Lives Unfold Along Two Trains of Reality : THE DYLANIST, <i> by Brian Morton,</i> HarperCollins, $19.95, 312 pages

As with any serious, wonderful work of literature, “The Dylanist” is difficult to paraphrase.

Brian Morton has written a story about two kinds of reality: the “history train,” the public life that chugs along and sometimes picks us up and sometimes doesn’t, and private life, our “family,” whatever that is, and how individually we’re supposed to live as human beings.

Sally and Daniel are son and daughter to two “old Lefties,” former devoted Communists in the ‘30s and ‘40s. Hannah, their sweet mom, warns them as kids not to mention the word Communist outside the house.

She wistfully misses her own youth, which she remembers as idealistic, full of picnics and folk songs, and the sense of doing good , trying to change the world. “We didn’t leave the Party,” Hannah says at one point, “the Party left us.” But Burke--Sally’s father, Hannah’s husband--stays on the History Train another way.

He becomes a dedicated union organizer, itinerant, intent on organizing the working class that doesn’t want to be organized very much. Burke knows he’s doing good, but how much “good” is he doing, really? Meanwhile, Hannah teaches first grade and becomes an activist for open classrooms and the rights of children.

A family, then, with “progressive,” “leftist” values. The kind of family that--when Barry Goldwater runs against Lyndon Johnson--thinks of moving to Canada if Goldwater wins. (Then, Johnson wins, and starts bombing the socks off Southeast Asia.)

Sally, through whose eyes this story is seen, learns early on that there are nice people, and then there are a lot more of the other kind, and the other kind are in charge. Born in 1957, she grows up getting stoned, collecting a few good friends, loving her brother and her parents, and wondering what it means to be alive, what her rightful place in the world may be.

What does it mean to “grow up?” The first half of “The Dylanist” very quietly and tenderly paints a picture of enclosed family life. Daniel, Sally’s older brother, smokes a little too much grass and doesn’t have quite the college career he might have.

Sally drifts through college, finds Owen, a second-choice sort of guy whom she lives with for awhile. Then, absently, she begins to teach kindergarten and first grade.

But, wow! In a virtuoso fictional display of karm-uppance, everything that has gone around begins to come around.

By the time Sally is 26, one of her girlfriends has had a couple of kids. Another is committed to law school and hooked up with a capitalist geek. (A wonderful scene comes out of this.) Ronald Reagan is running the history choo-choo train, and “the common good” is the last thing anybody seems to be thinking about.

Time speeds up. The family, in another set of intensely realized scenes, goes through a cancer scare. (Who of us has not gone through those agonizing days, hours?) A parent is going to die. Everyone in the family knows it. The time becomes both precious and agonizing.

Meanwhile, Sally has met a chunky guy at a party, a union man who’s tough, but devastatingly naive. He actually believes you must try to improve the world, even if you’re doomed to fail.

And he recognizes Sally as a “Dylanist,” a stubborn devotee of Bob Dylan, a girl/woman loyal only to the authenticity of her own feelings. . . .

How hard it is to write about a wonderful book where nothing “happens” except precious life. All I can say is: This is one to buy, to read. It echoes in the brain, as your own life unfolds.

Next: Constance Casey reviews “Mercy” by Andrea Dworkin (Four Walls, Eight Windows).