NEW YORK -- Move on. Keep changing.

That's what Clint Eastwood sees as the keys to his longevity and success.

Even in the gym "you got to keep ahead of the game," the lanky, 73-year-old filmmaker says, drinking tea in a Warner Bros. screening room. "The cruelty of nature is you have to work out harder when you get older. ... It should be the other way around: Work out hard when you're a kid -- you should be able to coast when you get older. But unfortunately you have to do more to stay in the same position."

In a half-century of filmmaking, he's hardly stayed in the same position.

Asked to explain his enduring career, Eastwood initially gropes for an answer, chalking it all up to luck, before finally settling on a rambling response:

"Probably, knowing when to move on, from doing the Italian Westerns, knowing when to move on, come back home and do some other things, some detective stories, knowing when to move on from those, doing other films, even small films that might not have been as commercial like 'Honky Tonk Man' or 'White Hunter, Black Heart,'" he said in an interview with The Associated Press. "Branching out, and continuing to expand all the time. If you just do the same thing, eventually it just comes to an end. That's why I branched out into directing.

"So instead of them moving on from me, I just moved on from them."

Now Eastwood has moved on to direct a compelling film of emotional claustrophobia, searing pain and misguided vengeance, "Mystic River."

A stellar cast -- topped by Sean Penn, Tim Robbins and Kevin Bacon -- delivers uniformly strong performances in a story about three childhood buddies, one who suffers sexual abuse and another whose 19-year-old daughter is murdered. The bonds and boundaries of their blue-collar Boston neighborhood create a convergence between the two crimes that leads to a Shakespearean tragedy. Laura Linney even delivers a Lady Macbeth-like soliloquy.

Much has been made of Eastwood's evolution from iconic action hero to revered auteur. But there are still those who think he has to live down his early, violent movies.

Richard Pena, chairman of the New York Film Festival's selection committee, can understand how some people find it hard to take seriously the man who starred in shoot-'em-up cowboy flicks, shoot-'em-up detective pics and alongside an orangutan in "Every Which Way But Loose."

Still, Pena points to "Bird," "White Hunter, Black Heart," "Unforgiven" -- which won the 1992 best picture Academy Award and best director for Eastwood -- and now "Mystic River" as evidence of an accomplished, artful filmmaker. (Eastwood's latest opened the festival last week.)

Would look silly in serape

Eastwood says that he's made no conscious effort to retool his persona.

"I'm not that smart, to tell you the truth. I just do projects by what I like and what I feel," he said. "I guess my instincts were in the right place, because I've constantly just expanded and done other types of things over the years. ... I guess I'd look pretty silly right now on the plains of Spain with a serape on."

Eastwood, of course, is alluding to his breakout film roles in the Sergio Leone spaghetti Westerns, which were made in Spain.

During a summer break from playing Rowdy Yates on the CBS series "Rawhide" (1959-66), Eastwood headed to Europe to star in "A Fistful of Dollars" in 1964. It was such a success, two more quickly followed: "For A Few Dollars More" and "The Good, The Bad and The Ugly."

Then he became a gunslinger of a different sort in "Dirty Harry."

But the same year that Dirty Harry first appeared -- 1971 -- Eastwood directed his first feature, "Play Misty for Me," a career path that would eventually bring him to his current status as a senior statesmen of serious cinema.

Eastwood remembers 33 years ago asking the head of Universal to direct: "The guy says, 'Well, that's fine but we want you to do it for nothing. We'll give you a percentage if the film makes a few dollars.' And I said, 'That's fine."'

He likes to think "Play Misty for Me" still holds up and has directed 23 features since then, although only four ("Mystic River," "Bird," "Breezy" and "Midnight in the Garden of Good and Evil") without him in front of the camera.

In all of them, Eastwood hopes filmgoers can't tell he's directing.

He acknowledges he doesn't have a trademark directorial style. Rather, he says, it's dictated by "what the picture demands." He wants his direction to be a seamless complement to the story.

His directing technique is unique, however, says Oscar-winning actress Marcia Gay Harden, who plays Robbins' frightened, disloyal wife in "Mystic River" and co-starred with Eastwood in "Space Cowboys," which he also directed. He's low-key and doesn't yell "Action!" and "Cut!"

To keep actors at ease, "I usually just say, 'OK, go.' And 'Stop,"' Eastwood says.

Yelling "Action!" might cause too much adrenaline to flow for a particular scene. The technique goes back to "Rawhide," when the director would scream "Action!" and the horses would get spooked. So he suggested to the director, "What don't you just say, 'Come ahead."'

The horse whisperer of directors hopes he's made a film for grown-ups with "Mystic River." If anyone's looking for "The Matrix Reloaded," they're going to be disappointed.

"I like to think that adults, a lot of thinking adults, want to go out to a movie that makes them think a little bit and gives them something to participate in mentally rather than sit back and be barraged by people sliding back and forth on wires," says Eastwood, who also wrote the movie's music.

He has no immediate plans for his next film, intending to bask in the joys of cozy family life.

Before the interview, his wife of seven years, former California local news anchorwoman Dina Ruiz, kissed him before taking a walk to kill time until his appearance on "Charlie Rose."

"Is that cool with you? Did you need me at the hotel?" she asks.

"No -- I mean, I always need you, darling," he says, then offers the joking aside: "Am I saying the right thing?"

On her way out the door, she kids: "I won't spend too much!"

"It's great. It's terrific," Eastwood later says about his current personal life. "Because when my first children were born, I had the brass ring and I was running with it. I took a lot of jobs.

"I love those kids and we get along (now). But in hindsight I would have loved to have spent more time with them. But it was my chance to make a few dollars and be able to provide well for the family."

(Eastwood has seven children altogether: 6-year-old Morgan from his current marriage; 10-year-old Francesca from his relationship with Frances Fisher; two from his first marriage, including actress Alison, 31; and three children from two other women.)

Now with a 10-year-old and a 6-year-old, he says, "My career can go into second position, to them. I'm going to make sure they have the best I've got to offer."

Meantime, he's not thinking about retirement.

"But I'm just going to take more time in between and do only projects I'm really convinced I want to do," he said. "No working for the sake of working."