Richard Pryor, hamming it up in a crucifixion pose for his first album’s cover shoot in 1968. (Henry Diltz)

At the end of the cultural and political tumult called the 1960s, five major African American stand-up comics were poised to achieve crossover greatness. Each, in his own way, represented a clear break with the earlier image of black crossover humor represented by the likes of Clarence Muse, Stepin Fetchit, Willie Best, Sam McDaniel and Mantan Moreland, who played obsequious and easily frightened servants and sidekicks in Hollywood films of the 1930s and ’40s. In a sense, the black comic of the ’60s was attempting two types of crossover: to bring a type of in-group, non-minstrel-tainted black humor to white audiences and to liberate black comics to do any sort of humor that suited them or that any given audience was willing to accept as funny.

First was Redd Foxx, the raunchy veteran of the chitling circuit of small black inner-city clubs and R&B revues who made it in Las Vegas, was a hit in the 1970 blaxploitation detective film “Cotton Comes to Harlem,” and landed his own successful television series, “Sanford and Son.” Next was Dick Gregory , a college track star who developed his stand-up in small black clubs before crossing over to television and New York clubs and becoming the wisecracking wit and social activist of the civil rights movement. Flip Wilson , who also honed his act in small black clubs and, like Gregory, developed his ability for stand-up while in the military, became Johnny Carson’s favorite guest host on “The Tonight Show” during the 1960s and then the first black to host a successful, long-running television variety show.

Bill Cosby was probably was the biggest black comic star to emerge from the period. A Philadelphian who began telling jokes while in the military, Cosby, unlike the others, started out in small New York clubs before mostly white audiences, eschewing race and explicit sex humor. His clean but hip act was a huge success, helping to make him the first black male actor to co-star in a network television series, “I Spy.”

Of the 1960s group, Peoria-born and -bred Richard Pryor (1940-2005) might have been the most incandescent, surely the most volatile and fragile but redoubtable black comedian of his time. Reared by his grandmother in a brothel in an atmosphere of fear, academically untalented but with an interest in performing, he stumbled into the world of black nightclubs in Peoria. Eventually, he moved to New York, where he got involved in improv and the Village scene, then became a minor success in the mid-1960s as a black comic, mostly as a high-strung imitation of Bill Cosby. Wanting to make his act more cutting-edge with profanity, more honest about race and sex, Pryor reinvented himself in stages, talking candidly, often obscenely, about race, sex and whatever else was on his mind. He was, as Cosby noted, “bringing in a new kind of language,” not just dropping f-bombs and n-bombs uncontrollably. Pryor was making black male street language funny, observant, humiliating, witty — even poignant.

He sped comet-like across the 1970s, for a time more highly regarded than any of his peers, white or black, before flaming out in the ’80s, addled by a monstrous cocaine addiction and a disastrous personal life that included wife-beating, inveterate infidelity and child neglect. He was disfigured physically and emotionally in 1980 by a self-induced fire that nearly killed him. He was exhausted by the wear and tear of trying to be funny for a living and wracked by the insecurity of his fame. Though still a box-office magnet, he seemed to be growing ever more fatigued as a performer, finally brought low in 1986 when he was diagnosed with multiple sclerosis. By the end of the decade, in films like “Harlem Nights,” his performances, afflicted by his illness, seemed nearly catatonic.

“Becoming Richard Pryor” by Scott Saul. (Harper)

Scott Saul’s “Becoming Richard Pryor,” the most detailed and rigorously researched work on the comic’s life and performances, is not a complete biography; it ends with the 1980 cocaine crackup. At this point, Saul asserts, Pryor “became the teacher from whom everyone else learned,” something for which we have to take Saul’s word. Why becoming a teacher meant that Pryor stopped “becoming” is a bit of mystery. Not doing the last 25 years of Pryor’s life simply seems arbitrary.

Saul is right that growing up in his grandmother’s brothel made Pryor both a cynic and a romantic. This contradiction — uncompromising honesty and idealistic purity, spiked by the further contradiction of militant race loyalty and a sexual obsession with white women during the racial and sexual liberation of the ’60s — made Pryor both the quintessential hipster and the vulnerable, damaged witness of his age, smashing taboos even as he acknowledged their hold on him. He was endowed not only with enormous greed, largely influenced by the blatantly greedy adults around him during his childhood, but also with a moral and social sense, an empathy with victimization, that kept warning him that greed was not enough to justify a life. This set of complexities is what made Pryor such a brilliant comic actor, as his act was the “self-sabotage” of a half-assed, self-aware, ironical sociopath. Saul’s book, though too long, captures these dimensions of the persona and the man behind it very well.

Early is a professor of English and African American studies at Washington University in St. Louis.

Comedian-actor Richard Pryor, shown as he performs in 1977, died in 2005. (AP)

By Scott Saul

Harper. 586 pp. $27.99