<i> The Good Terrorist</i> by Doris Lessing (Knopf: $16.95; 375 pp.)

Doris Lessing, born of British parents in Persia (now Iran), reared in Rhodesia (now Zimbabwe), and a resident of London since 1949, is a writer who understands the world of violence and change. “Looking around the world now, there isn’t a way of living anywhere that doesn’t change and dissolve like clouds you watch,” she wrote in a 1972 preface to her collected African stories.

Lessing has persistently spoken for undergrounds and subcultures. She’s like a wise and visionary matriarch who urges patience and lucidity on a family that’s divided. In subject matter, she ranges widely, from colonial oppression (“This Was the Old Chief’s Country”) to her most recent works, the five novels she refers to as “space fiction,” which attempt to present human history as an episode in cosmic times (“Canopus in Argos”).

With her new novel, “The Good Terrorist,” Lessing has returned to the conventional form to explore one of her most persistent themes, which is the difficulty of acting with individual conscience. Many of our problems, she suggests, stem from the fact that people are pressed into conformity.

A group of young people with radical political views are squatting in an abandoned house in London. As revolutionaries, their aims are rather ill-defined: They belong to a group called the Communist Centre Union. (“Think of it as the British Communist Party,” someone in the novel says, an organization that Lessing herself joined in 1952, and left in 1956.)

At the center of the radical commune is Alice Mellings, in her mid-30s, and her boyfriend, Jasper. Alice, a caring and kindly person, wears pretty little floral blouses beneath her combat jacket and attends to the needs of the comrades like a mother. She is the good terrorist of the title. Jasper, however, is so cruel that you wonder why she stays with him. He forces her to move her sleeping bag to the wall opposite him because he can’t stand her near him and twists her arm when she doesn’t do his bidding. The reader quickly realizes that Alice lives in a masochistic dream world where the self is denied and a sadistic thug like Jasper is worshiped in the name of the revolution.

Gradually the group attracts recruits: two lesbian feminists, one of whom suffers bouts of mental illness; a black unemployed printer; a pallid decorator whose girlfriend has thrown him out; a middle-class couple who choose to squat in order to save money, and a woman who builds bombs in the attic. All agree that the system is rotten and must be brought down. But where to begin? The search for an appropriate target for their radicalism fuels the story.

While the others attend marches and man picket lines, Alice sets about transforming the squatter’s habitat, with its pails of excrement filling up unused rooms, into something livable. In other words, middle-class values of cleanliness, order, industry and thrift reassert themselves. House repairs are costly, however, and throughout the book runs Alice’s plaintive chant: “We must have money! I have to get more money,” which she does by stealing from her divorced parents.

The need to prove themselves as true terrorists (“the real thing,” as Alice is fond of saying) causes Jasper and another comrade to journey to Ireland where they offer their services to the IRA, and when they are rudely rejected, to travel to Moscow and approach the KGB, which also turns them away. The rejections make them murderous with rage. It’s a terrible thing to burn with revolutionary fervor and have the revolution reject you as though you were an unworthy petitioner to a country club, or an applicant for a credit card. They are driven to act. A bomb is constructed, a target is chosen, and the tragedy that they’ve been moving inexorably toward occurs.

The novel is a brilliant account of the types of individuals who commit terrorist acts, but it’s about much more than terrorism in the world. It’s about how patterns of behavior wear different rhetorical cloaks but remain little changed underneath. When Alice arranges a convention of the Communist Centre Union, for instance, it differs very little from the sorts of parties her mother was so good at giving.

Toward the end of the book there’s an important exchange between Alice and her mother, who due to Alice’s thievery and selfishness, is living a stripped-bare life in a bed-sitting room in a shabby section of London. She tells Alice that all her dreams for her, the money spent to educate her in order that she have a better life, have come to nothing. Alice has spent her life exactly as she did, “cooking and nannying for other people. An all-purpose female drudge.” She goes on: “This world is run by people who know how to do things. They know how things work. They are equipped. Up there, there’s a layer of people who run everything. But we--we’re just peasants. We don’t understand what’s going on, and we can’t do anything.”

Lessing has given us a quintessential good woman, Alice Mellings, the little Hausefrau revolutionary. But her goodness is suborned by the collective and she commits evil, for surely it is evil to blow up randomly selected people with car bombs.

Lessing is one of our most valuable writers. She has an uncanny grasp of human relationships. She cares very deeply about what happens in the world. (She has suggested that one result of having been a Communist was that it made her a humanist.) Now, one senses, she is just dead-tired of politics. And yet, regardless of whether politics have served her well, she continues to honor political questions with a graceful and accomplished story such as “The Good Terrorist,” which is ultimately as benevolent as it is intelligent and revealing.