Unwonderfully What She Was : KATHERINE MANSFIELD A Secret Life <i> by Claire Tomalin (Alfred A. Knopf: $22.95; 292 pp.) </i>

Only a passionately self-absorbed actress like Meryl Streep or Diane Keaton could do justice to a film of the writer Katherine Mansfield’s life when inevitably, alas, it will be made. Only a Streep or a Keaton would be equal to Mansfield’s exquisitely neurotic mixture of melodramatic posing, reckless ambition (without quite the talent to match), self-destructive bisexuality and sheer bloody malice. It is a considerable compliment to Claire Tomalin’s coolly balanced biography that she keeps us wondering right to the end at Mansfield’s untimely death what exactly fascinated her contemporaries about this transplanted New Zealander who crashed London literary society only to be destroyed by it.

Today, Mansfield’s reputation rests on a small body of short stories, one or two little gems such as “The Garden Party” and “Bliss,” and a darkly sexual myth partly, perhaps mainly, created by her literary Frankenstein and husband, John Middleton Murry. As Tomalin points out, Murry could hardly wait to boil the bones, “puffing and promoting” her stories posthumously just as in life he had foolishly encouraged her “to think that she was somehow a genius simply by ‘being wonderfully what you are.’ ” Wonderful Mansfield was not. Early on, Tomalin warns us, “Hatred was her favorite emotion.” She was also a pathological liar, a domestic trouble-maker on a truly operatic scale, envious, small-minded and profoundly cruel. She delighted in degrading her lifelong friend and “wife,” the aptly named Ida Constance Baker, to the status of a badly treated servant. She tended to despise those whom she was not temporarily in love with.

Reading Tomalin’s level-headed biography, which sees its subject as some kind of trail-breaking heroine because she rebelled so strenuously against male-forged chains of convention, an impatient reader may be tempted to wash his hands of Mansfield and her set, which included both Bloomsbury (Virginia Woolf, Lytton Strachey, etc.) and the D. H. Lawrences.

The literary intellectuals of Edwardian England were often a ridiculous lot, loudly carrying on about “Love” and “Friendship” in capital letters while fumbling grotesquely with their personal lives. The Lawrences and Mansfield and her husband desperately sought tenderness and inspiration from one another while helplessly and sometimes cheerfully stabbing their beloved ones in the back. (If for no other reason, Mansfield should be remembered as the model of the cynical feminist “Gudrun” in Lawrence’s novel “Women in Love.”) But there is also something comically heroic about their efforts to put flesh and blood on what were then subversive ideas, such as women’s suffrage, marriage reform and sometimes stupid, sometimes brave, attempts at sexual self-knowledge.

Tomalin’s book only partly convinces me that there was something more to Mansfield than her reptilian nature. She’d had the bad luck to contract gonorrhea, with all its horrid complications, and TB, (possibly from Lawrence) which enfeebled much of her life. At the same time, her best stories were written in a kind of a fever toward the end. Her worst luck was in choosing a husband on whom she was hopelessly dependent, but for whom she felt contempt, and who repaid her with a most subtle revenge: exalting her reputation after death beyond what even she would have claimed for it. I think Tomalin is suggesting a feminist tragedy here. Maybe. If so, the ultimate restitution will be in our returning not to Mansfield’s life but to her work, which at its best had a splendid, malicious pathos.