IF, as the novelist Joyce Carol Oates once wrote, “boxing has become America’s tragic theater,” then one might cast Mike Tyson — the former world heavyweight champion and self-professed “baddest man on the planet” — as the leading man. Yes, against all odds, Mr. Tyson is still alive. A pudgy 41-year-old who is millions of dollars in debt to the Internal Revenue Service, he has been living in the Las Vegas suburbs for about three months. And he is sober — 15 months now, he says — after years of drug and alcohol abuse. But this was not an envisioned outcome just a few years ago. In Mr. Tyson’s own words, “I never thought I’d live to this age.” Now that he’s here, he finds himself on an unlikely and unpleasant path forward, although one that could prove cathartic. This week Mr. Tyson and his new advisers will fly to the south of France for the Cannes Film Festival, where a new documentary about his life, “Tyson,” will make its premiere. Directed by James Toback, the film, which interposes interviews of Mr. Tyson conducted last year while he was in rehab, with fight clips, has forced Mr. Tyson to relive and reconsider a life that shames him. “I look at it now, and I’m embarrassed I did it,” he said in a recent interview. “There’s a lot of information people didn’t need to know.” But exposing Mr. Tyson’s embattled and seemingly impossible relationship with his former self is central to new plans to reintroduce the former heavyweight. The film, along with a memoir that is still in its early stages — Mr. Tyson is collaborating with the author Larry Sloman, who has ghostwritten autobiographies for Howard Stern and Anthony Kiedis, the lead singer of the Red Hot Chili Peppers — are two parts of an effort that Mr. Tyson’s advisers hope will reintroduce him to the public and propel him to some semblance of a postboxing career. Mr. Toback, who also directed “The Pick-up Artist” and “Two Girls and a Guy,” said he believed that the documentary, which is expected to be released in theaters this fall, would allow people to see the former fighter, known for his bursts of viciousness in the ring and a well-publicized rape conviction, in a more sympathetic context. “I just showed it to Warren and Annette, and it’s the first time I’ve ever seen him choke up over a movie,” Mr. Toback said in a telephone interview. “Her too.” (That would be Mr. Beatty and Ms. Bening.) Still, Mr. Tyson seems ambivalent about being in the public eye again, partly because it raises questions that he himself can’t answer. “I don’t know who I am,” he said in an interview in his Las Vegas home, one of the few extensive interviews he’s given in the last few years. “That might sound stupid. I really have no idea. All my life I’ve been drinking and drugging and partying, and all of a sudden this comes to a stop.” He speaks in his familiar high-pitch voice with a trace of a lisp, but there is no menace as he frames his past as a series of mistakes. It is easy, sitting next to him as he speaks softly and contritely, to forget how feared he was. But does the public have any appetite left for Mr. Tyson? Muhammad Ali, an Olympic hero with political cachet, has been feted in his postboxing life. Mr. Tyson, on the other hand, has been (unfairly perhaps) dismissed as a mere fighting machine. Certainly there is very little that seems threatening about Mr. Tyson on this day. Not when he exits a black S.U.V. to greet a visitor in his driveway and trudges across a pathway over a rolling stream — the only noticeable nod to decadence in this home. Not when he is handed a submarine sandwich from a member of his now-small entourage and plops on the couch, the familiar bowler hat tilted sideways on his bald, tattooed head. It was 22 years ago on a Saturday night at the Las Vegas Hilton, 16 miles from here, when the left hook from a 20-year-old Brooklyn kid full of fury landed on the temple of Trevor Berbick at 2:35 in the second round. “The day I won the title I got so drunk and high,” he said, lighting up a miniature cigar. This was the point of demarcation in Mr. Tyson’s life because what had come before was poetic: 13-year-old black kid from the ghetto streets is taken in by Cus D’Amato, a legendary fight man in upstate New York who turns him into the heavyweight champion of the world. But what came after was vulgar: Bengal tigers in the backyard, prison and bankruptcy. It is well-trod territory that is covered in the documentary, but with a sober Mr. Tyson reflecting on his foibles. During the interview he becomes enamored with a program on E! about celebrities in rehab. He is quick to recognize his friends. “I love addicts,” he said, nodding to the television screen. “I love these guys. That’s the people I want to be around. You know, former users. And I think that’s really crazy.” He said he was born an addict and doesn’t blame his affliction on the trajectory of his life. He disdains talking about his own boxing career. Other than the man sitting on the couch there is no sign that the home is inhabited by the former heavyweight