Sex Takes a Meander : TALK DIRTY TO ME, <i> By Sallie Tisdale (Doubleday: $22.95; 338 pp.)</i>

In “Talk Dirty to Me,” Sally Tisdale has not attempted to write, as the title may suggest, a turgid novel riddled with heaving, pulsating organs. Not at all. Tisdale has attempted instead a high-minded yet passionate study of human sexuality. Her aim is to debunk sexist and repressive thinking, to examine and celebrate gender roles in all their myriad glory, and then to strip away assumptions and facades and get right down to the real truth about sex.

She has failed.

I had a feeling she might when I read in the first chapter, “This book, even when it’s about other people’s fantasies and other people’s myths, is largely about me . . . my concerns, my interests, my own little fetishes, as it were.”

It’s not the egotism that worried me. All writers write about themselves, even the driest scientists are writing about what interests their very own brains. The trick is to write about the part of the self that we all have in common, the self riddled with vast insecurities and existential Angst , the self that searches for any sort of universal truth it can get, not the self that worries if she can make it to the dry cleaner before her dental appointment and what’s that jiggling sound behind the steering wheel?

What worried me is how ham-fisted Sally Tisdale’s brain must be if she feels she must spell this out for us. Why this urgent need to confess what we already know?

Oh boy. The woman muses. She daydreams, pontificates, speculates and drools. But what she does best is meander. She’s like a basset hound taking a stroll. She stops and sniffs every tree, she finds a fascinating bit of chewing gum in the gutter, she stops and licks herself for a while, then sees something in the distance that might be a rabbit, might be a falling leaf and rushes after it pell-mell.

With this amorphous structure, even a book about sexual fantasies, orgasms, masturbation and prostitutes is tedious. Especially since Tisdale writes almost entirely in generalities. Here she is on porno films: “Women I know say they feel uncomfortable watching their lover turn on to another woman’s image, even as they turn on to the image of the man in the same film.”

What women? What film? Uncomfortable how?

Reading this book, I started craving something concrete, some telling detail. At one point Tisdale relates a story about going into a store and talking to a clerk about her small purse. By this time I was so deprived of lively specifics I became positively excited. But no, the story had no middle, no end, it just turned into a rumination on how her small purse makes Tisdale feel unfeminine.

It’s a pity. Tisdale is not the enemy. She is well-meaning, open-minded and generous. She wants us all to follow our sexual fantasies wherever they may lead, as long as they don’t hurt us or anyone else. She wants us to realize that our sexuality is at the very core of our beings and not something that should fill us with shame and contempt.

Well, duh.