By Jenny Diski

Simon and Schuster. 256 pp. $16.95 Let's justgo back and pretend women's liberation never happened, if it means we can unload the likes of Rachel Kee, the "feminist" heroine of this first novel. Seriously. Give me romance novels with silly, gushing dunderheads -- they've got to be better role models than this tragically misshapen character from Jenny Diski's "Nothing Natural," a novel that dwells on the abusive affair between a sadistic man and a masochistic woman. I'd almost trade back Title IX and Supreme Court Justice Sandra Day O'Connor if I could be sure that not one reader would come away from this book believing that women (not to mention feminists) really degrade themselves and each other the way the women of this novel do.

Rachel is dangerous as a feminist heroine, but not in the way readers might expect. She's not the hardened man-hater in a pin-stripe suit who's bitter and emasculating. Instead, she's a rather low-decibel sort: small, unselfish, unmuscled and somewhat soft and lovable. Independent, in her thirties, divorced and raising her young daughter, she prides herself on her feminism, her self-reliance, her casual attitude about sex, her open-mindedness. It's that mellow strength that makes her so likable at first, and yet it all drops away too soon, as if her feminist principles were just a pair of gloves that she left on the seat of the bus. In just one night, and for just one overweight, aging man, Rachel quickly trades in her liberation for bondage.

The squalid affair begins one evening when a woman friend of Rachel's arranges a small dinner to pair the recently divorced Rachel with a man named Joshua. Before the event, the friend warns Rachel that Joshua "is not someone to get involved with, but interesting ... He really messes people up" and "he's a bit weird about women." Over dinner, Rachel plays it cool and tries to act superior. But it's the last time she acts that way. Before the night is over, Joshua takes Rachel home. In their lovemaking that first night, he shows her that he is a sadist. From that moment on, she is hooked on a sick and sadomasochistic relationship that both repels and attracts her and that strips her totally of her dignity and humanity.

Sex with Joshua becomes more abusive, more violent; she asks for more. He tortures her psychologically, leaves her in the middle of the night and calls her only when he pleases, sometimes ignoring her for months. And Rachel waits longingly by the phone. "Feminist principles or not, it turns me on," she tells another woman friend as she describes her affair with Joshua and chalks up her masochism to a kind of feminist self-exploration, as if she were doing nothing more than consciousness-raising or getting in touch with her feelings.

Maybe the relationship between Rachel and Joshua is supposed to make sense in the strange, grotesque landscape of this book. After all, Rachel is a woman whose good "friend" planned a three-course dinner to introduce her to a man whose reputation for being "weird about women" makes him a highly desirable dinner guest. And Diski has provided Rachel with an extremely troubled childhood; rejected by both her mother and father, she was then adopted by a foster mother. But Rachel has come out of that troubled background with a good strong backbone. She holds down jobs, gets married, bears a child, functions as an intelligent human being, endures a divorce and then raises a child as a single mother. Are we to believe that such a survivor is likely to surrender her being, her essence, her body and soul to a paunchy, leering sicko like Joshua? Not likely.

It's not that Diski, or any woman writer, has to carry on some sort of literary affirmative-action program, wherein all women characters are left ensconced in the board room and brimming with self-confidence. But Diski tries to make us sympathize with Rachel and yet convince us that Rachel thrives on self-hate. And we can't do both at once. Rachel doesn't seem that profoundly sick, so we like her even less for acquiescing so easily to the whims of such a domineering lout.

In some ways, this is a bold book; it takes a fair share of risks in exploring the female psyche, relationships, eroticism, the nature of love. It's a daring venture for a first novel. But if a writer expects readers to jump off the high board with her on the first time out, she should have plenty of water in the pool below. The reviewer is a senior editor of The Washington Post Magazine.