Peter Fonda is, as ever, tall, lean, tan and contentious. He wears gold beads around his neck, and three stars tattooed on his forearm. His face bears the rewards of age and sun. He's 45 now, as restless and rebellious as a youth. He still rides a motorcycle.

At his age, his father Henry Fonda had just finished the stage version of "Mister Roberts" that helped identify him as an all-American hero. Peter Fonda made his "Easy Rider" when he was 29, playing not a Navy lieutenant but a biker with an American flag on his helmet, blasting across the countryside toward a rendezvous with the end of a shotgun.

Since then there have been more than 20 movies, some good and some not, none as much a part of its time as "Easy Rider." In his life he has coped with three suicides, divorce, a famous but uncommunicative father, boarding schools, a phenomenally successful big sister, unemployment and rejection, and he is not an easy man.

Even lying back in a chair, swigging a beer and exuding -- for a moment -- a certain mellowness, he's still a coiled steel spring. He talks in long sentences larded with profanities, in paragraphs, chapters, sometimes getting lost in subsidiary anecdotes. Emotions come bubbling to the surface like hot lava, smoking with tension. He still rides with family demons, leaving them behind in the dust only to see them turn up like ghostly hitchhikers around the next bend.

"I'm a short-fuse concussion grenade," he says sadly, almost mumbling to himself near the end of a two-hour interview. "Somebody pulled the pin when I was 10 and the spoon dropped and I've been going off ever since. It's no fun for me."

But: "The family motto is perseverate. Persevere Ye. It is not a suggestion. It is a command. Sometime between when the family was founded and 1985 they knew they'd have me to contend with as one of the last of the Fonda line, so they made it inescapable."

He subscribes to two magazines: "I get my politics from Mad and my information from Scientific American," he says. "With that and 12 years of Latin, I can take on anybody."

Peter has never been tarred by politics like his sister Jane, whose name still brings curses from some Vietnam veterans. He opposed the war, but voted for Barry Goldwater, thinking Goldwater would end it sooner. His main concern now is what he terms a "cancer of our citizenship that could spell the destruction of our democracy," which he explains this way:

"We used to be a nation of people who could fix things for themselves . . . Fix the tractor, the table, grow your food, have the baby in the barn. Now we want someone else to fix it for us . . . We want the government to take care of us. Who's going to run the government, a bunch of goddam nannies? Dutch and Mummy?"

The opinions come pouring out, iconoclastic and irreverent. Owning property is nonsense, having "In God We Trust" on our coins is wrong, "E Pluribus Unum" is what's important, and if we don't understand that "we'll be taken over by fundamentalists."

He's concerned about teen suicide, and talks to teachers and social workers hoping to help them better communicate with teen-agers. That's his cause. "I try to promote perception, rather than intellectualization . . . These are questions without answers. In suicide, for example, it's why? What is the meaning of life? This is a stupid question . . . What's important is what we will do with where we are right here, right now. It can be muddied very quickly with 'Why are we here?' We're here. You don't need to know any other information."

As a child he flirted with death himself, unconsciously. Playing with friends, he shot himself with a rifle, blowing a bullet through his stomach and kidney. He did that a few months after his mother died. He did not know until years later that she had killed herself, and that knowledge -- that lack of knowledge -- still festers.

"There was a tremendous conspiracy in my family life," he said. "I was left out. I was not left out because I was someplace else. No one told me. I can't begin to describe to you what that deceit means to me . . . My mother was just a small part of the bugaboo. When you ask questions to people who do not answer, or who have no words . . .

"As far as I can tell, I was consciously kept in the dark. I haven't the foggiest idea why. I used to think about reasons in order to work it out within my own mind. My major in college was not drama; it was child psychology. I wanted to figure out myself, who I am. I was Henry Fonda's son, but that's not who I am. You know what? I am the smartest member of the family, so maybe they figured if they told me I'd go berserk and kill them . . ."

As he talks his voice gets low, thick and heavy. The wounds, while not fresh, have still not healed, like scars torn open repeatedly just as the skin starts to mend.

His current project is a long-awaited film with his sister, based on Lacey Fosburgh's 1983 novel "Old Money." Fonda is producing and working on the screenplay as well as acting.

"We've been through two scripts so far that have been total bombs," he says. "We want to bring to the screen old money and the way it carries on. And brothers and sisters are that relationship which is so traumatic and dramatic. It will be motivated by mystery. It's not a Eugene O'Neill thing where we're going to sit around a table and yell at each other . . . Although everybody will come and see whatever Jane and Peter are going to do together because they want to see that, but we're not going to just sit down and yakety-yak."

