The bare outlines of the O'Brien story are familiar, classic, even banal. Two young people get married. Nine years go by. He studies. She works. He gets an M.D. She gets a P.H.T. (Putting Hubby Through). Then he files for divorce.

In the old days, five or maybe 15 years ago, couples like Michael and Loretta O'Brien probably got a Traditional Divorce. The law back then was drawn by its architects to ask a moral question: Who was at fault for the breakup of the marriage? It was a messy design, but after a bit of wrangling, perhaps some perjury and a whole lot of moral judgment, a divorce was usually granted. To the "innocent" went the alimony.

More recently, such a couple faced a Modern Divorce. Between l970 and l980, the courtroom was trimmed of baroque moral judgments, streamlined for contemporary life. Fault was banned from the law because it was an anarchronism, rather like a gargoyle on a glass skyscraper.

The thoroughly Modern Divorce, with its pristine, hard-edged outlines, divvied up the past and the visible property -- a car, a bank account, a house. It was designed with a wistful belief in fresh starts.

But Loretta and Michael O'Brien are part of the avant-garde of legal architecture. Last week, they became the owners of a Post-Modern Divorce. A new pillar, a new touch had been added to the modern structure.

Loretta O'Brien claimed, and the New York Court of Appeals agreed, that Michael O'Brien's medical degree was just another piece of property. Since that property was gained during the marriage and with the financial investment of his partner, Loretta was entitled to a part of her ex-husband's future income. It is now up to a lower court to determine how much money will be hers.

The decision was not unique. There are now at least six states with similar cases on the books. In Michigan, a wife was awarded a share of a law degree. In Washington state, a wife got a share of her husband's license to practice dentistry. There are also six states that have ruled the other way.

The argument is intriguing because it comes out of the recent attempts to reform the divorce reform. Modern Divorce looked wonderful on the drafting board, but it has provided little shelter for women and children. As Stanford's Lenore Weitzman points out in her utterly convincing book, "The Divorce Revolution," divorce reform has been a financial disaster. Today, on average, the standard of living for a divorced woman and children goes down 73 percent in the first year while her husband's goes up 42 percent.

Under the roof of Modern Divorce laws, courts have treated husbands and wives, fathers and mothers, even M.D.s and P.H.T.s with an evenhandedness that is, in effect, unfair. Property has been divided both equally and inequitably.

Now, the Post-Modernists want to remodel a more livable space. Today, they argue, the major financial worth of a middle-class American family may not be in the bank account but in the company pension balance, may not be in a house but in an insurance plan. A couple's time and energy and money may not go into stocks and bonds but into a license or a degree. The courts are being asked to think about "career assets" when they tally up the property for any divorce settlement.

The trickiest of all those "career assets" has to be the one featured in the O'Brien case. The P.H.T. was always an honorary degree, a loving tip of the hat. It is the rare professional who doesn't believe at heart that he or she got that degree by individual labor.

One person studies. One name appears on a license. It isn't easy to price an investment in education when one doctor goes into brain surgery and another chooses missionary work, when one lawyer goes to Wall Street and another to Legal Aid.

At the same time, as Loretta O'Brien said, "I feel I should be compensated for the blood, sweat and tears of those years, when I had the whole financial burden on my shoulders." What is marriage if one person makes all the investment and the other is allowed to leave with the rewards? How different is her financial interest in a medical license from her interest in any other business?

On the whole, I approve of this new pillar of Post-Modern Divorce because it may shore up the fragile status of some divorced women. But it is still flawed. Indeed, the architecture of divorce has been under constant renovation for the past 20 years, but it never seems quite right. Fairness is as elusive as ever. Have you noticed how hard it is to find a sturdy structure when the one called marriage falls apart?