IS THERE any child who has not, while blowing bubbles, allowed the bubble mixture to spill unnoticed from the other hand? There was a spate of bubble-blowing in the crowds gathered in Dublin to celebrate the large vote in favour of a constitutional amendment to permit same-sex marriage in the Republic; but the metaphor applies more readily to the Churches in Ireland and, to a similar degree, in the United Kingdom. As the religious authorities have concentrated on the iridescent beauty of their ethical arguments, their churches have been emptying, though not completely unnoticed.

The RC Archbishop of Dublin, Dr Diarmuid Martin, remarked after the vote: "I think really that the Church needs to do a reality check . . . to look at the areas where we really have to start and say: 'Look, have we drifted away from young people?'" It is interesting, and encouraging, that he put it that way round rather than repeat the common suggestion that it is the young people who drift away. He will know, as the Anglicans know, that it is not enough simply to look for new ways to present old doctrines. As the Archbishop of Canterbury said after the UK vote on same-sex marriage two years ago: "We may or may not like it, but we must accept that there is a revolution in the area of sexuality, and we have not fully heard it." The evidence is there: the British Social Attitudes survey in 2007 recorded that 47 per cent were in favour of same-sex marriage. Five years later, in 2012, the figure had risen to 56 per cent. The Irish vote at 62 per cent shows that the tide continues to flow in one direction, and is probably lower than in the rest of the British Isles. An opinion poll for BBC Radio last year suggested that 68 per cent were in favour.

Of course, theology is not a democratic discipline. A statement from the conservative Core Issues Trust warned against "simple majoritarianism". To agree that same-sex marriage is right just because the majority believe it to be so would entail having agreed that it was wrong hitherto, just up to the point when the balance tipped. Followers of a Christ who was abandoned by all must be ready to belong to a minority. On the other hand, all Churches have mechanisms for reassessing doctrine in the light of new evidence and understanding. And, as Archbishop Welby reminded the General Synod last year, the Church of England, in particular, is not "a closed system".

This paper has argued before now against the view that allowing same-sex marriage somehow undermines the institution. The continued withholding of the Church's blessing from certain couples, on the other hand, will increasingly undermine the Church, if not marriage itself. Rather than seek to find ways to get young people to agree with it, the Church ought to consider whether it should agree with the young people.