Many a young man is torn between gratitude and independence, between manners and honesty.

How much does he owe to those who have helped make him what he is and how much does he owe to the man he must still become?

When these familiar irreconcilables meet, should the man-child smile and say polite nothings, or should he exercise one of youth's prerogatives and tell the truth, knowing he'll probably be excused for his candor.

Moments after he had lost to Jimmy Connors, 6-1, 6-3, 6-4, in the quarterfinals of the U.S. Open today, amateur Rodney Harmon, 21, decided to opt for independence and honesty, though some will say at the expense of gratitude and manners. Connors will go on to play in Saturday's semifinals against Guillermo Vilas, who defeated Tom Gullikson, 6-2, 6-1, 6-3, at night.

Vilas needed only 1 hour 36 minutes to beat Gullikson. He ran into minor difficulty in the final set, when Gullikson broke service for the only time in the fifth game. But Vilas swept the last four games.

After his loss, Harmon will go back to Southern Methodist to ponder a gloriously successful Open performance that ended on a complex and somewhat troubling note.

In defeat, Harmon blamed what he considered his poor showing on prematch advice.

"This morning, I listened to too much advice 20 minutes before the match. I tried a whole bunch of things that are contrary to my game. I was a little confused," said Harmon at a press conference. "Finally, at 5-2 in the third set, I decided to play my own way and I started really backing him (Connors) up . . . I've learned this week always to be your own person and play your own game.

"It's time for me to be more assertive . . . It's my life and I'm going to take over . . . I felt so stupid on the court. If I'd played my (slugging) style, instead of using a lot of chips and slices, I might have lost, 6-0, 6-0, 6-0, but it would have been better."

Although Harmon never mentioned Arthur Ashe's name ("Could I leave that question alone? Just say it was a former player."), the scene spoke for itself. Harmon looked nervously and apologetically at Ashe, the man in the tennis world to whom he may owe the most, who stood 20 feet away.

Ashe is from Richmond and was the first major black figure in men's tennis. Harmon is also from Richmond, though he has learned much of his tennis in Washington, and he's black, too. If there'd been no Arthur Ashe, it's hard to conceive that the 6-foot-3 1/2 Harmon, a big, fast all-around athlete, would have settled on tennis as his sport.

In addition, Ashe has kept an eye on Harmon for years. The same group of Richmond professionals who helped sponsor Ashe's early career have, along with Ashe's financial help, aided Harmon, including paying his college tuition for a year.

Harmon knows what he owes to Ashe, and to Dennis Ralston, the SMU coach and former world-class player who gave him some impromptu coaching on strategy this morning.

A player at Harmon's level--promising for the future but barely visible at present -- couldn't buy Ashe's expertise, or the concern that has drawn the former Wimbledon and U.S. Open champion to courtside at every Harmon match of this tournament. After all, who better in all the world to coach a youngster on how to beat Connors than Ashe, the fellow who invented the chip-and-slice method of beating him in the 1975 Wimbledon final; almost every defeat of Connors' subsequent career has followed the pattern Ashe diagramed on Centre Court.

However, Harmon also knows, as Ashe knew 15 years ago, that he's the one who must trade shots with legends like Connors, not some coach in the stands. Big-time athletes don't have the luxury of maturing at a calm pace. A 21-year-old in tennis, in this era of Borgs, Lendls and McEnroes, may be approaching midcareer, and, before 30, he'll probably be at or near the end.

Ashe said he was not hurt in the least by Harmon's public comments and even added that Harmon might well have tried too hard to hit junk, when all he actually intended was that Harmon change paces occasionally from his power game.

"I was 21 once and thought I knew it all," said Ashe, quickly catching himself and adding, "Not that Rodney thinks he knows it all. He's an excellent learner. And he's probably learned more this week than ever before."

Those learning lessons are soul-wrenching for a rising star who must play and act so old while he is still so young.

What could be tougher than walking off the court, full of the last-set conviction that you'd just played the biggest match of your life completely backwards, and then have to face questioners from every corner of the tennis world?

After Harmon had told his tale of bad advice, he was, of course, asked point blank who he was talking about. The anger of defeat was fading, the knowledge of all he owed to Ashe and others was rising. Embarrassment, perhaps shame, plus a sense of the ridiculous swept over Harmon's expressive face. "I really forget who it was," he said, putting his hand over his face, laughing, but also troubled. "I wish I hadn't . . ."

So hard to be grateful, yet your own man, polite, yet honest. All at the same time. And all when you're so young.

So young, yet, as every athlete knows, always pressed by time, so close to being old.