Ron Lyle is one of 10 boxers interviewed in Pete McCormack’s terrific “Facing Ali.”

“Choose your enemies carefully, ‘cause they will define you,” the adage goes. Muhammad Ali doesn’t have a lot of enemies anymore — 28 years after his last professional fight, and 25 after he was diagnosed with Parkinson’s disease, he remains among the most beloved figures in American public life.

It was a different story back in 1967, when he was stripped of his championship belt, sentenced to a five-year prison term, and banned from boxing for declining to be inducted into the Army. If joining the Nation of Islam and changing his name from Cassius Clay three years earlier had caused much of white (and some of black) America to view him with suspicion, his refusal to “go 10,000 miles from home and drop bombs and bullets on brown people” made him a full-blown pariah in some quarters. More importantly, it made him a hero in others. Forty years on, it’s pretty clear which impression has stuck.