BOOK REVIEW / It could be romance, it could be torture: 'Straight Sex' - Lynne Segal: Virago, 8.99 pounds

IT IS impossible to know what anyone else's sex life is like. Domineering men may become softies between the sheets; retiring women may grow predatory. So protean and complex is desire that no two encounters between the same individuals may represent the same experience.

Most attempts to explain sexuality have as a result proved absurdly reductive, as Lynne Segal demonstrates in her impressively wide-ranging examination; and she is brave to attempt to add to the genre. But she is impelled by strong personal indignation, and she insists that what we understand by heterosexuality matters to everyone.

Segal is determined to refute those feminists who have decreed that heterosexuality is bad for women because it inevitably supports and promotes patriarchy. Catharine MacKinnon, the American anti- pornography campaigner, is only one recent example: 'What looks like love and romance in the liberal view,' she has written, 'looks a lot like hatred and torture in the feminist view.'

MacKinnon and friends may be in the minority, but feminists who like sex with men have lent credence to their position by failing to shout it down. Segal sets out to provide them with arguments to do so.

En route, she ranges confidently across history and disciplines, exposing the shortcomings of theories of heterosexuality - from the suffragettes' conviction that women were passionless, sexually pure and morally superior to the Seventies feminist view that what really mattered was orgasm.

Segal endorses Freud's notion of sexuality as central to identity, and draws heavily on Foucault's ideas that sex is never entirely personal because of the shared social meanings that define it.

But she is not afraid to discard elements of both psychoanalytical and sociological readings. And she concludes that heterosexual feminists have had such trouble justifying their desires because 'dominant social discourses' stress 'the polarity of 'active' and 'passive', which roped to masculinity and femininity via the existing conception of heterosexuality, must itself be challenged if we are ever to turn around the oppressive cultural hierarchies of gender and sexuality.'

Lesbian feminists who have renounced men as a political gesture, in other words, are less radical than they think. Better, surely, to redefine heterosexuality to acknowledge men's insecurities, dependence, and frequent, pressing desire for passivity.

Men and women have always known that however feeble women's hold on power on other aspects of their lives, men can sometimes be rendered helpless by desire. It is no great secret that men are not permanently priapic, nor that they expose themselves to potential pain and embarrassment when they embark on a sexual relationship. Segal acknowledges in passing that sexual relations have in practice rarely conformed to dominant social discourses.

But she fails to draw out the point, because it's not good enough for her; she wants more than this tacit understanding of the unruliness of desire. She wants men publicly to face The Truth: 'What men want, as often as not, is to be sexually passive. What men do not want is for women (and certainly other men) to know this.'

It would be nice to be able to share Segal's optimism that excising the notion of active masculinity and passive femininity from dominant social discourses would not only improve sexual relationships, but speed equality on all fronts. But sex is so much about power games and transgression that it is difficult to think what would be left if they went. That said, this is a clever and provoking book, with much to agree with.