I don't know if I am in the majority of heterosexuals in this, but here goes: when I contemplate the idea of one man having sex with another, I feel a certain unease. On the other hand, the fact that many of us don't want to think about it is hardly a reason for stigmatising it, let alone legislating to that effect: after all, most of us have felt discomfited, and not only as children, at the thought of our own parents making love.
Yet we are almost obliged to think about such gooey matters because of the public row over the Coalition's clear intention to legalise marriage between people of the same sex. Obviously, marriage is about much more than sex (some would say that it's the alternative); but there's no doubt that much of the opposition to the proposal stems from a visceral distaste at the whole idea of physical union between men.
The word "unnatural" crops up time and again – and was invoked by the leader of Scotland's Catholics, Cardinal Keith O'Brien, in his fire-and-brimstone broadside against the Government's plans. Yet it is the most natural thing in the world to men and women who are attracted physically only to those of the same sex – I have conducted the necessary enquiries, to satisfy myself on this point. And since homosexuality occurs in nature quite spontaneously, the Cardinal ought to consider the possibility that it forms part of God's plan for the Universe.
In common with the Church of England (but with greater intensity and vigour), the Catholic Church asserts that the primary purpose of marriage is to have children; that a relationship which biologically cannot create such offspring is incapable of being a true marriage – and, therefore, should not be called one. Yet this must sit ill with heterosexual couples who are, for one unfortunate reason or another, unable to have children – or, indeed, if the bride is simply past the menopause.
Doubtless the churches would argue that there is another purpose of marriage which is socially desirable whether or not there is a prospect of children: it is for two people to signal their absolute and permanent commitment to one another – "in sickness and in health, until death us do part".
This is the element of the marriage ceremony that never fails to move relatives and friends (always providing they approve of the union in the first place): yet that depth and promise of stability and commitment is also of profound value among couples of the same sex. This, presumably, is part of the reason why David Cameron told a slightly startled Conservative Party Conference last year that "I don't support gay marriage in spite of being a Conservative. I support gay marriage because I am a Conservative."
Others in the Coalition express it slightly differently. The Liberal Democrats have a distinct distaste for Cameron's eulogising of marriage as an institution: the arguments of their people in the Government – such as the Equalities Minister Lynne Featherstone – rest on the idea that if marriage is everyone's right, then that should mean everyone: to exclude same-sex couples from this form of joyous union is an unacceptable form of discrimination.
Here we must enter the world of linguistics rather than of morals. According to the opponents of the Government's proposals, the word "marriage" is understood to mean the union of a man and a woman. They say that it is not for the state to redefine a word, just to satisfy a pressure group's campaign: they darkly invoke George Orwell, who wrote how totalitarian governments twisted language to suit their political objectives.
In a slightly creepy article in The Daily Telegraph, Lynne Featherstone, denouncing the objections of the former Archbishop of Canterbury, George Carey, wrote that language was "owned neither by the state nor the church. So, it is owned by the people." She went on to write that "Marriage is a right of passage... why should we deny it to people who happen to be gay?". Er, no, Minister, there isn't such a thing as a "right of passage". The word is "rite" – something quite different. Perhaps I am underestimating Ms Featherstone: maybe this was a very clever way of indicating that she had no interest in marriage as a sacred thing, but merely as a secular "right".
After all, there is not the slightest suggestion in any of the Government's proposals that same-sex marriages should be made obligatory or even available within churches, mosques and synagogues. To this, Cardinal O'Brien retorts, somewhat bizarrely: "Imagine that the Government had decided to legalise slavery but assured us that 'no one will be forced to keep a slave'. Would such worthless assurances calm our fury?" His claim, in so far as I can understand it, seems to be that by legalising marriages between same-sex couples, the Government would be taking away our right to marriage as we understand it, and replacing it with something much less precious.
Somehow, I don't think this will turn out to be the case; at least in the sense that heterosexual couples who are married in churches in years to come would ever feel that their union and their commitment is somehow diminished or devalued because, in civil ceremonies elsewhere, men are marrying other men, and women other women.
The truth is that in the Catholic Church, at least, marriage has for centuries been something quite distinct from that understood by the civil law. For example, it does not recognise divorce, whatever the law says: someone married in a Catholic church can get a legal divorce, but if he or she later tries to get another Catholic marriage, it will not be granted – on the grounds that this would be nothing less than bigamy. In other words, the Church will be free to consider that same-sex couples are not married, whatever is the case in the eyes of the law.
If we are supporters of the idea of a separation between church and state, and on the whole that seems rather better than the alternatives, then it should be perfectly possible to operate a dual system, in which same-sex couples have unions recognised as marriage by the civil authorities, but not necessarily by the churches, which have their own special notions of what constitutes sacred union – the rite of marriage, as opposed to the secular "right".
In this sense, the church can aspire to the role of Alice to Lynne Featherstone's Humpty Dumpty ; you will recall that when Humpty Dumpty says "When I use a word, it means just what I choose it to mean – neither more nor less", Alice retorts, "The Question is whether you can make words mean so many different things."