What is the worst thing that has ever happened to humankind?

History is long and frequently awful, but a war that consumed 60 million people and added "Hiroshima," "Nagasaki" and "Auschwitz" to the world's vocabulary surely stands apart.

And suddenly it was over. Suddenly Japan was a democracy. Japan was free. Japan was no longer "feudal."

When a nightmare ends you get on with your life — what else can you do? — and yet the sheer speed of Japan's return to normality, even making allowances for the psychic wounds that never heal, is bewildering, though partly explicable in terms of American aid and the Korean War boom — thanks to which, as historian Richard Storry observes, "By 1950 the shattered cities were almost, if not quite completely, rebuilt in a rough-and-ready sort of way. "By 1953," he adds, "personal income in terms of purchasing power had been restored to the prewar level."

More astonishing still is the transition from "feudalism," "militarism" and everything bad to "freedom," "democracy" and everything good. Children see things adults don't, and we have the testimony of the hero of the novel "A Boy Called H," a fictionalized war memoir by Kappa Senoh. "H" (for Hajime) is a teenager when the war ends. A closet liberal like his dad, H is happy to hear from his teachers as the Occupation begins, "You must not look on the Americans as enemies anymore." Yet something about the budding peace stinks in his nostrils: "There were quite a few phonies among the teachers at school. ... It made him feel sick to see a man who'd been militarism incarnate until the day the war ended, behaving as though he'd always been a champion of democracy, all the while preserving his customary magisterial air. H was disgusted by this hypocritical display of hastily borrowed democracy."

H's parents, though not H himself, are Hiroshima natives, and H at home in Kobe reads a newspaper report of "a new type of bomb" that concludes, "The Land of the Gods will never be brought low by a mere bomb!"

Masuji Ibuse's 1966 novel "Black Rain" is a guided tour of bombed Hiroshima: "The mound of corpses was black with swarming flies." All of Japan was. There must have been many survivors who envied the dead. Shigematsu, Ibuse's protagonist, in his dazed wanderings around the destroyed city, encounters a blackened corpse that seems to be moving: "I approached the corpse in fear and trembling — to find swarms of maggots tumbling from the mouth and nose and crowding in the eye sockets; it was nothing but their wriggling, that first impression of life and movement."

If a nation could commit suicide out of sheer despair, Japan, with its culture of honorable and glorious suicide, might have done it. We know what happened instead. In Jiro Osaragi's novel "Homecoming," published in 1948, a suave young man entertaining a lady in a nightclub deplores the somber turn the conversation has taken: "I hate people who insist on talking about the war at this late date."

The war was over, the past was past, the dead were dead. Why dwell on all that — on Ibuse's flies and maggots — when such a bright future beckoned? There was freedom to be seized, money to be made, good times to be had. In another novel of the early postwar period, Shishi Bunroku's "School of Freedom," a teenage girl rebelling against an arranged marriage sums up the new outlook on life with the English phrase (only an English phrase could do a new outlook justice) "I don't care" — about anything, except following her whims and inclinations wherever they might lead. Arranged marriages are "feudal"; she will have none of hers. Her name is Yuri. Takabumi, her intended husband, feels the same way; the two are, in fact, best friends, urging each other on in their respective love affairs. Takabumi pursues an older (30ish) woman named Komako; Yuri is after Komako's estranged husband.

"You were born in a good age," Komako tells Yuri.

Yuri shrugs. "Not especially. From now on we have to fight for what we want — all kinds of things." What is she stressing as troublesome — the fighting, or the insatiable wanting?

Meanwhile, Takabumi and Komako's husband have a little encounter: "Takabumi greeted Iosuke warmly, doffing his hat to reveal his fashionable Ginza haircut. For a young man to greet someone whose wife he had been courting and with whom his fiancee had been cavorting, without a trace of resentment or hostility, would have been unthinkable before the war."

"Young man," says Iosuke, "is it true you're in love with my wife?"

Perfectly unruffled, Takabumi replies: "We young people don't believe love is absolute. With that limitation, I can say yes, I do love her."

The novel begins with Komako, brisk and efficient, throwing the slothful Iosuke out of the house. They part with mutual relief. Freedom! Komako, brimming with ability, ideas and energy, dreams of the self-realization the new order seems to promise. Iosuke dreams of liberation from Komako, but his first night of penniless homelessness brings him up short: "This search for freedom was not going to be easy!"

But he adapts. All of Japan was adapting — to one thing if not to another. Born into a prosperous commercial family, Iosuke sinks with beguiling grace into bottomless indigence, feasting with relish on a "postwar goulash" made from scraps extracted from garbage cans at the dormitories used by the Occupation forces and quite agreeing with his mentor, a veteran scrounger who observes, "Shouldn't the Japanese consider themselves lucky to be occupied by a people with such largesse?" Yes indeed, thinks Iosuke, washing the greasy mess down with cheap liquor called a "bomb."

In Ibuse's "Black Rain," a doctor dying in agony of what would soon be known as radiation sickness expresses his will to live in these terms: "I decided I'd rather die ... of some proper disease that I could account for." He survived. So did Japan. But it was close.

Michael Hoffman's new book, "In the Land of the Kami: A Journey into the Hearts of Japan," is out now.