Lessing's latest novel is ironically at odds with her essays

The Fifth Child, by Doris Lessing. New York: Alfred A. Knopf. 133 pp. $16.95. This novel reads as if it had been poured white-hot onto the printed page. The narrative has the swift inevitability of a fairy tale, yet Doris Lessing's power of description adds to it the rough, grainy texture of a realism that could stand beside Zola's. Spare, hard-edged, stark as a parable carved in stone, it demands interpretation.

Harriet and David meet at an office party in the late 1960s. They strike their contemporaries as timid, conservative, old-fashioned. But they are not so much timid as stubborn people, uninfluenced by fads. They strike each other as ideal. They know what they want: marriage, a home, a large family, and they set about realizing their goals.

Despite the mild misgivings of his relatives and the occasional grumblings of hers, the Lovatts' endeavor seems a remarkable, even exemplary, success. Their bustling, happy household is the center of family gatherings. ``This is what everyone wants, really,'' says Harriet, ``but we've been brainwashed out of it.'' Harriet and David maintain that life can be wonderful, if only you make the right choices, as they have.

Then Harriet becomes pregnant again. This one is different, even in the womb: a fierce, incredibly powerful creature, who even as a fetus frightens and exhausts his mother. Given the name Ben, he single-handedly transforms a loving household into a living nightmare. He receives no joy from his mother's attempts to cuddle him. He takes a cold, triumphant pleasure in having his way.

In the course of the narrative, he is variously called a goblin, a monster, a mutant, a throwback. And in interviews, Lessing has (unwisely, I think) suggested she actually believes in goblins. Unwise, because its slight hints of superstition and folklore tend to weaken the novel, making it seem just another horror story, like ``Rosemary's Baby.'' What is so horrible about Ben is precisely that he is ordinary flesh and blood, but devoid of the milk of human kindness.

Massively selfish, utterly lacking in sympathy for other living creatures, the fifth child has an effect on his family so corrosive that he must be cast out of the nest - but not before he has destroyed it. The larger society is just as unequipped to deal with him. Only on the very fringes of society does he begin to ``fit in'' - in a subculture of criminality whose effect on society is almost as corrosive as Ben's original effect on his family.

But like many modern parables, its symbolism teases the reader. Perhaps it ultimately boils down to the mystery of evil. Yet the questions it raises are timely and not at all vague.

Is Ben a representative of that harsh world outside the cozy confines of middleclass domesticity? Or does he embody a more radical kind of evil, not caused by society, not remediable by its institutions? Certainly, there is an irony in the fact that Lessing's recent book of nonfiction essays, ``Prisons We Choose to Live Inside'' (Perennial Library/Harper & Row), expresses hope and confidence that the most intractable problems of the human condition may be attacked by applying the insights of social science, while her novel presents an intractable problem that defies all efforts - especially those of the social sciences - to solve it.

In the end, ``The Fifth Child'' will survive all the questions raised by many rereadings. Doris Lessing has given us a novel with a life of its own.

Merle Rubin reviews books regularly for the Monitor.