Hmm. A well-meant question, unfortunately phrased. When “values and virtues of the past” are mentioned in this connection a host of awful phantoms rises: shotgun weddings, dynastic unions, conjugal rights, divorce as disgrace. Old voices grate: Father Knows Best, No Wife of Mine Works. Fiction and memoir bring us trapped or beaten women, nightmare wedding nights, henpecked husbands reaching for the weedkiller. We mop our brows in relief: how much better to live now, with easy divorce and the option of just shacking up! This reaction afflicts even those of us who have been lucky enough to score 25 years and be still balancing on the marital tightrope. Only idiots are smug: when I consider the men I would have married in my early twenties if they’d only asked, I quite see the point of divorce.

Children, of course, are the chief stumbling block to the idea that marriage doesn’t matter. Every study confirms that cohabitees are more likely to split up than the married; children suffer. Allowing for honourable exceptions, children of cohabitees also do less well in general than those whose parents marry. There are strong, happy families without marriage but bald statistics suggest that it helps. For that reason alone, it shouldn’t be written off.

So cast aside both atavistic terrors and moral strictures, and ask why? What can marriage add to a modern relationship? It is a cliché to dismiss it as “a piece of paper” — so are your mortgage deeds. In law marriage offers certain securities, now extended to gay couples in civil partnership: notably the ability to inherit freely and to be next-of-kin. It has no tax advantages because this Government removed them, but it makes it easier to establish paternity and financially harder to separate.

But the practical legalities are the least of it. There are deeper effects. Even in the age of serial divorce, marriage still holds a solemnity and public seriousness not found elsewhere in human relations. It is the point where a private, intimate relationship is dragged into the light and affirmed in public. It is a way that two individuals formally entangle two families, whether the rest of them like it or not. When you do it, you suddenly become aware of taking on lifelong responsibilities towards your in-laws as well as your spouse: the knot you tie strengthens the wider net of society. It is a brave thing: it publicly states an intention that you will at least try to be loyal for life. If we cry at weddings it is because of the touching immensity of that hope.

Any couple will tell you that even if they lived together first — most of us did — marrying changes things. Usually, I think, for the better; but when marriage is used to patch up a failing partnership it can destroy it. That this latter disaster sometimes happens is, I think, another indicator of the genuine significance of that “piece of paper”. It is a backhanded compliment to the power of the deal.

The longer a marriage endures in reasonable harmony the more mysterious a possession it is. Long marriages get little good press, though they should interest us: this was one of the most riveting aspects of ITV’s 49 Up, its latest seven-year progress report on the primary class of 1963. We saw children growing up, marrying, abandoning grandiose dreams, becoming middle-aged. The most interesting were people like the London cabbie, whose marriage was happy at 28, rocky at 35 or 42, but which weathered storms until at 49 he seems benignly set for the long haul with his first and only wife.

In an age of unprecedented longevity this is a pretty amazing trick to pull off: perhaps in gossip and fiction we should study couples who last rather than focusing endlessly on those who can’t. Long-term pairs, far from being stuck in a rut, display remarkable adaptability: they have to seek modern personal freedom within a framework of steady fidelity. Marriage — that public and solemn commitment — does help. It clarifies our expectations. It reduces life’s uncertainty in one direction, making adventure and risk possible in others. If your whole attention is on keeping your partner sweet, you will not have nearly so much to offer the world in general. Marriage is not essential but it helps.

Marriage is not only good for the children: it is interesting and constructive and worth trying even if you fail. Objections to it are mainly timid and depressing. Men, we are told, dread commitment and financial blackmail. Women fear enslavement. Both sexes, mind you, may reasonably be appalled by the hoopla of the wedding industry and the prodigal ostentation — fed by silly celebrity culture — which makes the “average” cost of a UK wedding more than £14,000, including two parties and a thousand quid for the video.

Faced with this nonsense it is not surprising that some couples decide that marriage is for show-offs, and spend the money on real life. Yet the pother of flashy weddings can be separated from marriage: think of Alan Bennett’s parents, who had to wed at dawn because his employer wouldn’t give him time off. They lasted until death. Even now, even the quietest wedding brings the same primitive frisson of going public, changing the world. It’s worth doing. I don’t believe its time is over.

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