It's not hard to see why the Fondas might be attracted to "Old Money," which is about a socially prominent family not unlike their mother's. The story traces a young woman's struggle to find out why her seemingly unimpeachable father disinherited her. It is also not hard to see why writing the screenplay might present some problems. One is that the central character does not have a brother.

Such a project has been talked about for several years, and represents a considerable mellowing of a relationship that is not always easy. In many ways he will always be Little Brother.

She got good grades, was pretty (after shedding her adolescent plumpness), and along with her high-profile social conscience, has been enormously successful financially and artistically. Little Brother was sickly and skinny, always in trouble, and never repeated the commercial success of "Easy Rider," even though his films have been varied and unusual.

So how is it working on a screenplay together?

"We don't have fights . . . For a while she was pulling the Big Sister routine, but I said, hey, shine that one, Jane . . . Like she said to me -- with the best of intentions, I mean I love her, I love all my sisters, I'd kill for them -- nevertheless, she said, 'I think you're a good actor, but you haven't had the chance to work with some of the great directors like I have.' And I said, 'What do you mean? I've worked with Robert Rossen and he wasn't too shabby. Dennis Hopper directed "Easy Rider" and he's a very talented person. And I've worked for myself three times. What great directors haven't I had a chance to work for?'

"Once she called me and said, 'Hey, I've done this interview and I don't want you to take it wrong, 'cause it sounds like I'm the big sister saying my little brother is helpless.' And in the back of my mind I'm saying why didn't she call me before the Cosmopolitan article in 1962 where I found out what happened to Mom? That's the one when she should have said, 'Hey, Peter, you better come over here, I've got something to tell you and it's going to blow your mind.' "

(In "Fonda: My Life," Jane said she told Peter when he was 18 that their mother had slit her throat with a razor. In the same book Fonda said he had no memory of that conversation.)

"There was no cause for me picking up Cosmopolitan and reading about it . . . And even after that revelation, no further words, nothing. They're all dying real quick, too, the elders of the Fonda family. Now I am the Fonda family, me and my sister Jane."

As he talks, the late afternoon sun beams a spotlight on his face. You begin to think maybe Eugene O'Neill might be the right author for the Fonda family after all.

"You know, my stepmother and my sisters are terribly worried that I might write a novel . . . It would just devastate them.

"Of course, it would be a biography. I have the most logical and applicable point of view. It terrifies the remaining living members of my family to know: He does remember."

So why doesn't he write a book? "Nooo, I'm not going to put it in a book! I said to Jane, 'Book? What book? One of the chapters, Jane, will be called "Don't Tell Dad." ' 'No! Oh, Peter!' I said: 'You'll love the chapter, Jane.' "

He mimes turning a page, saying a word for each page: "I-never-told-Dad -- anything . . ."

But hasn't he put it all behind him, made his own life and family, "fixed" it for himself?

"It's all behind me unless someone asks me about it," he says slowly.

It is only later you realize that you never asked.

Fonda was sent to boarding school at 11, a boys school in Southborough, Mass., where, he remembers, he devoted himself primarily to fabricating explosives. A school picture shows a scrawny, worried-looking lad, with a shock of straight, slicked-back hair. He was cast as a girl in the chorus of a school production of "The Pirates of Penzance," and, determined to avoid that ignominy again, wrote his own play, "Stalag 17 1/2," and produced it with some schoolmates.

He went to the University of Nebraska at Omaha, where a school production of "Harvey" brought out his love of performing. Soon he was following his father's and sister's footsteps, acting in "Blood, Sweat and Stanley Poole" in New York in 1961 and winning a Drama Critics Circle award for most promising newcomer.

His first movie was "Tammy and the Doctor" (1963), in which he played Sandra Dee's love interest; in "Lilith" (1964) he played a resident of an asylum who commits suicide when rejected in love. After a series of B movies, some of them cult classics (such as "The Trip" 1966), came "Easy Rider," which he produced, cowrote (with Dennis Hopper and Terry Southern) and starred in. Its message, that nonconformists are persecuted, was lapped up eagerly by the '60s kids who were doing their best to flout every convention, real or imagined.

"That movie is still playing 24 hours a day in Paris," Fonda says, exaggerating a bit (it is not now on exhibit there). "Even as we speak it's being shown at probably 180 to 200 theaters around the world, if not double that amount."

The movie cost $373,000, he says, and has grossed more than $80 million. But a different price was exacted, he says. "The major studio system sees me as a threat, even today." As he sees it, renegade independents making a profitable movie on a low budget are like defense contractors producing a hammer for $7.50 instead of $500; the big boys don't like it.

