Research last week revealed that within the next 10 years, less than half of us will be married. JOAN SMITH raises her glass to life without Mr Right
It seems like an anecdote from another age. It was only the 1970s, but my announcement that I was going to live with my then boyfriend provoked a family row of Victorian proportions. My father ordered me out of the house at dawn, ignoring my protests that I was being sensible - I had turned 21 - and refusing to listen to my feminist argument that marriage was a patriarchal institution. I had first articulated this thought at the age of 14, in front of my mother's friends, and it was not widely subscribed to on a council estate in Basingstoke.

Not every girl gets the opportunity to be in the vanguard of a social revolution and, boy, did I seize it. Parents, landlords, even friends who were quietly living with their boyfriends but concealing the fact, were confronted by my living-together-and-proud-of-it arrangements. Not for me the hasty tidying of our flat to remove traces of cohabitation when his parents threatened to visit, or the pretence that we were engaged and intended to get married one day. My dad had brought me up to be a revolutionary and, having missed the big political campaigns of the 1960s, this was my contribution to changing the world.

I was miffed that so few people seemed to appreciate I was making a political statement, following in the footsteps of radicals like Mary Wollstonecraft. (Some time later, in the 1980s, I wavered and married someone else, a perfectly nice man, in a register office in a grim part of east London - a turn of events that plunged me into such gloom that I started writing my first novel. The divorce was a relief to both of us.) But, as I think about what relationships are going to be like in the 21st century, it is satisfying to reflect that I was simply ahead of my time.

Some time during the next decade, according to research published last week, the proportion of the adult population that is married will fall below half for the first time in history. Statistics are notoriously dry when you stare at them on a page, but for once they reveal a dramatic alteration in how we live in this country: marriage has gone from being compulsory, the only form of intimate relationship not frowned upon, to an optional extra. At a time when all sorts of pundits are making rash predictions about the next millennium, it is possible to speculate about this one area - love and sex - with confidence because all the trends point in the same direction.

The miserable old days when young women "got into trouble" and shamed their families are over. The stigma of illegitimacy has been removed from the law and almost 40 per cent of births in England and Wales took place outside marriage in 1998, the latest year for which figures are available. This does not suggest a reluctance to fall in love or be part of a couple, for three-fifths of the births were registered by parents who were living together. What it does show is the increasing unpopularity of marriage, and a move towards serial relationships in place of a single lifelong commitment. Married couples, straight and gay cohabitees, single people with and without lovers, are already living side by side, in a social fabric considerably more colourful than even 20 years ago. And everything suggests that this will continue to be the pattern in future.

If you are a social conservative - Melanie Phillips, say - this is little short of a disaster. "The advantages of marriage to both women and men are well-attested, as measured in the accounts of general health and well being," she claims in her new book, The Sex-Change Society: Feminised Britain and the Neutered Male. Funny, then, that so many people are failing to recognise its advantages: the number of marriages in England and Wales dropped from 352,000 in 1987 to 273,000 in 1997. A recent article in Population Trends, the quarterly journal of the Office for National Statistics, suggests that the number of cohabiting couples will double to almost 3 million by 2021.

It is also a little odd that Phillips writes nostalgically about the punitive measures that used to discourage unhappy couples from seeking a divorce in Britain, and which she says still apply elsewhere: "In most countries, the marriage vows are reinforced by social ostracism and financial costs for those who separate, legal penalties for the spouse who is primarily responsible for the breakdown of the marriage and positive support for marriage in the form of social and economic privileges." If marriage is so great, why do people have to be coerced and bribed into staying in it?

Helen Wilkinson, in a report published by the think tank Demos, takes a more pragmatic view than Phillips. Arguing in favour of a recognition that "the institution of marriage cannot be rebuilt if people continue to make commitments they cannot sustain", she suggests introducing marriage contracts with a time limit, perhaps of 10 years. This does at least admit that, for many people, the prospect of spending their entire adult life with one partner - a span, thanks to CONTINUED FROM FRONT

modern medicine, of perhaps 50 years - is not an achievable or even a desirable goal. Marriage, Wilkinson believes, "needs to be brought up to date, liberated from the grasp of the church and the state, and given to the people whose interests it should serve."

