Great pain leaves great damage. The injuries of a lifetime can conspire like spies to set us against ourselves. What seems to be obvious self-defense can be sly destruction.

The story of Mac O'Grady, born Phillip McGleno, should be joyous. It may yet end that way. But, at the moment, an inspirational golf saga is turning ugly and sad.

At the very moment O'Grady should be taking bows for becoming one of the better golfers in the world, he seems bent on damaging or ruining his career with a succession of attacks on PGA Tour Commissioner Deane Beman and others.

Saturday, O'Grady was fined $2,000 for "conduct unbecoming a professional golfer" -- primarily his six-month-long string of blasts at the integrity of Beman, whom he called "a thief," a "totalitarian" and dozens of other insults.

O'Grady said Saturday he would "rot in hell" before he'd ever pay a cent. On Sunday, O'Grady told me, "I'm takin' 'em all on. Next they'll try to suspend me. Just watch. They better be real careful now. I'll take them to court and sue them for millions . . . Golf needs a congressional investigation . . . I'll never give in to them . . . If I have to die, I will die."

Yesterday, Beman informed O'Grady of his "preliminary decision to impose a major fine [$5,000 to $10,000] and a suspension from tournament play of three to six events and to place you on probation for one year."

If any story ever needed background for perspective, this one does.

O'Grady is a hard-knocks eccentric who failed PGA qualifying school 17 times over 11 tormenting years before reaching the tour at age 32 in 1983. He was broke, bummed out and bounced around so much he changed his name to change his luck. "I spent 10 years on a Greyhound bus. I've played so many places around the world that being on tour is like Christmas every day. My nose was pressed against the candy store window for years. Now I'm inside."

And eating his fill. The thwarted kid who ran marathons, practiced yoga and played golf ambidextrously -- all, he says, to calm the demons of frustration in him -- has become a star. "I have moved from the prodigy stage to virtuoso," said O'Grady, who plays right-handed, putts left-handed. "Now I want to stay there." He's marched from 120th on the money list to 20th in 1985 -- $223,808.

As O'Grady left the last hole at the Doral Open on Sunday, he signed every autograph request and stood patiently for five minutes as a father coaxed a recalcitrant 2-year-old into golfing a ball with a midget club.

O'Grady gave his shocked caddie a $500 tip (on top of the customary 10 percent cut of his $19,000 fifth-place check). "Thank you. You're the greatest," stammered the caddie. Then, O'Grady, who often won't talk to the press, gave a reporter an hour-long interview.

That's one side of O'Grady. Smart, gifted, generous, patient, idealistic. The other side, however, is deeply scarred.

"The reason I'm mad is that when I was 20 I was victimized by 10 or 15 [personal] sponsors. I was exiled, blackballed out of southern California," he said. "They did everything to mutilate me. Wherever I went to try to raise money to play golf, they always got the word out and stopped me . . . changed my name. Phillip McGleno is dead . . . It took a year for my ex-sponsors to find out, but they did . . . I'm not going to say I'm living for revenge, but if I'd gotten the money I needed I'd have made it years ago."

The idea of injustice is the fuse that lights O'Grady's dynamite keg. If he thinks he's been wronged, the old wounds become fresh. In 1984, Beman fined O'Grady $500 for calling a woman scorekeeper "a bitch" and "a little Hitler." That's when our cheery plot line changed. For two years now, O'Grady has been on a bitter crusade.

"The issue isn't the $500, it's the principle of the thing," said O'Grady, who carries a thick file with him on his case against Beman. He'll only talk to reporters as a pretext "to blast Beman every chance I get."

Said O'Grady, "I told Deane, 'You think I'm a PGA member before I'm a citizen of the United States? . . . Why, when I can tell the president of the United States I disagree with his policies, can't I turn around and say anything derogatory about the tour?' "

O'Grady may have a point there. He knows it and, no matter how high the cost, he may be unable to let it go.

Some day a court may well decide O'Grady is correct. In 1969, when the pro tour broke away from the PGA of America, the players voted to institute a strict code of conduct. "The players thought it would be good for the game and good for business," said Beman.

But is it constitutional?

The PGA Tour muzzle on speech and behavior is one of the game's embarrassments. Beman telling Tom Weiskopf or Craig Stadler to shave a beard is ludicrous. Fining a player for saying that "putting over Riviera's greens was like putting over a waffle iron" is, too.

O'Grady, frustrated by the golf "system" for so long, has reached the point where tilting at windmills may have become irresistible. The golf scene has so many sacred cows to poke, so many loose threads to unravel, that he is constantly tempted to provoke authority.

Some of what O'Grady says is acute. He raises sharp critical points about the PGA Tour's absence of health insurance and its rules that you must play in pro-ams to collect a pension.

"I level about everything," O'Grady said. "Have you seen the movie 'Mr. Smith Goes to Washington'? That's me. They can't keep me quiet . . . The American public will like what I have to say."

Beman and the golf tour can stand having their feathers and their regulations ruffled. The real victim won't be Beman's authority or the feelings of tournament sponsors.

What's scary is where O'Grady is headed.