Like the moralist who philosophizes that having the right reason is as important as doing the ethical thing, Tim Gullikson has concluded that winning points in a tennis match is satisfying only if he knows he has "made the right play."

"My coach, Hank Jungle, has ingrained that in my mind. It's important to go for the right shot in a given situation, even if you miss sometimes," Gullikson, one of the rising stars in the tennis firmament, said yesterday. He beat Terry Moor, 6-3, 7-5, in the $125,000 Volvo Classic at George Washington University's Smith Center.

To illustrate his point, Cullikson - who is seeded No. 8, and plays Tony Roche in the second round today - recalled two matches he played a fortnight ago in the U.S. Indoor championships in Memphis, where he was runner-up to Jimmy Connors.

"In the squarters, I beat Bob Lutz, 6-4, in the third set, but I was mad at myself becase I didn't do the right thing. He missed his first serve on my first match point, and I knew I should run around his second serve and hit a big forehand return if I got the chance," he said.

"But I couldn't make up my mind, even when he tossed the ball. Finally, I just chipped a safe little backhand return, and he knocked off a volley for a winner.

"I finally beat him on my fourth match point, but that stuck in my mind and bothered me. The next day, against Sandy Mayer in the semis, the match came down to a similar situation. I ran around his second serve and nailed a forehand return, reverse cross-court, to end the match. God, that felt good.

"At this level, going for the right shots on the big points, when the pressure is on, separates the winners and losers," he continued. "You've got to take the gamble when the percentages favor it."

Against Moor, a left-hander who thumps his ground strokes with heavy topspin, Gullikson played aggressively, as is his wont. He is best at the net, where he can capitalize on his quickness and agility, and tried to get there as often as possible - behind his own serve and deep returns of Moor's second serve.

"He hits as hard as anybody, and with so much spin that it's tough to volley cleanly. The ball is always dipping," said Gullikson, winner of two of three previous meetings with Moor. "But I didn't want to get into many long rallies with him."

It was a peculair match. Trailing, 0-2, in the first set, Gullikson won eight of the next nine games to 2-0 in the second. But he promptly lost his advantage and was broken again to 4-5.

But with Moor two points from the set, serving at 30-all, Gullikson crackled a forehand cross-court pass on the sideline and a backhand cross-court pass to break back. He lost only two more points, holding at 30 and breaking at love, Moor double-faulting on the final point.

Tim is the right-hander of the 26-year-old tennis-playing Gulliksons of Onalaska, Wis. His identical twin, Tom, who is five minutes older, lost in the first round Tuesday to John McEnroe, 6-3, 7-6, after saving six match points in a tie breaker that went to 12-10.

The Mighty Gulliksons - Jim and wife Rosemary, and Tom, and wife Julie - have been a delightful addition to the pro tennis tour the past two years. Rosemary and Julie - sorority sisters at Northern Illinois University, where Tim and Tom (Class of 1973) were a matched pair of guards on the varsity basketball team - are often mistaken for sisters.

The twins are distinguishable to the trained eye - Tom has a gap between his front teeth, a small scar under his chin, and is five pounds lighter - but there is a growing catalogue of "mistaken identity" stories involving them.

The most famous occurred at the expense of German pro Karl Meiler, who lost to both withina three-week span. Not realizing there were two Gulliksons, he moaned about "this young American who can beat me playing with either hand."

When Tom forgot to take along the required photo when applying for a visa at the Japanese Embassy in San Francisco, he borrowed one of Tim's. And at the Association of Tennis Professionals (ATP) awards dinner, Tom introduced Tim, voted "newcomer of the year" by his colleagues, as "undoubtedly one of the ugliest guys on the tour."

"Brian Gottfried still can't tell Tim and Tom apart, and he confuses me with Julie, too," said Rosemary. "When he sees any of us, he just says, 'Hi, Tim-Tom-Rose-Julie.'"

In addition to being fun, both Gulliksons are improving players. The Wisconsin legislature recently cited them as the best tennis players in the state's history, and a high school class in Milwaukee wrote to say it was keeping a Gullikson scrapbook.

Tom's clippings show that he has climbed from No. 113 to 72 in the ATP computer rankings during the last year. Tim's rise has been more dramatic, from 115 to 22. He won three Colgate Grand Prix tournaments on grass last year at Newport, R.I., Taipei, and Adelaide, and shared another title (the final was rained out) at Nottingham, England.

Tim gives much of the credit for his improvement to Jungle, 42, a lieutenant colonel in the U.S. Air Force stationed in Las Vegas. They met when both were teaching pros in Dayton in 1974.

"He had played at Tulane and was the best player in town," Tim remembers. "I started to hit with him and he said he thought I had a lot of potential that hadn't been tested. He was the one who suggested I try the tour.

"He's an inspirational guy who's helped me in a lot of ways besides the mechanics of the game and strategy. He convinced me to look at my first year on the Grand Prix circuit as a time of paying my dues. He kept telling me, 'Tim, if it was easy, everybody would be at the top. You've got to hang in there and learn your lessons.'"

Tom has helped also.

"I beat Roscoe Tanner here in the Washington Star tournament in 1976, the best win of my first Grand Prix season, and then I lost in the first round of the next nine tournaments," Tim says. "I had no confidence, was playing horribly, and got really depressed.On the Asian circuit, Tom really got on me.

"He told me I had to work harder, I had to do this and that. He got me fired up. I think we have an advantage sometimes, because we always try to watch each other's matches and discuss them afterwards."