It was bound to happen.

Just when Plato's Retreat and the pleasure principle are playing in Peoria, the news is out from California -- trend central -- that sex is out. O-U-T, out.

Celibacy, which used to be out, for everyone but monks, nuns, Shakers, men recovering from hernia operations and teen-agers with terminal acne, is in.

Don't laugh. According to author Gabrielle Brown, celibacy is the only sane reaction to the sexual revolution of the last two decades: the one-night stands, the group gropes, the wife-swapping, bed-hopping frenzy of orgasmic pursuit.

"The physical activity of sex has become America's dominant social activity," the author writes. "And even if you are not participating in every sexual opportunity that comes your way, you are at least supposed to be fascinated by its availability."

Spurred on by recent newspaper and magazine articles naming members of the new celibate chic (Andy Warhol, Mick Jagger, Jerry Brown and New York mayor Ed Koch), the author manages to fill 192 pages (plus index) with historical fact, psycho-sexual babble and smug testimonials from the newly celibate.

"The best way to tell if you might be ready to celibate for some time," Gabrielle Brown advises, "is if it feels natural." In other words, if it feels good -- don't do it.

There are, of course, several things to be said in favor of celibacy. It does eliminate the need for birth control. Not to mention hot tubs, computer dating, post-coital cigarettes and Frederick's of Hollywood. Imagine what the television networks would do if the fad really caught on: "One's Company" and "The Platonic Love Boat."

But going from one extreme to the other does not seem to offer much comfort. Perhaps the "New Celibacy" is the ultimate aftershock of the "Me Generation," not the sexual revolution, as Brown contends. In fact, the book might have been subtitled, "How to Be Your Own Best Lover."

Listen to the new celibates:

"I do enjoy the company of women a great deal," says Patrick a 61-year-old research director. "I am attracted to them and they to me. But since I'm not really wanting to pursue a sex-based relationship, I try not to make myself available."

"Being celibate has given me a new way to investigate my feelings and to appreciate myself more," says Evie, a 26-year-old dancer. "I feel a great deal more myself -- like this is who I really am."

"I feel more pure, more whole, more true to myself and much more able to love deeply," says Alexandria, a 42-year-old counselor who compared sex to the "frosting on the cake." Coincidentally, she lost 40 pounds in her first six months of celibacy.

"Sex has never provided much of an opportunity for growth in me," says Sarah, a 35-year-old professor of linquistics. "I love physical warmth and find it wonderfully nourishing . . . [but] if I lose myself, my 'center,' then I am not really enjoying the momentary experience."

Wait there's more.

"I feel stronger, more self-sufficient but also more open to loving and being loved deeply," Sarah gushes. "It's actually more sensual being celibate than being sexual. Maybe I should write 'Memoirs of the Sensual Celibate'!"

Unless it's already been written, which is extremely likely.

As for why they chose to become celibate, there seems to be a common theme: All had been sexually active, even promiscuous by some standards, before they saw the light. Several of them gave up sex after divorces; one woman said the death of her boyfriend shocked her into sexlessness, and one man said he decided to become celibate for a while after contracting venereal disease. Which is a pretty persuasive reason for swearing off.

Although apparently transcending the pleasures of the flesh to "grow as a person," to appreciate members of the opposite sex more fully, at the celibates sounded desperately unhappy in their smug, self-righteous defense of asexuality. Especially the married couples.

"Celibacy kind of lets us be spiritual together," says Diane, 28, who has not made love with her husband Tom for the last three years of their five-year marriage. "When we have sex again, we don't want it to be a downer but an act of worship."

One husband says his wife didn't become boring to him -- orgasms did. One wife says she is actually more attracted to her husband, now that they are no longer having sexual intercourse.

But for all the new-found zeal in touting celibacy as the best thing since Perrier with a twist, few of the interviewees had shared their secret with friends or family. "My parents would think it was the end of the world if they knew," says one celibate husband.

The author herself, in a "dos and don'ts" column, warns the devotees not to tell "everyone" you are celibate. "The resulting onslaught of sexual advances, no matter how subtle, will knock you out," Brown says. "The challenge is just too much for sexuality active people."

Giving up sex, she thus implies, is comparable to a schoolchild giving up Hershey bars for Lent. Once the other kids know they'll try to force-feed you.

Perhaps the most disturbing element of Brown's thesis, apart from the high-school term-paper prose, is the absence of any discussion of commitment. Sexually for most of us is the physical manifestation of human love and the need to share that experience with another.

To become obsessed with an all-consuming desire to deny that experience as a part of a chic new trend I find amusing. But not as amusing as the dedication in the front of the book. "To my parents," it says. Who, fortunately for Gabrielle Brown, were not celibate.