Sex may be a subject of infinite, uncategorizable richness, but literature about sex usually follows conventions as formalized as the Library of Congress catalog system. There's the briskly scientific (the most newsy these days being the comprehensive survey Sex in America), the hardcore pornographic, the soft-core pornographic, the seriously erotic, the humorously erotic, the romantic, the how-to, etc. All these subdivisions, though, have one thing in common: Each masks a real-life, eyes-open, when-I-do-this-I-feel-that account of what the experience of sex is like for an actual, specific person. What is there about sex that is so intimate, so fearsome, so beyond the safety net of words that even the most liberated and confessional of writers fumbles for honesty and even the most sophated of readers frowns and fidgets nervously in embarrassed response?
Sallie Tisdale, a contributing editor of Harper's magazine, attempts to answer the question in Talk Dirty to Me (Doubleday, $22.95). A sensually packaged book, it's got a silky slipcover, its cover features a seductive photo of a woman's hand proffering a tush-shaped peach, and it's subtitled ''An Intimate Philosophy of Sex.'' Organizing her linked essays like a sex act itself Desire, Arousal, Climax, and Resolution she offers herself, one specific woman in her late 30s with a husband and three kids, as a kind of sexy peach, too, inviting us to compare and contrast, to feel sex through her senses, to sample her feminist philosophy and to get beyond embarrassment by tasting what turns her on.
Lots does. ''Sex,'' Tisdale writes, in the feminine, sing-songy murmur she favors, ''is a game, a weapon, a toy, a joy, a trance, an enlightenment, a loss, a hope.'' Tisdale likes men and women (she identifies herself as bisexual). She loves watching other people in the act. She appreciates male drag, prostitutes, masturbation, pornography, people who like sadism and masochism, Whorezine (''the house organ of career prostitution''), and bonobo apes, which ''are always going at each other one way or another, and the line between sex and aggression is blurred almost as much with them as with ourselves.''
Talk Dirty is an arousing book, proudly female in its imagery and philosophy and interests, and parts of it may make a shy reader uncomfortable. (In empathy, the author refers to Richard Rhodes' confessional Making Love, a kind of male counterpart to Dirty that evoked a fidgety response among reviewers when it was published in 1992.) But you know what? Tisdale can't get beyond a certain sexual point right ... there either. She backs off from the personal just as we get really turned on (okay, just as I get really turned on). She retreats from specificity into poetry. And she spends far too much time on a unified field theory of feminist sexual philosophy that just isn't nearly as interesting as shiny, wet description.
I'm fascinated, for instance, to learn that when she was a teenager, Tisdale spent time in a therapy group based on the radical theories of Wilhelm Reich, the ''paranoid schizophrenic'' (her words) who invented the orgone box to treat ''genital frustration.'' And that ''when I was in my late twenties, my mother called to tell me, almost in passing, that the young woman who had been my best friend for several years in adolescence was now a man.'' Hot stuff! Tell me more! Tell me what effects these experiences had on Sallie Tisdale!
She doesn't. Instead, by the time Talk Dirty to Me subsides to Resolution, I retain a memory of safe statements like, ''If every man thought his penis were good enough, there wouldn't be so many phallic symbols.'' The fresher thrills of Tisdale's reaction, say, to the sounds of a woman having sex overheard on the street through a half-opened window vanish, meanwhile, like ... a climax. Maybe I'm just nervous. B+