Last week Jacqueline Jarret lost her appeal by one vote. The Supreme Court decided, 6-3, not to review her case, and so the lower-court decision holds. She has lost custody of her three daughters because she is living with a man she isn't married to.

It didn't matter to the Illinois court that Jacqueline Jarrett had been the primary parent for all the years of marriage and divorce. It didn't matter that everyone, even her ex-husband, described her as an attentive and loving mother. It didn't matter that the three children were comfortable and happy in this new "family."

No, the Illinois court agreed with the father that she had created an immoral atmosphere for the three daughters by living "in sin." And so they ordered the children to move eight blocks and one life style from mother to father.

But the story doesn't end here. The Jarrett case is a modern tale of conflicting values and conflicting parents. And there are plenty of both going around these days.

There are a million divorces a year in this country now. Another 1.1 million people are living together unmarried, and one-quarter of them are living with children. The Jarretts are just another accident case at the intersection of these changes.

It is easy to understand the feelings of both parents. The father's rage when his children were living under a different moral structure. The mother's anguish when she was punished by the court, though in her own mind she had behaved responsibly and lovingly toward her children.

These were two parents who differed wildly, irreconcilably, in their moral views. These differences were, I'm sure, a cause as well as an effect of their divorce. They often are.

But when the court was asked to intervene, it sided with the father -- and with the vengeance.

Never mind any other standard of caring. For the "crime" of fornication -- a crime to this day in about 19 states -- a mother was punished by losing custody.

In my view, the Illinois court made the wrong decision. The court record reeked of moralistic judgments, sprinkled with words like "fornication and "flaunting."

But, as the Supreme Court decision notes, the state court had the right to make that decision.

And that is, in some ways, the real story.

More and more often, the legal system is being called on to judge mother against father, life style against life style. The cases are all around us, fair and unfair decisions, innovative and conservative, pro-father and pro-mother.

In other Illinois cases, judges have ruled that living together is irrelevant unless the lawyer can prove that it has harmed the children. In Massachusetts, a lesbian mother is no longer "unfit" by definition.

At the same time, in a Chicago courtroom last week, 36-year-old Mildred Milovich -- a Brownie leader, a Sunday school teacher, a self-described "Supermom" who worked as a sales representative -- lost custody of her children to their father because of her job.

The beat goes on. In one courtroom, a father who left his wife sues for custody of his children because he has remarried and can offer them a "better life style" than she can on her clerical pay. In another case, a father wins custody because, the court says, boys are better off being raised by a man. Later, that verdict is reversed.

These are not ordinary decisions. There are fewer "ordinary decisions" these days. The standard for custody is now almost always "the best interest of the child."

This is a most elusive standard, made by judges full of good will and prejudice, caring and preconceptions. With the best of intentions, it can also end in the worst of injustices.

In most courts, mothers are still given the edge, as well they should be.

I am amazed at the number of fathers who come in claiming equal rights to the children they never raised equally.

But more and more often, custody is up for grabs. The judgments and the judges can be arbitrary. How do you judge which is better or worse for a child: an authoritarian, punitive father or a mother who chooses living together over marriage? A working mother or a working father?

The courts are left to weigh people and life styles, economics and psyches, according to the loose legal guidelines and their own values. Parents who can't settle, or share, are left to judgeshop, court-hop and hope.

And the Jarrett case is just the beginning.