I’ve long savored a definition of the sentimentalist from James Joyce’s Ulysses, but I've only recently come to see how it applies to sentimentalists like me who follow and chronicle professional boxing.

Actually, the last part of that sentence ought to be in the past tense.

Though I've written a history of boxing trainers as well as a novel set in the boxing world, I will not be one of the millions paying just south of $90 to watch Floyd Mayweather and Manny Pacquiao square off in Las Vegas on May 2 in what reportedly will be the most lucrative boxing match in history.

But back to James Joyce. In Ulysses, Stephen Dedalus says, “The sentimentalist is he who would enjoy without incurring the immense debtorship for a thing done."

Joyce scholars tell us that Stephen cribbed the epigram from the British author George Meredith. But to me, it’s a good definition of anyone who has enjoyed a boxing match, myself included. Because most of the men—and it’s almost always men—who watch a prize fight never incur the “debtorship of the thing done.” Those of us on the sidelines—writers, promoters, and other devotees of the sport—don’t risk having our lives shortened by what Martin Amis has called, “the only human pursuit dedicated to the infliction of head injuries.”

Yes, boxing is different than other sports. It’s worse. Recent headlines reveal the long-term side effects of the repeated concussions sustained by football players in a sport where head trauma is a side effect of the competition. But in boxing, neurological damage is the goal.

When one cheers for a knockout, after all, one is cheering for a concussion—and the long-term damage it causes. A neurologist friend explained it this way: Every time a boxer receives a blow to the head, brain cells are damaged and blood vessels can be ripped, causing hemorrhage. The body scrambles to repair the damage and restore the integrity of the brain’s circuitry. But after successive blows, the brain cannot keep up with the necessary repair work. But each time a fighter loses consciousness, lasting damage is done.

Just look at Muhammad Ali. These days, of course, Ali rarely appears in public, and when he does, he doesn’t speak.

Like many boxers before him, Ali suffers from Parkinson’s disease. This is one of the pugilistically induced illnesses that one finds in the obituaries of former fighters. Another is Alzheimer’s, which contributed to the untimely deaths of Sugar Ray Robinson and Floyd Patterson and lord knows how many other former champions. Manny Pacquiao’s own trainer, the former boxer Freddie Roach, suffers from Parkinson’s disease.

In the world of professional boxing, the fighters are the exploited class. There are exceptions to this rule, of course. Some boxers hang onto their health, their sanity, and their money. But more often they come to very bad ends.

Consider the following: three-time world champion Alexis Argüello, a suicide at the age of 57; five-time champion Johnny Tapia, dead of a drug overdose at 45; two-time champion Arturo Gatti, 37, found hanged in a Brazilian hotel room; three-time champion Hector “Macho” Camacho, shot dead during a botched drug deal at age 50. Then there are the countless stories of former champions and contenders living in poverty because the millions they’ve earned in the ring have been squandered or stolen by hangers on or the unscrupulous—if not criminal—promoters who abound in the largely unregulated boxing world.

Yes, there is beauty and art in boxing. And yes, Ali in the ring possessed a species of improvisatory genius. No one has written about this dark art better than Norman Mailer. When I was growing up, Mailer’s boxing writing gave me license to follow the sport: he made boxing an intellectually acceptable vice.

Mailer summed up his defense of boxing in The Big Empty, a book of conversations with his son John Buffalo published in 2007: “Boxing demands … a certain courage of the blood that goes very deep. It’s what attracts us to boxing… What would a lot of these kids do if they weren’t professional boxing and couldn’t make a living out of it? The answer is that a lot of them would be likely to lead violent lives. You know, when people have a little more violence in them than the average, their lives take on all sorts of very difficult turns.”

I agree with Mailer. Boxing can be redemptive, and it’s done a world of good for plenty of young men. I’ve heard many versions of the story that goes something like, “Without boxing, I’d be running on the streets or taking drugs or getting into all kinds of trouble.” And I’ve met boxers and trainers who are gentle and wise, comfortable with their own masculinity in ways that elude many men in more refined pursuits.

And yet. I don’t know how you can feel good about yourself after an evening of watching other men inflict enduring neurological damage on one another other for money.

If you watch a fight on TV, you don’t quite understand what’s happening because technology distances the viewer from the action, rendering the violence abstract. But when you sit up close at a live boxing match, you see it all: the blood, the dazed eyes, the quivering limbs. You see that to root for one fighter over another is to deny the humanity of the man you want to see lying unconsciousness on the canvas.

I’m mortified that it’s taken me this long to come to the obvious conclusion.

Joyce Carol Oates has written that boxing is “America’s tragic theater.” Maybe so. Maybe boxing fans watch in pity and terror as a battered fighter suffers a fate that we ourselves dreaded in school yards decades ago. Yet unlike a true tragedy, a boxing match offers no catharsis.

And those of us in the cheering, jeering crowd are sentimentalists: we have enjoyed without incurring the immense debtorship for a thing done.