“The social organization which is most true of itself to the artist is the boy gang,” Allen Ginsberg once observed. It’s a sentiment that Frank Sinatra would have appreciated. The time of “Howl” and “On the Road” was also the time of “Frank Sinatra Sings for Only the Lonely” and the original “Ocean’s Eleven,” and although by many measures a taste for the product of North Beach is incompatible with a taste for the product of Las Vegas, the Beat Movement writers and the Rat Pack entertainers were shapers of a similar sensibility.

When “On the Road” came out, in September, 1957, it was praised in the New York Times as the novel of the Beat Generation, equivalent in stature and significance to “The Sun Also Rises,” the novel of the Lost Generation. The book was a best-seller, and it made Jack Kerouac, who had worked on it for ten years, a celebrity. It is sometimes said of Kerouac that fame killed him—that he was driven crazy by being continually addressed as the spokesman for a generation and by endless unwelcome requests to explain the meaning of the term “Beat.” Kerouac was certainly undone by something. After the success of “On the Road,” he continued to write at a manic pace, as he always had, but he became a suicidal alcoholic, and he died, of a hemorrhage caused by acute liver damage, in 1969, at the age of forty-seven. (He had by then written more than twenty-five books.) The notion of the Beat Generation was hardly thrust upon him, though.

“Beat” is old carny slang. According to Beat Movement legend (and it is a movement with a deep inventory of legend), Ginsberg and Kerouac picked it up from a character named Herbert Huncke, a gay street hustler and drug addict from Chicago who began hanging around Times Square in 1939 (and who introduced William Burroughs to heroin, an important cultural moment). The term has nothing to do with music; it names the condition of being beaten down, poor, exhausted, at the bottom of the world. (It’s used often in this sense in “On the Road.”) In 1948, Kerouac is supposed to have remarked, in a conversation with the writer John Clellon Holmes, “You know, this is really a beat generation” (followed by a spooky “only the Shadow knows” laugh), and Holmes thought enough of the phrase to use it as the working title of a novel, eventually published as “Go,” and to write an article for the Times Magazine, in 1952, called “This Is the Beat Generation,” in which he credited Kerouac with the term. (The article was solicited by the man who, five years later, wrote the Times’ review of “On the Road,” Gilbert Millstein.)

Holmes wasn’t referring to a movement. He was referring to the Cold War generation, which, he said, had been disillusioned by the war, the bomb, and the “cold peace,” but was obsessed with the question of how life should be lived. Holmes thought that Beats were optimists, risk-takers, seekers—young people with “a desperate craving for belief.” The article popularized the concept, and Kerouac began using it himself. “Beat Generation” was one of his early titles for “On the Road.” (Another was “Shades of the Prison House.”) After the book came out, he wrote a play called “Beat Generation,” an article for Esquire on “The Philosophy of the Beat Generation,” and another for Playboy on “The Origins of the Beat Generation,” in which he added “beatific” to the meanings of “Beat.” In interviews up to the end of his life, he talked about his conception of the Beat Generation, and the literary movement associated with it, proudly, affectionately, and defensively. In his final appearance on television, a falling-down-drunk performance on William F. Buckley’s “Firing Line,” he insisted that his idea of beatness had nothing to do with the hippies (whom he despised).

It’s true that the Beat writers were caricatured and abused. In the literary world, academic critics, whose aesthetic was all about form and restraint, ignored them, and the New York intellectuals, whose ethic was all about complexity and responsibility, attacked them. Irony was the highbrow virtue of the day, and the Beats had none. This response probably did matter a little to Ginsberg and Kerouac. They were Columbia boys. They had genuine literary aspirations, and they wanted to be taken seriously. On the other hand, they could hardly have lived in hope of the approval of people like Diana Trilling and Norman Podhoretz.

In the entertainment world, “Beat” was transmuted into “beatnik,” a word invented, in 1958, by the San Francisco Chronicle columnist Herb Caen. The term derives from Sputnik, which was launched into space a month after the publication of “On the Road.” (Why is a beatnik like Sputnik? They are both far-out.) The type was made immortal by the character Maynard G. Krebs on the television series “The Many Loves of Dobie Gillis”—a goateed, bongo-playing slacker who calls people “daddy-o.” But lampooning is merely the price of mass attention.

Satire and polemic are, on some level, defensive. It’s possible that something about the Beats simply made people uncomfortable. For the nineteen-fifties images of the Beat—Partisan Review’s bohemian nihilist and Hollywood’s hip hedonist—are almost complete inversions of the character types represented in “On the Road.” The book is not about hipsters looking for kicks, or about subversives and nonconformists, rebels without a cause who point the way for the radicals of the nineteen-sixties. And the book is not an anti-intellectual celebration of spontaneity or an artifact of literary primitivism. It’s a sad and somewhat self-consciously lyrical story about loneliness, insecurity, and failure. It’s also a story about guys who want to be with other guys.

The Beat Movement had a male muse. This was, of course, Neal Cassady, the protagonist of both “On the Road,” where he is Dean Moriarty, and “Howl,” where he is “N. C., secret hero of these poems, cocksman and Adonis of Denver.” Cassady also figures in several of Kerouac’s other books—five of Kerouac’s road novels are being published this fall by the Library of America ($35) in a volume edited by Douglas Brinkley—and his iconic presence went beyond the Beats. He became a friend of Ken Kesey, and he was the driver on the Merry Pranksters’ famous bus trip, the subject of Tom Wolfe’s “The Electric Kool-Aid Acid Test.” The Grateful Dead wrote a song about him. He is the Lou Andreas-Salomé, the Alma Mahler Gropius Werfel, of postwar American culture.

Cassady was an uncanny cross between James Dean and W. C. Fields—a screwup with a profile, a stud with an endless supply of goofy gab. There is sufficient testimony concerning his sexual endowment to overcome the skepticism normally advisable on that topic. Some people who knew and liked him called him a con man (and many people, including Burroughs, disliked and avoided him), but this seems misleading. Cassady was a serial seducer, and, therefore, inveterately untrustworthy. He grew up on the Denver streets—his father was a wino—and he learned to cope by relying on his enormous energy, adaptive wit, and good looks. He charmed people in order to get what he needed, and he was generally in need of something. On the other hand, the people he charmed generally needed something from him—sex or companionship or good times. And Cassady had no material ambitions. He was content to get by, and although he had three wives in rapid succession, and juggled his attentions between them and assorted casual girlfriends, he was intermittently serious about all of them. Everything about Cassady was intermittent. He had a kind of sociosexual A.D.D.