“The Guinness Book of World Records” has called Muhammad Ali “The Most Written About Human Being Who Ever Lived,” having surpassed, in order, Lincoln, Christ and Napoleon. (This was before People and Entertainment Weekly discovered Leonardo DiCaprio.) For all those oceans of ink, though, it’s remarkable how little of genuine and lasting interest on Ali has been preserved between covers.

Muhammad Ali is simply too big a subject for a single writer — or to put it another way, he has meant too many things to too many people for one writer to reflect them all. So it shouldn’t come as a surprise that now, as Ali settles into an early Parkinson’s disease-induced old age, we have the best book ever about him, “The Muhammad Ali Reader.” The writers here include A.J. Liebling, Tom Wolfe, George Plimpton, Jackie Robinson, Murray Kempton, Norman Mailer, Garry Wills, Hunter S. Thompson, Ishmael Reed and Nigerian poet Wole Soyinka, to name just a few. Journalist and cultural critic Gerald Early pulled these pieces together, and he seems to have missed almost nothing about Ali that is of interest and even a few things that aren’t. Even the bad stuff here is interesting, if only to illustrate the range of responses Ali generated.

The first major magazine piece on Cassius Marcellus Clay was written by the greatest of all boxing writers, A.J. Liebling, in a 1962 issue of the New Yorker. Liebling had the spectacular good fortune to see the young boxer-poet get dumped on his seat by a tough journeyman named Sonny Banks. Clay was raw and unorthodox, but as Liebling wrote, “Honest effort and sterling character backed by solid instruction will carry a man a good way, but unearned natural ability has a lot to be said for it.” In the end, Liebling estimates, Clay “was the kind of Hero likely to be around for a long while.”

Two years after getting up to beat Banks, Clay won the heavyweight title by dominating the terrifying Sonny Liston so easily that writers like Nick Tosches are still conjuring up conspiracy theories about it. Overnight he became Muhammad Ali, Black Muslim and anti-war activist. Ali not only inspired great writing, he inspired great overwriting — the best, of course, coming from Norman Mailer. “He is fascinating,” wrote Mailer in “King of the Hill,” his great essay on the first Ali-Joe Frazier fight, in 1971. “The more we don’t want to think about him, the more we are obliged to … He is America’s Greatest Ego … He is the very spirit of the twentieth century.”

The downside is that Ali also inspired a tremendous amount of bad writing, and Early seems to be obliged to include some of it, such as this by Joyce Carol Oates: “When in feckless youth Ali was a dazzling figure combining, say, the brashness of Hotspur and the insouciance of Lear’s Fool …” Garry Wills, summing up the literary world’s fixation on Ali, notes that “For some reason, people don’t want fighters just to be fighters.”

He’s right. And yet, no matter how much we tell ourselves otherwise, we really don’t want Muhammad Ali to merely be a fighter. Perhaps Ali said it best himself when the Emperor told the King, “Elvis, you have to keep singin’ or die to stay big. I’m gonna be big forever.” Which means with luck, in the future, we’ll have updated, expanded editions of “The Muhammad Ali Reader.”