Imagine three sisters. One is very pretty and marries a top footballer; they have no children and it is a short marriage before she leaves him for an international celebrity. The second sister marries a clergyman and has several children; the marriage ends after 30 years as he is moving into retirement. The third sister never marries; she stays at home and nurses first their mother, who has a disability, and then their father, who has Alzheimer's, and dies without making a will. Which of the three sisters will get the windfall, an amount sufficient to keep her in luxury for the rest of her days, when her relationship with a man comes to an end? And which one most needs and deserves financial support, even of the bare minimum?

The divorce courts are still trying to put women in the position they would have been in had the marriage not ended. The message is that getting married to a well-off man is an alternative career to one in the workforce. If you are married to a clergyman with a tied house and little income, you will get next to nothing, and of course not even the continued occupation of the vicarage. If your parents do not make a will in your favour, and you are over the age of majority, you might be able to make a claim under the Inheritance (Provision for Family & Dependants) Act 1975, but to be eligible the claimant has to have been economically dependant on the deceased, and in the case of the carer daughter, it was more probably the other way round.

The law is of course gender neutral on the face of it. Men too can expect to continue in the style of living to which they have been accustomed if they have the good fortune to divorce a wife who is wealthier than they are. Guy Ritchie reportedly received about £50m from Madonna, the largest ever settlement made for a man. He was worth about £30m and she £300m at the time. Here are some other examples of how maintenance is allocated on divorce. Of course they are all well-off families, for the poor have nothing to allocate. Beverley Charman was awarded £48m after a 28-year marriage during which she pursued no outside employment, a sum legally notable because it went far beyond what had once been the yardstick, namely the spouse's reasonable requirements.

Mr and Mrs Miller married in 2000 and divorced after 3 years, with no children. He was then 40 and she 35, and he left her for another woman. She earned £85K a year and had no assets; he had £17m or so and a huge salary. The award to her of £5m was upheld all the way on appeal. Mr and Mrs McFarlane had three children after a marriage that lasted 16 years. She gave up her career as a solicitor to be a mother. The court of appeal awarded her half the matrimonial assets and £250,000 a year for five years. Her appeal against the time limitation of five years was successful. In the case of White v White, the legal costs of the couple were £500K to gain assets of £1.5m when both their appeals were dismissed by the House of Lords. So a clear first point to notice is that the costs of disputes may amount to as much as the assets. This is because of the lack of certainty. So the procedure is bad and the theory and effects that underly the awards even worse.

Maintenance law has not been thoroughly overhauled since 1857. It has been left behind by social developments. Most women, even with children, now work or are expected to work; they claim equal pay and opportunities in employment; there is contraception to enable a family to be planned, and more women are entering higher education and the professions than men.

It is contradictory if family law assumes that a woman can and should stay at home and care for their children and be compensated for that on divorce, while society calls for women to take 50% of top jobs.

Just under half the workforce is female, and 70% of married women work, even mothers, although the work rate of single mothers is lower; 40% of marriages break down; more women will become widows or single and have to keep themselves; 50% of divorces are of marriages that lasted nine years or less. But the concept of female dependency on the male continues to permeate maintenance laws.

More than that, maintenance laws cushion and legitimise the attitudes of employers who discriminate against women, because they are aware of the "meal ticket for life" mentality.

The strongest argument in favour of maintenance is that the divorced wife will have raised children and her career has been undermined by marriage. Given that most women work, this is a matter of choice; childcare does not take up the whole of a long marriage; and the wealthier the spouses the less likely that there was much to do by way of housework.

The notion of "compensation" recently put forward by judges as a basis for awards is unrealistic. It is covering up for the fact that our divorce rate is high because in part the law has made it easy, and we are punishing men and trying to limit the welfare liability of the state by making them pay over assets and pension funds. Perceptions of what might happen to their funds on divorce may affect men's willingness to commit (and women's, if they have means). This adds to the high cost to society of marital breakdown overall. Regardless of the theories, some certainty about the way to split assets may be more important than total fairness, especially when considering how difficult negotiations may impact on the children's wellbeing.

One could actually categorise divorce cases into four. Short marriages with no children; couples on welfare; middle-income couples with a house and not much more; and the wealthy.

For the poor and unemployed there can only be a token order, a reminder to the father that he has children for whom he is responsible, and that the order could be revisited if circumstances change. For the slightly better off, there is reallocation of the house and there may be repayments of legal aid to be made. Then there is one law for the rich and one for the poor, because the wealthy wife gets a lump sum and has no need to pursue, as the poorer may have to, the enforcement of periodical payments.

It is no wonder that England is the divorce capital of Europe and out of step with other European countries. The notion that a wife should get half of the joint assets of a couple after even a short childless marriage has crept up on us without any parliamentary legislation to this effect – the judges have developed the law in a paternalistic and unprincipled fashion that has departed widely from parliamentary intentions.

Europeans have entirely different attitudes and laws from ours. Most European nations could offer an attractive model for reform in this country. What is needed is an end to discretion and the recognition of autonomy in contracts, with the aim of reducing costs and promoting negotiation in a better spirit. Matrimonial and non-matrimonial property would have to be defined. Premarital assets should be excluded, especially when the parties are older or have been previously married, and so should legacies and gifts. Subject to the existence of an agreement made by the couple to the contrary, the postmarital matrimonial assets could be divided equally, but in the case of a short marriage, say three years or less, there should be no division at all, but the parties should go back to the position they were in before they married. If there are children and the home is too small for sensible division, then it should as now be retained for the occupation of the carer, with eventual sale and division when the children reach 18.

What of the future of maintenance? Certainly it should cease to be payable if the wife cohabits with another man. Should it be awarded at all? If we had a divorce system based on misconduct, then it would be easy to find a rationale pinned to guilt and innocence, but that is unlikely to be the case ever again. My extreme view, which will never hold sway, is that no maintenance should be payable unless the claimant spouse is unable to work or has the care of young children. The primary aim of maintenance should be rehabilitative; it should be permanent only for older women and the incapacitated who are not cared for by the state. That is the price of easy divorce granted on a theoretical ground of irretrievable breakdown without fault. The government has shirked responsibility for re-examining the law; no Royal Commission, no parliamentary debate. It is time to call for reform, not by judges struggling to cope, but by our legislators.

This is an edited extract of Ruth Deech's Gresham College lecture.