Why? said the old trainer.

Why not? said the old fighter. "He knows what he has to gain, what he has to lose, what sacrifices he has to make," Joe Frazier said about the compelling topic in boxing just now: Sugar Ray Leonard's announcement that he wants to fight Marvelous Marvin Hagler.

As we all do, the former heavyweight champion knows what drives Leonard. And never mind that he sounded, over the phone from Philadelphia, as though he were talking through a half-mouthful of oatmeal.

The force that will get Leonard back into the ring is as simple to understand as it is addictive. It's what causes dreamers to hop atop rockets; it's what kept Willie Mays in center field too long. It's why over-the-hill amateurs gravitate to obscure basketball courts at noon.

Pride. Stupid pride.

It eventually gets exorcised. A couple of trips to the emergency room usually force playground plodders into retirement. Not being able to see the fairway, let alone reach it, drives hackers back to the middle tees.

Mays, John Unitas, Frazier and now Leonard are different from the rest of us only by degree. They are superior at sport, not necessarily more consumed by it.

Leonard thinks he's better than Jack Nicklaus. Maybe he is. But Nicklaus at least worked at his trade, struggled even, before striding to the summit once more three weeks ago.

Two years into his second retirement, the only fight Leonard wants is Hagler. No tuneups. All that moves him is Hagler. Wouldn't Yaz concede he'd need more than batting practice if he chose a comeback against Dwight Gooden?

"Five weeks is all it would take," Frazier insisted. "He's not a baby. He's been around. His tuneups would come in the gym. Every day in the gym was a championship fight for me." He laughed.

" Sparring partners are the only people paid to beat you up. They want to make a reputation for themselves. That's how it was for me," in his one-fight comeback in 1981 after a four-year layoff.

Time now for the old trainer to intrude with some wisdom.

"And who was that comeback against?" asked Ray Arcel, who saw Frazier's 10-round decision over Jumbo Cummings. "Some guy who couldn't shine his shoes."

Arcel has seen all the fighters worthy of attention the last half-century and trained many of them.

Leonard's decision makes him sad.

"Just finished reading about it," he began the conversation from New York, "and I can barely talk. There's only one word I can think of: Why?

"I don't care who the fighter is -- and he was real outstanding, maybe the best of his decade -- you can't beat these layoffs. You know what to do, but you can't do it.

"Even if Hagler was not great, only good, he's still active. He's active. He's also the best around today. Why fight the best if you're not ready? If Hagler also had laid off two or three years, it might be different."

Arcel flicked Leonard's recent history through his mind: "Real tremendous . . . Left a wonderful taste with everyone who saw him. Then he retired," in 1982, after suffering a detached retina.

"Then he came back two years later against Kevin Howard and got knocked on his behind. I never dreamed I'd see a guy throw a right hand and knock him on his back.

"Time does that. Kevin Howard should not last two rounds with Sugar Ray Leonard. He should pounce on a Kevin Howard, hit him with five million punches, surround him."

To many of us, Arcel evidently included, a man only climbs into the ring so he can walk away to a better life as soon as possible.

Boxing is the coal mine of sport. You only get into it because the alternative is worse. Arguing that it is not even sport, the American Medical Association is fighting to ban boxing.

"If I was close to Sugar Ray," Arcel said, "I would tie a big rope around him, nail it to the first tree I could find and keep him there. I would discourage him in every way I could."

Arcel trained Roberto Duran for 10 years. Of a recent trip to Panama, he said: "I saw him work in the gym -- and nearly got sick, because Duran is like a son to me.

"What I'm looking at and what I used to look at . . . " He paused. Seeing Duran, thinking of Leonard, Arcel said: "It just doesn't make sense. I understand Duran. He wasted $15 million. He's desperate. There's no other way he can make it."

Here Arcel grew adamant. The old trainer who has seen so much sadness and humiliation in boxing said: "I don't care what excuses Sugar Ray gave me for a comeback . I don't care what story he brought before me.

"I would say no, with a capital N."

The only person who could say the emphatic and final "no" is Hagler. Probably, understandably, for he also has a full dose of champion's pride, Hagler will say: "Any time you want, Ray."

Arcel's realism is an unintended sucker punch at Leonard's adviser, Mike Trainer. He surely knows that you don't walk away from a friend simply because what he wants seems dumb and dangerous.

"If the doctor gives his permission," said Frazier, "why not? Hagler's a great champion, but we all make mistakes somewhere down the line. Let's see what happens."

"If he wins the title," Arcel countered, "what's he gonna do with it?"

All we know is that Leonard needs a Hagler fix. He's as hooked as all of us. Glad to see you're mortal, Ray; sorry, too. Trainer is like the wife who shakes her head at the man strapping on a knee brace as he prepares for Sunday football.

In her heart, she can't quite comprehend such folly. But she tags along anyway. If the experience happens to be exhilarating, perhaps even moving, that's fine. If fate demands hurt, she hopes it will mend quickly.