In the years since, he has directed three respectable but unprofitable movies, "The Hired Hand," "Idaho Transfer" and "Wanda Nevada," which starred Brooke Shields and featured Henry Fonda in a cameo. And there have been parts in things like "Cannonball Run," "Dance of the Dwarfs" and a number he concedes are clinkers -- "I've got three children in school," he says.

When he is not working on a film he is "waiting for the phone to ring" or trying to put projects together. He estimates that most of his work has developed through his own efforts, just as "Easy Rider" happened through his and Hopper's efforts. "Never once in my mind did I think, 'This won't happen.' It was my ability, not my determination, that made it work. It was my desire that made it happen."

He was in Washington to be a celebrity at the Cancer Ball. He was glad to do it, but, he said, "I'd rather be acting. Or directing, producing, hanging a light, running a camera. I love all parts of it. If I had a great voice I'd go out and sing for $20 a night."

Another story:

During the Vietnam war, Fonda told friends that if they opposed the war, they should resist the draft, but not go to Canada or Sweden. "I said, 'Pay the price for your protest. 'Cause your ability to protest is something that is not free. You have to earn it.' "

When his number came up, Fonda went to his draft board for a physical, but refused to undergo the routine Army proctological examination, to put it more politely than he did.

"They sent me to the shrink's room and the shrink said, 'Are you an actor?' and I said yes. And he said, 'Are you acting right now?' . . . And I said, 'Oh, a wise guy.' I had filled out the form. And he said, 'Who told you this stuff?' his medical history . . . and I said, 'My mother.' And he said, 'And did your mother tell you to come down here and tell us this?' And I said, 'No, my mother committed suicide by slitting her throat from ear to ear when I was 10. And you're a psychiatrist? You're lucky you haven't bitten your nose off yet.

"There was a guy behind me -- none of us had any clothes on -- his leg was only as big as my right arm. This man's going to go to war? What are they putting him through this for? I got really pissed at them for that. They were yelling at him -- I said don't take it, you're a civilian. You can yell at them . . .

"I told them I was an expert shot, and I am. I'm a perfect assassin. My only problem is my philosophy that whatever I kill I should eat.

"I said, look: give me a gun and the first person I'll shoot is the first one who says, 'Ah, well, Henry Fonda's son' . . . I'm not going to stand for anybody else using me as a whipping boy. Any authority used for its own sake is something I will go out of my way to point out, crush, destroy, in any way humiliate.

"I said to the shrink, 'It's going to be on your hands, pal. It might be an admiral, it might be a general. It might be anybody who said 'Ah well, you're Henry Fonda's son, huh? Well, you're just a Gobby.' That guy is going to get knifed. I won't put up with it anymore. I don't need to. I'm 23 years old and I'm in charge of my life. You're not."

He marched out of the draft board, he said, and was halfway across the street before he realized he was stark naked.

They classified him 1-Y, a medical deferment. He tore up his draft card and sent it to President Kennedy. "I knew it was a $10,000 fine or 10 years in jail. But I never heard a word."

When Peter Fonda isn't working on a film he lives on a ranch in Montana or on an 82-foot ketch named Tatoosh, which he bought in 1969 with profits from "Easy Rider." He has a master seaman's license and says he has sailed more than 180,000 miles, primarily in the South Pacific (a statistic that other sailors suspect is exaggerated). Before his children entered high school, he lived on the boat.

"Usually I'm sailing because I have to decompress in order to relate to civilians . . . It's like a diver who goes very deep in his dive and has to come up quite specifically . . . I'm not escaping intellectualism, I'm not escaping bad air in Los Angeles. I am decompressing."

He never, he notes, has paid crew, a point of pride for some captains, particularly those known not to be impoverished.

He has been married for 11 years to Becky Crockett McGuane, formerly married to novelist Thomas McGuane, still a neighbor in Livingston. Becky is small, with a perfect, curvaceous figure and curly blond hair. She is bright and friendly. Fonda openly adores her, calling her "sweetheart," telling her she looks great. Fonda refers to Thomas, her son by McGuane, as his own. He refuses to use the word "stepson." His two older children, whose mother is his first wife, Susan Brewer, are in college: Bridget is a junior at New York University and Justin a sophomore at Montana State. Thomas is slated to enter Montana State next year.

"I've raised him since he was 6. I have been his only and visible father, although he knows who his real father is."

Becky likes sailing, he says, although she has a fear of dying in the water. They have not had children together, he says, because "poetically or idiotically, I said, 'Our love is our child. That's the child we have to bring up.' "

"I have a wonderful wife, the best," he says. "I have three beautiful children. I have the privilege of being an actor, a director, a producer, a writer. I am a happy man. Not content -- but contending."

His wife, he adds, "loves artists." It's lucky, he says, leaning back. "Because I'm not easy."