It began as a quarrel about the two companions' professional roles, and gave way to a profound and unexpected rupture. For a long month, each kept up a brittle silence that mocked their 10 or more years of confidences. Finally, WAMU-FM radio talk show host Diane Rehm and her estranged friend Jane Holmes Dixon, an Episcopal priest, agreed to try the unconventional -- to review the blow-up together with their therapist.

"For the most part, the therapist listened," says Rehm, 49. "She had us describe how much the friendship meant to both of us. We hadn't expressed it before out loud in quite that way, even though Jane and I knew how important it was in terms of sharing what happened with our husbands, with our children and so forth . . . It's frightening to recognize you can risk losing someone who's become as important to you as a member of your family, if not more so."

The friendship survived, strengthened. The therapist, instead of finding the women's request odd, commended their ability to face what many don't: the central role friendship plays in our lives.

Especially women's lives.

Women's friendships, dismissed or derided from the time of Aristotle, are commanding new respect as they take over more and more roles from today's scattered families.

The idea that "men talked about important things while women babbled about trivia . . . kids, diapers, family life and what was the best soap to use" no longer washes, says psychologist Lillian Rubin, in an age when women friends not only share confidences but may also help rear the children of one another's failed marriages, trade critically needed professional support and even nurse dying companions.

Once, such alliances between women were viewed as exceptions. The category included suffragists Elizabeth Cady Stanton and Susan B. Anthony (who helped raise her friend's seven children); first lady Eleanor Roosevelt and journalist Lorena Hickok; writer-lecturer Helen Keller and her teacher Annie Sullivan; anthropologists Margaret Mead and Ruth Benedict.

Now, many reports by female authors are declaring that women's friendships in general, compared with men's:are deeper and more numerous at every stage of life; fill emotional needs unmet even by strong heterosexual relationships; nonetheless, are regularly dumped in favor of romantic alliances; and, hampered by time constraints and geographic mobility, will continue to be fragile until we confer on them some of the public status of the family they are replacing.

The distinguishing feature of women's friendships, claim the writers, is a greater degree of intimacy attributed to female biology and psychology: "The near-possession of her being by means of the feeling she has for you," writer Simone de Beauvoir described it. Whether the intimacy results, as Rubin says, from a girl's thorough identification with her chief caregiver in infancy -- almost always mother -- or, as author Elinor Lenz claims, from a woman's reproductive capacity, the result is the same:

"Women . . . are never entirely clear where their identity ends and the identity of another person begins," says Lenz, coauthor with the late anthropologist Barbara Myerhoff of The Feminization of America (Jeremy Tarcher, $15.95). "The identity boundaries are looser and more fuzzy, whereas men have a much clearer idea of theirs . . ."

This blurring of identity, says Cindy Marano, 38, figured in her occasional hikes and river trips with her friend Tish Sommers. Sommers, founder of the Older Women's League, a national women's rights organization, died last week of cancer. She was 70.

"The most intimate moments," says Marano, "weren't so much the times when we were struggling around an issue or where the differences in generation or social upbringing mattered much. They were the moments of going over a rapid where the rush of the water or the sense of the power of nature was an enormous bond . . ."

The effect has remained. "I carry with me a sense of carrying on her life in some of what's ahead for me."

The closest of friendships foster a mutual challenging of values difficult to accept in other relationships, even intimate ones. Says Rehm: "Friends can say, 'I really have a problem with what you are doing,' and it doesn't have the same feeling as when you hear it from a spouse. You have the courage to say, 'Well, what do you mean?' even when your back goes up. Friends do ask those kinds of questions."

Honesty among friends, however, can be compromised by the need to be liked. "If I'm angry with my husband," says Eva Margolies (The Best of Friends, the Worst of Enemies, Dial Press, $16.95), "I don't think, 'How should I put this?' I just scream my head off. Whereas if I'm angry with my friend, I think, 'Are my expectations of her too high? What is her life like now? Am I being sensitive to her needs or am I being totally selfish?' "

The wish for intimacy and exclusivity in women's friendships can also cause corresponding problems -- among them, jealousy.

Rubin's dedication of her book Just Friends (Harper & Row, $15.95) to four of her closest associates, "Barbara, Dorothy, Kim and Michael," produced a classic reaction among the women. "Barbara felt very much I let her down when I didn't dedicate the book to her alone," says Rubin. "Dorothy who lives in Alaska had the least trouble with it, but she rationalizes that she's far away. Kim and Barbara have an active competition."

"It's like children saying, 'If you're my best friend, you can't be someone else's friend,' " says the Rev. Dixon. "It has happened between Diane and me, but I think we've worked through that."

Sometimes jealousy results from unequal job success. Margolies started out several years ago as a songwriter, doing most of her work with one friend. Despite their efforts, Margolies won a contract for songs she had written with someone else.

Her friend's initial response, says Margolies, was sympathetic: " 'Of course I feel bad but I understand you have to do what you have to do.' Then she didn't call for four months after that. The relationship almost ended. Only many months after we began speaking again could she tell me how threatened, how envious she felt, how she could not cope with our relationship at the time."

Another problem, which can catch women off guard, is the sometimes frightening intensity of a friendship.

Says Rubin, "In some fundamental way, women remain connected to each other. Just as we never fully separate the infant from her mother, there's always a replaying of that relationship. That's why we're always reaching for that relationship and why it's often accompanied by some fear . . . that we'll be taken over again, we'll lose our autonomy."

This fear, she says, can be strong enough to make a woman drop a relationship.

The strongest attachments are typically in adolescence, when they help teens make the break from family. In girls, according to Rubin, friendships then "take on a Siamese-twin-like importance." Then the search for, and settling down with, a mate often takes priority, and it is several years before same-sex friendships regain importance.

In old age, close friendships are life supports. Author Gloria Naylor (The Women of Brewster Place, Linden Hills) recently wrote in Essence magazine about two Mississippi housemates, aged 85 and 91, whose friendship saw them through 60 years of work, marriages, deaths and moves. "We just lonesome without one another," one said.

There's also a sexual component to the fear of closeness between women.

"When there's not a man to buffer it," says Margolies, "the intensity is not only very strong but terribly threatening. I've talked to single women who, although they're not consciously attracted to close friends, were beginning to wonder if something was wrong with them because when they were with the friends, they didn't even feel they needed a man that much." Jealous husbands and boyfriends can compound the problem. Even though Rubin says research confirms that women's "friendship outside of marriage takes the heat off inside," a woman who has become accustomed to "stealing time" from a male competitor to see a woman friend is disturbed to find herself acting in a way she thinks more befitting an illicit lover.

"We're dealing with a very homophobic society," says Margolies. "It's interesting that 100 years ago, heterosexual women used to write letters to each other that had very much the sound of a heterosexual love relationship. That was considered normal."

It would be a shame, the researchers agree, if such fear were to keep women from recognizing the growing importance of their friendships and the need to strengthen and preserve them.

"Women need each other's support as much if not more than they need men," says Margolies. "We have to undo the message we got from our mothers and early friends that nurturance is at the expense of autonomy."