Norman Mailer was at Bobby Kennedy’s wake in 1968 when he lit a woman’s hair on fire with a candle.

It was an accident, but that didn’t count for much when the woman’s hair started to sizzle and Mailer and his friend Jimmy Breslin started pounding her over the head in an attempt to put out the flame.

“Hundreds of people were looking,” Mr. Breslin said. “Looking at the two drunks beating up the poor woman. They were thinking, ‘Look at them, the drunks. All the rumors are true.’”

Mr. Breslin, the legendary columnist and author, sounded exasperated as he told this story on Monday afternoon.

“People don’t understand the fact that Norman was a lovely gentleman!” he shouted. “They think he was some crazed creature of the night! He wasn’t. There wasn’t that much of that stuff. The whole thing was sitting and writing.”

Mailer was 84 when he died at Mt. Sinai Hospital on Saturday morning. Before that he lived a big, loud life, which he spent asking questions, accumulating bruises and setting all kinds of people’s hair on fire.

In July 1963, he had a piece published in Esquire called “Some Children of the Goddess,” in which he said exactly what he thought of his American contemporaries in the literary world. John Updike reminded him of “stale garlic,” he wrote, and William Styron was a “fat spoiled rich boy.” James Baldwin was trash and J.D. Salinger was, too. Mailer was better, was the basic idea. He was the champ. Fittingly, around this time, the illustrator David Levine did a drawing in which Mailer was dressed as a boxer, his little body in a crouch and his gloves at his face.

According to the journalist Gay Talese, one of Mailer’s closest friends at the time of his death, Mailer was proud of this drawing, and he had Mr. Levine’s original sketch mounted on cardboard. One day, Mailer packed the drawing carefully in tissue and brought it to New Jersey so he could show it to his friend, the Puerto Rican prizefighter José Torres. Mr. Torres had just finished working out and was lying in bed when Mailer walked into his room and handed him the drawing. A few people were in there talking, Mr. Talese among them.

“Look at this,” Mailer said.

“Torres took this David Levine thing from Mailer and he looked at it and he said nothing,” Mr. Talese said in an interview. “And then what he did, José Torres, he was holding it with both hands, and he looked at Mailer, and he starts to bend the goddamn thing … bending it back and forth and back and forth as if he’s gonna snap it. And he’s looking at Mailer, waiting for Mailer to say, ‘Don’t do that!’”

Mailer looked stunned but he stared intently back, according to Mr. Talese, as Mr. Torres searched his face for fear: “He was toying with him, looking for some sign of Mailer’s trepidation. … It looked to me as though Mailer didn’t know what to do. This wasn’t Gore Vidal! He was really facing down a fighter.”

It was funny, Mr. Talese said, to see the fearsome, fearless Norman Mailer so dumbstruck in the presence of true might. And so it was a relief for everyone when Mr. Torres broke the gaze, flashed his friend a broad smile and handed him his drawing back.

That’s how a lot of Mailer stories seem to go: open with blood lust, peak somewhere in the neighborhood of confrontation and end tenderly with a giggle or a wink.

Mr. Talese has another story like that. This one takes place in early fall 1962, when he and Mailer were both in Chicago to cover the historic Sonny Liston vs. Floyd Patterson fight at Comiskey Park.

The night before the big match, Mailer participated in a debate against National Review editor William F. Buckley, an event billed as a showdown between “a conservative and a hipster” about the nature of the right in America. Thousands of people came to watch, and Mr. Talese wrote an article about it for The New York Times.

In his piece, Mr. Talese called the Mailer-Buckley face-off a draw, and he didn’t think much of it after he filed his report.

The following evening, Mr. Talese was sitting in a hotel talking to some sportswriters over drinks. He saw Mailer walking toward him from across the room.

“He’s looking at me and he’s getting closer and closer and he’s not smiling,” Mr. Talese recalled. “And he’s just looking at me, staring at me. And then he comes over and says, ‘What the fuck do you mean, “draw”? I looked at his face and thought, This guy is serious!”

That was when Mr. Talese, who was wearing a tan summer suit made of either gabardine or silk—he doesn’t remember which—noticed that Mailer was carrying a drink, from the looks of it some kind of whiskey or bourbon. Mr. Talese knew as soon as he saw it that this drink would end up on his clothes if he did not do something immediately to defuse the situation.