champ: no trophies, no pictures, no memorabilia. “I don’t need to remember that,” he said. But Mr. Tyson showed he was still enraptured with boxing history, a love borne from watching old fight films at the home of his mentor, Mr. D’Amato in Catskill, N.Y., as a teenager. Mention one of the old-time boxers and he will launch into a monologue: “Gene Tunney, Jack Johnson, Jack Dempsey, look at those guys,” he said. “In the end they say Gene Tunney became an alcoholic, but he married well, he did well. He was erudite.” The group of people Mr. Tyson is surrounded by now is an important part of the latest chapter in his story. Don King, the flamboyant fight promoter whom Mr. Tyson accused of bilking him out of millions of dollars, is long gone. The key people now are Harlan Werner, 40, who has worked with Muhammad Ali on licensing and marketing since he was 19, and Damon Bingham, who is Mr. Ali’s godson and the son of the photographer Howard Bingham, Mr. Ali’s best friend. Both Mr. Werner and Mr. Bingham were heavily involved in the documentary, and both have producer credits. As for Mr. Toback, he met Mr. Tyson met in 1985 on the set of “The Pick-up Artist” at the American Museum of Natural History in Manhattan. Mr. Tyson, not yet the champion, had been brought to the set to meet Robert Downey Jr., and “somehow the subject got on to madness,” Mr. Toback said. “I told him about an LSD experience I had as a sophomore at Harvard. We talked about losing the self, and the difference between dread and fear.” Since that meeting, Mr. Toback cast Mr. Tyson in two of his previous films — “Black and White” in 1999 and “When Will I Be Loved” in 2004. At the end of the newest film — which was shot last year in a rented Beverly Hills home and on the beach in Malibu while Mr. Tyson got day passes from the Wonderland Center — Mr. Tyson “was talking about that empty void,” Mr. Toback said. It was something Mr. Tyson reflected on deeply when he was doing prison time in the 1990s for a rape conviction, according to Mr. Toback, who said Mr. Tyson had spent long hours in solitary confinement reading works of great philosophers. His favorites these days are Machiavelli and Tolstoy. “Cool guys,” Mr. Tyson said. “All these guys, for some bizarre reason, all these guys are in some bizarre pain. Machiavelli just wanted power. He wanted power and control. His whole game was about manipulation. “Tolstoy was all about helping the poor. He was a Communist, while his wife was a capitalist. And they had big fights over this.” As Mr. Tyson flits from philosophy to addiction to the burdens of celebrity, his ease in moving across this catholic range of interests is less surprising the more time you spend in his presence. During his time at Wonderland, Mr. Tyson’s book project was also hatched. David Vigliano, the New York literary agent, visited him there, and the two agreed to work together. But neither project — film nor movie — has been easy for Mr. Tyson. “That’s very painful stuff.” He said of his past: “I didn’t know how to be any other way. I felt like one of those barbarian kings just coming to conquer the Roman Empire. I was crazy.” Much of what Mr. Werner and Mr. Bingham are doing is trying to clean up that past. They have had to deploy lawyers to stop the selling of unlicensed products on the Internet, and there are still ongoing negotiations with the I.R.S. over back taxes. (Mr. Tyson, who reportedly earned $300 million to $400 million during his boxing career, filed for bankruptcy protection in 2003.) “We have a job to do,” said Mr. Werner, who added that he has comic book and video-game deals in the works. “We’ve got to make the guy money. That’s our job. Our plan is to do high-profile projects and associate with companies who understand that this guy has generated billions around the world in ticket sales, pay-per-view and DVD sales.” “The obvious challenge, in addition to Mike not wanting to be a sellout, is there’s the past legal issues,” Mr. Werner said. “There are times we don’t get a return phone call.” But in his prime Mr. Tyson’s name was gold. “Those pay-per-view events were some of the biggest pay-per-view events in history,” said Matthew Blank, the chief executive of Showtime, which showed several of Mr. Tyson’s fights. “The ups and downs of Tyson were extreme. Mike brought a huge amount of drama both in the ring and out of the ring.” Several months before Mr. Tyson captured the heavyweight title in 1986 he was visited in Catskill by a reporter for The Globe and Mail of Toronto who was looking to profile, in the words of Sports Illustrated, “the next great heavyweight.” At 19, Mr. Tyson told the Canadian reporter, his life goals were “peace of mind, a lot of money and to be a well-respected person.” Most of the money is long gone, but the longer he remains clean and sober the other two seem achievable. “I just say I’m not getting high today,” he said. “I’m not promising them I’m not getting high tomorrow. I’m trying to figure it out. I’m in an abysmal world trying to figure it out.”