The flood of tributes that have been pouring in for Mr Muhammad Ali since early yesterday morning is testimony to the iconic status of the American who declared himself the world’s greatest boxer and proved it with not only his ring craft, but his phenomenal ability to promote the sport.

People familiar with boxing history will tell you that when the brash 22-year-old Cassius Marcellus Clay entered the sport as a professional, very few pundits gave him a chance of lifting the heavyweight title from Mr Sonny Liston.

But in that February 1964 fight, the youngster, who had generated world attention by winning gold in the light-heavyweight division in the Olympics held in Rome in 1960, “shook up the world”, as he put it, by defeating Mr Liston. Thus started one of the sport’s most colourful and exciting careers that ran for two decades with 56 wins, from 61 fights — 37 by knockout — and saw him becoming the first boxer to win a world heavyweight title on three separate occasions — 1964, 1974, and 1978.

But while the world marvelled at his talent, it is obvious that his strong opposition to his country’s involvement in the Vietnam War and his refusal to be drafted into the American army in 1967 contributed in large measure to the respect he gained globally.

That decision cost Mr Ali three-and-a-half years of his career at a time when he was in his prime, as he was stripped of his boxing licence and sentenced to prison. However, he was not incarcerated after he filed an appeal.

In time, Mr Ali’s principled, unwavering anti-war stance became a rallying chord for an overwhelming movement in the United States and the wider world against what was increasingly perceived as unjustified military aggression by the world’s most powerful nation.

Hence, United States President Barack Obama’s description of Mr Ali as a towering champion “who fought for what was right”.

“His fight outside the ring would cost him his title and his public standing,” President Obama said. “It would earn him enemies on the left and the right, make him reviled, and nearly send him to jail. But Ali stood his ground and his victory helped us get used to the America we recognise today.”

That, we believe, is the true measure of the man who was designed Sportsman of the Century by Sports Illustrated and Sports Personality of the Century by the British Broadcasting Corporation.

In 2005, as well, Mr Ali was presented with the United States’s two highest civilian awards — the Presidential Citizens Medal and the Presidential Medal of Freedom — for “exemplary services” to his country.

Despite his skill, Mr Ali suffered from an affliction common to boxers — the inability to quit while they are ahead. It was painful to watch him being beaten by his former sparring partner Mr Larry Holmes in Las Vegas in 1980.

It took a loss to Mr Trevor Berbick, in December 1981, for Mr Ali, then 40 years old, to finally throw in the towel.

However, in the context of history, those mishaps at the end of Mr Ali’s career are mere blips. He will be remembered not only as arguably the greatest sportsman of the 20th century, but for being among the most influential, game-changing human beings of our time.