience were enough for the fairly straightforward task of keeping the old show on the road.

Now, thanks to the success of liberalism and the self-destruction of the church's political power, the Dublin archdiocese is a job for a serious player. I never thought I would see the day when becoming Archbishop of Dublin was a step down in the world. But it says much for the seriousness of the situation that in taking the job a Vatican luminary like Diarmuid Martin is like a senior vice-president of a major multinational corporation putting his loyalty to the company first and taking over the reins at a troublesome under-performing outpost.

This means, nevertheless, that Irish public life is about to get a pretty serious adornment. Diarmuid Martin is not just a more distinguished figure than anyone in the Government, he is a match for the best of them even as a political operator. If he is as astute as he seems, he could have huge, and hugely beneficial, impact on Irish public life.

Diarmuid Martin's public career as the Vatican's most able diplomatic fixer sums up both the worst and the best of the church. Because of the church's peculiar status as a non-UN member with voting rights at UN conferences, he wielded global influence first as secretary of the Pontifical Council for Justice and Peace and then as ambassador to the UN at Geneva. His record could be used to make a strong case for either an obscurantist dogmatist or a courageous champion of social justice and human rights.

The first strand was most prominent at the UN Conferences on Population and Development in Cairo in 1994 and on Women in Beijing in 1995. Archbishop Martin headed the Vatican delegations that pushed a medieval line: condoms cause AIDS; women who had been raped in war should not be allowed to use emergency contraception; women in developing countries have no interest in individual rights, but only want to serve the community; adolescents have no right to confidential education on sexuality; homosexuality should not be recognised.

He urged Catholics worldwide to lobby their national delegations to oppose the draft text of the Cairo conference, which supports gender equality, education and the empowerment of women as keys to the stabilisation of the world's population. He also declared "unacceptable the document's continual implication that family planning and contraception are synonymous terms" and urged the UN to champion so-called natural methods of contraception.

At the same time, however, Diarmuid Martin has also used his position to argue for the relief of Third World debt, for global justice, for the enhancement of the social dimension of human rights and against the war in Iraq. He gives the impression of being a man who has thought seriously and felt deeply about the idea of human equality.

He must be astute enough to know that Diarmuid Martin the anti-condom campaigner would be an irrelevance in the Ireland of the 21st century. While he no doubt seriously believes all that stuff, and is perfectly entitled to preach it to a dwindling band of the faithful, it has no purchase on Irish life now. Catholics are not going to stop using the pill. (Not least because if they did, repeated maternity leave would close most Catholic schools and hospitals.) Gay men and lesbians are not going to go back into the closet. The ban on divorce is not going to go back into the Constitution.

On the other hand, there is an immense hunger for the courageous expression of public values. The vacuum left by the collapse of the old Catholic certainties has not yet been filled. There is rampant cynicism about politics. The old authoritarian rule of Christ and Caesar hand in glove is gone for good but a talented, eloquent and internationalist church leader could still rescue a new kind of authority from the rubble.