This goes to the heart of the problem, which is what is left of marriage - what precisely is its point - if it is democratised in this way? Some couples, it is true, enjoy making a public statement of their feelings for each other. But most of us could do that at a party, in front of our friends and family, without signing a binding document. For others, the relationship works just as well without the trappings; the most committed couple I know, who live together with their child, have both been married but not to each other. Another friend, in her late 20s with a young baby, says she has decided not to marry her partner because she knows that her feelings might change. Equally, they might not, in which case they will simply go on living together. Why complicate matters with a legal contract which, in the hands of lawyers, might lead to bitter arguments?

One of the things that has emerged about marriage, in recent decades, is that it serves men better than women. The statistics are not very recent, but research has suggested that three-quarters of divorces are initiated by women. And, among divorcees and the widowed, twice as many men marry again. The conventional explanation is that divorced women have fewer opportunities, partly because men gravitate towards younger women second time round, but I suspect this conceals a genuine difference in attitude. The single and divorced women I know want boyfriends, perhaps even live- in lovers, but they don't yearn for a husband.

I do not find this surprising. It has never been clear to me why promising to stay with one person throughout your adult life is morally superior to having a series of relationships, as long as they are conducted with passion, honesty and affection - and without spite when they come to an end. The philosopher Plato has much to answer for here, allowing a character in his Symposium to suggest that human beings are split down the middle at birth, as a punishment from the gods, and have to spend the rest of their lives seeking their missing other half. This 5th-century BC version of the idea that there is only one Miss or Mr Right is romantic tosh, but no less potent for that. It certainly does not make sense in a world with a population of 6 billion people.

It is a curious fact that sentimental notions like these have been a cover for a form of marriage that was, in its original conception, about as mercenary as it is possible to imagine. Although Phillips summarises traditional marriage as "an institution based on the duty to protect the interests of the next generation", it would be more accurate to describe it as a means of transmitting property elevated to a moral principle. Marriage as we know it in this country dates back only to 1753, when church and state got together and devised a union that turned women into nonentities. Even as conservative a figure as the present Home Secretary, Jack Straw, recently observed that the idea of a golden age of marriage had been exaggerated - and he may have been speaking more truly than he knew.

Professor Lawrence Stone, the most eminent historian in our century of marriage, has written unequivocally: "It is easy to forget that under the patriarchal system of values, as expressed in the enacted law as it endured until the 19th century, a married woman was the nearest approximation in a free society to a slave." Most of the changes that have taken place in marriage have been the result of a long battle by women to liberate wives from the burden it placed upon them. The question it raises is whether trying to modernise marriage isn't a bit like attempting to devise a benign form of slavery.

But what about children? Cohabiting couples, we keep being told, are more likely to split up, with devastating effects on their children. Yet, since cohabitation and serial monogamy are clearly here to stay, it would be far more sensible to have a practical discussion about how to ameliorate the consequences of a break-up instead of trying to force everyone back into lifelong unions. Ironically, it is often the pressure to save a doomed marriage or relationship that prolongs it to a point where both partners are at each other's throats, making an acrimonious outcome more likely.

One measure that would help children is to lift single parents, of either sex, out of poverty by manipulating the tax system and raising the minimum wage - but that is anathema to social conservatives. Another is to persuade ourselves to relax about the idea of children growing up in unconventional families, which may consist of both full and step-siblings. The urge to form an intimate bond with another human being is as powerful as ever, but it does not mean we have to make promises we cannot keep. Marriage is a human invention, not a sacred rite. I have no hesitation at all in predicting that millions of people, in the next century, will recognise that it has outlived its usefulness.