“I remember thinking, I’m in trouble here. Because if he throws a drink at me, first of all my suit’s going to be ruined with this bastard; second of all, it’s going to be a scene,” Mr. Talese said. “I looked at him and I felt suddenly that I had to stop that drink from coming at me. … I just felt like, I can’t let this happen—it’s going to be humiliating for me. Here’s this lunatic writer, this brilliant fuckup of a guy, this kamikaze, this loose cannon called Norman Mailer, and I looked at him as though I was fucking Don Corleone … and I just said, ‘Norman Mailer, do not throw that drink at me.’”

This made Mailer smile and laugh. “I wasn’t gonna throw a drink at you!” he said. “I just wish you hadn’t said it was a draw.”

And that was the end of it. Just as it had to be, really, because for all that famous recklessness and brutality, Mailer’s pugnacity was playful, more an expression of his stylistic sensibility than a genuine threat to the people around him.

Mailer wasn’t really a fighter at heart, in other words. But he liked playing one because it forced him to test his limits.

Sometimes this ended badly for him. Ringside at Cotto vs. Mosley at Madison Square Garden this past Saturday night, legendary boxing writer and filmmaker Budd Schulberg recalled that Mailer once pulled a head butt on the dean of British sports journalism, Hugh McIlvanney, who retaliated by decking him handily in the jaw.

“Norman went rolling back onto a table of food,” Mr. Schulberg said. “It was a huge mess.”

According to author Sidney Offit, who served on the board of the PEN American Center when Mailer was president of the organization during 1984-1986, that sort of thing only happened when Mailer was around a lot of people. If you got him on his own, Mr. Offit said, he was usually quite gentle and calm.

“He was an absolutely endearing and engaging and supportive friend, one on one, but by the time five people were there, he was making speeches and startling everybody,” Mr. Offit said. “By the time eight people were there he was juggling and swallowing swords and doing a high-wire act.”

Indeed, Mailer was a bold and dedicated performer. Never was that clearer than in 1971, when at age 48 Mailer put on shorts and gloves and got into the ring with Mr. Torres on the set of The Dick Cavett Show. According to Mr. Breslin, Mailer threw all his punches with his eyes closed.

Mailer didn’t care who saw him lose, and that was just as true in his writing as it was in his life. He hid nothing from anyone, letting the whole world watch as he grappled tumultuously with his unwieldy curiosities about evil, God, power, sex and consciousness.

“He was willing to take large risks and make himself look silly,” said novelist William Kennedy, who was a close friend of Mailer’s at the time of his death. “And these large risks were very imaginative leaps into the unknown. He made something out of his fanciful ideas and that was the direction he was always trying to go in, which was to do something that had never been done before.”

A mad scientist who wasn’t afraid to experiment on himself, Mailer did so publicly with gusto and muscle and never worried about looking ridiculous if there was something he really wanted to try.

And so he tried to do a lot of things, like follow his best-selling debut novel The Naked and the Dead with a book about an anti-Stalinist libertarian-anarchist from Brooklyn. And run for mayor of New York City in 1969 (with Mr. Breslin as his running mate) because he thought New York City should secede from the state. And write a book from the perspective of Marilyn Monroe. And make movies and direct plays even though he didn’t really know how. And help start a new weekly newspaper in New York because he thought the dailies were not doing their jobs.

There was often nothing glamorous or graceful in Mailer’s efforts, and though his failures were never out of plain sight, he was never discouraged from tackling his next project with seriousness and imagination. In effect he stood before his critics naked, fundamentally vulnerable despite all his machismo and arrogance.

In so doing he practiced a singular approach to intellectual inquiry—a form of New Journalism more radical and more ambitious than anyone else had dared to try. Whereas Tom Wolfe and Truman Capote had simply applied the mechanical conventions of fiction to the telling of true stories, Mailer went further, all but becoming a fictional character in his own right and hurling himself against the world he was trying to figure out to spectacular, revelatory effect.

“His brain was so big compared to what we were used to in journalism,” Mr. Kennedy said. “He just brought a consciousness of the cosmos to whatever he was writing on. … You didn’t think of what he was doing as just a fictional device or something to bring structural or stylistic newness to a story. He was bringing a mind, and his mind was so fertile and his language was so rich and evocative and provocative, it just made for spectacular reading.”