• Fiction. By Doris Lessing. HarperCollins, $25.95.Grade: C+

Plot in a nutshell: At 88, Lessing has published an important and controversial body of work. In this latest novel, she again presents a radical idea - this time, about the birth and evolution of mankind and the differentiation of the sexes.

The book starts as a Roman senator gathers disturbing oral and written records of a prehistoric "tribe" in an attempt to clarify mankind's roots. In this past, the Cleft was a rock where sacrifices took place. The women of the tribe, named after the landmark because of similar physical characteristics, live a life of indolence by the sea. There are no men. The Clefts give birth magically, impregnated poetically "by a fertilizing wind," and only to females until, mysteriously, "Monsters" begin to be born, babies deformed with appendages and bumps that are totally alien to existing life.

Lessing uses the appearance of males as a means of exploring the origination and cultivation of language and social structures. The discovery of intercourse and the inevitable results are amusing but repetitive, and the narrative begins to circle back on itself until it becomes almost farcical.

Part of the problem is that Lessing is trying to make myth when she can only make fiction. Every step of the way, her choices are forced, whereas in myth, the direction is organic, derived from inherent fears in nature. Although the effort is commendable, the story cannot work to dispel what we believe about biology, sociology or religion.

Sample of prose: "But soon they were not young females, but founders of families, clans, tribes - and at some point, ages later, evolved into goddesses."

Pros: When it works, the book touches on elemental truths about nature, language, religion and, of course, sex.

Cons: When it doesn't work, it becomes a parody of itself, as in this: "People were remembering old myths: surely things had been better when males had not been needed to make children."

Final word: The presentation of primordial male/female personality stereotypes becomes awkward, and although there are passages of courageous writing, the overall effect is confused and not a little naive.