"Are you really black and Jewish?" a fellow Yalie once asked Rebecca Walker. "How can that be possible?" She didn't answer him, but the question was one she had been asking her whole life: "Am I possible?"

Her mother, writer Alice Walker, and her father, Jewish civil rights lawyer Mel Levanthal, certainly must have thought so when they posed for their wedding portrait in 1967, in defiance of Mississippi's miscegenation laws. Didn't their "shiny, outlaw love," as their daughter calls it, herald the racial harmony we all knew was just around the corner? Wasn't racial animosity, after all, just a giant misunderstanding that could be remedied by the "clean application of Law," as Mel Levanthal believed, or through the "magic ability of words to redefine and create subjectivity," as per Alice Walker?

History, of course, proved such idealism a bit premature. Racial differences, like marriage itself, turned out to be more complicated. With the rise of black nationalism, Mr. Levanthal was recast almost overnight as an interloper by the very people for whose rights he had fought. Ms. Walker left her husband's arms to embrace feminism and eventual Color Purple fame. While Ms. Walker made San Francisco her home, Mr. Levanthal ended up in lily-white Larchmont, N.Y. , married to the nice Jewish girl his parents had preferred all along. These new worlds barely intersected. Except for one small matter: a "copper-colored" daughter.

"The only problem, of course, is me," Rebecca Walker writes (always in the present tense), describing her parents' union and breakup in Black, White and Jewish. After black and white have retreated to their own comfort zones, "I no longer make sense. I am a remnant, a throwaway, a painful reminder of a happier and more optimistic but ultimately unsustainable time."

That, of course, could be the lament of many a child of divorce-race is only part of the story here. In this lyrical and devastatingly honest memoir, Rebecca Walker bravely shares the details of childhood agonies associated with mixed heritage. There's her Jewish great-grandmother's stony silence; there's her black uncle who described her laugh as "cracker." But how much of Rebecca's personal pain came from being crushed between two (or perhaps three) estranged cultures? How to separate the racial wheat from the general human emotional chaff? How much can be blamed on those other usual suspects: adolescent angst, cultural ennui and that ubiquitous American devil, bad parenting?

Rebecca Levanthal Walker (nee Rebecca Grant Levanthal) was in the third grade in Brooklyn when her parents separated. When Alice Walker moved to San Francisco, "where she feels she can write better because she can see the sky," Alice and Mel decided on a joint custody agreement: They shuttled their young daughter back and forth between the East and West coasts every two years.

What were they thinking? "I don't know how they come up with that number, two, as opposed to one, or why they didn't simply put me in junior high here and high school there," Rebecca writes with admirable restraint. "I don't know if staying in one city so that I wouldn't have to spend my life zigzagging the country, so that I could have some semblance of a normal relationship with friends and family members, ever crossed either of my parents' minds."

Trapped in a destructive cycle, needing to re-invent herself every couple of years (and having had little clue as to who she was in the first place), Rebecca found she belonged simultaneously to two worlds and to none. Not surprisingly, some of the adjustments she made took on a racial twist: Denying part of herself each time she shuffled from city to city, from Jewish to black, from status-quo middle class to radical-artist bohe-mian, she trained herself to keep the code, not to say anything too white when she was with friends from the inner city, not to say anything too black when she was at Jewish summer camp.

But mostly Rebecca Walker's story, as she tells it, is about raising herself. Her mother bragged in interviews that she and her daughter were like sisters, but as Rebecca points out, "being my mother's sister doesn't allow me to be her daughter." So while Alice Walker was off on speaking engagements, sometimes for days on end, her "sister" Rebecca was choosing her own high school, taking drugs, having sex and generally fending for herself. When, at 14, Rebecca told her mother she was pregnant, Alice Walker arranged for an abortion. "She doesn't lecture me, she doesn't say, How did this happen, aren't you using birth control, she doesn't say much of any thing, except to call her boyfriend a few hours later and tell him .... I hear her sighing as she speaks, the same sigh I hear when she worries about money, when she's feeling overwhelmed and retreats to her bedroom for hours, sometimes days," Rebecca writes.

When it was Rebecca's father's turn to parent, he didn't do much better. He and stepmother Judy, whom Rebecca guiltily called "Mom," had little or no idea about Rebecca's complicated life. Perhaps afraid of the answers, they didn't ask any questions. "They don't ask if I'm having sex or giving blow jobs or feeling safe," writes Rebecca. When she was in 12th grade, she legally changed her name to Walker, a name that "links me tangibly and forever with blackness." Her father, "oblivious to my reality," suggested her choice had something to do with anti-Semitism.

To judge from Rebecca's account, Alice Walker and Mel Levanthal stumbled into an irony of their own making. They were certain that understanding across racial lines was possible, but as parents they failed to realize that their daughter's unique racial experiences effectively placed her in a "race" to which neither of them belonged.

Rebecca survived. Though she doesn't write much about her present life, we learn in passing that she works as a political activist in the San Francisco Bay area, and that she's gay. She makes it clear that she has found her own way at last. When her female companion, who is black, asks her if she considers black people her people, Rebecca Walker responds with impressive clarity: How can she feel fully identified with any one group of people when she has other people, too, who are not included in that grouping?

Black, White and Jewish should make Rebecca's parents squirm, but it's hardly a Mommy and Daddy Dearest. el and Alice are no different from legions of other baby-boomer parents who have mixed a high degree of self-absorption with an even higher degree of creative idealism. Even when parents fall short of their own ideals, they can still manage to pass something of value on to their children. Despite all their parental bumblings, Alice and Mel gave their daughter the tools she needed to work her way out of all this confusion, not the least important of which was love.