The Postman <i> by David Brin (Bantam: $15.95; 294 pp.) </i>

“The Postman� is set in a post-holocaust North America in the early 21st Century. Government, technology and organized society, as we know them today, are gone, victims of successive cataclysms of war, riots, looting and environmental disasters. What remains is an atomized society much like that of the early Middle Ages: isolated settlements, dependent upon a primitive agricultural economy, conducting little trade beyond barter transactions, and remembering only fragments of the earlier civilization. Native survivalists, hyper- macho paramilitary bands that follow the teachings of an Ayn Rand/Soldier of Fortune prophet named Holn, are the Vikings and Tatars of this new Dark Age, pillaging at will, enslaving women as concubines and gelding men as serfs.

The central character, Gordon Krantz, an outsider from the East, reflects on the motivations and foibles of those he meets, and against all odds remembers and understands the lost world of 20th-Century America. In the course of his pilgrimage West to Oregon, he discovers a dead postman whose uniform and sacks of mail are intact. Krantz appropriates the uniform for warmth, and in his first encounters wearing the uniform he discovers that lies about a putative “Restored U.S.� come easily. As the narrator reminds us, “The people believe, and that’s what counts.�

Krantz begins a tentative mail service, recruits others to join his efforts, and soon almost believes his own lies, as he majestically gives orders on the authority of his self-appointed rank as postal inspector and general federal agent. His fame spreads with his travels, and he confronts other efforts to deal with the chaos of a post-holocaust world: the Oz-like reincarnation of a defunct super-computer, neo-feminists trying to adapt Lysistrata to the war against the survivalists, a pacifist guru, and finally, the officers of the Holnist army, led by a general who is a survivor of pre-holocaust experiments in the creation of “augments,� Venice Beach muscle men of Rambo-like strength and endurance.

Krantz is a fleshed-out character, with qualms about his appropriated role as postman and his involvement in violent adventures. The other characters are categories: neo-feminists, neo-hippies, a black ex-Marine. The survivalists are pure villains of the sort who used to be portrayed tying a maiden down on the railroad tracks. And while many of the evils the marauders and survivalists visit upon the innocent in the book are sexual or physical, there is an odd queasiness in the narrative, a reluctance to describe or even mention the atrocities, which produces sentences like “The corpses had not been left unmarked.�

Much of the explication of the post-holocaust world is seamlessly woven into the narrative; it is almost in passing that we learn about the electromagnetic pulse that destroyed all electronics, and the segue to a comment on the breakdown of the interdependent machine culture is artful. Elsewhere, the explication is squeezed into dialogue, and we’re not sure whether it is a character or the author who is telling us, for example, that pre-holocaust Americans “loved to accuse themselves of terrible crimes as a people: a strange practice until you understood that its hidden purpose was to make themselves better. . . .�

The world Brin draws is terrifying; the metaphor of the postman and his lie is thought-provoking. I only wish the book weren’t marred by the conventions of science fiction, which seem intrusive or naive in a novel set so close to our present world. Thus Krantz’s internal monologues are presented in italics, as if readers couldn’t be expected to identify his thoughts, and there is too much material from what the pre-holocaust world called Western Civ I, tossed out as though it were a novelty. David Brin’s provocative story needs neither.