"Robert Kennedy and His Times" brings together the work of two different men in love with the same subject.

First there's Arthur M. Schlesinger, Jr., on whose biography the three- night, seven-hour CBS miniseries is based.

And there's Brad Davis, who stars as Kennedy. He undertook a two-week crash course on the life and times of Kennedy and admits that by the time the cameras rolled he was in love with the character he plays. The series, starting tonight at 8, is a friendly affair. Viewers looking for Kennedy family dirt needn't bother looking under this rug.

"I was amazed that I would be overwhelmed by his heart, courage his vulnerability and his shyness," said Davis. "The odds against him seemed to propel him rather than hamper him . . . I was constantly touched with learning about the man's life.

"When someone's been dead for 16 years -- it's hard enough to understand people you know. You never really get to know historical figures. You have to decide what you believe about them" and play them that way.

What Davis believes about Kennedy is that he started out as a shy, awkward youngster with something to prove. "He set a path to prove he was as much his father's son as his two older brothers, to prove he was tough," said Davis. "He was constantly doing things beyond his capability. He was saying, 'I'm a man.'

"There's a lot of the boy in me that's propelled me to become what I am, so I identify with that. I was touched by his childhood and his love for his father and his wanting to make him proud."

In addition to studying the Schlesinger biography, Dvis sought out a variety of people who knew Kennedy, ranging from some who'd said hello at cocktail parties to others who worked closely with him.

"It appeared they were talking about different people," said Davis. "He was obviously a very complex man. How he appeared depended on how you knew him. That's what I liked about the Schlesinger book. There are accounts from people who thought he was anything but touching. Schlesinger touched on -- to use an acting term -- his motivation. Kennedy could be cutting, cold, rude." Schlesinger, added Davis, did not attempt to defend such things. "He looked to find out why he acted the way he did . . . I'm talking about my character -- the Bobby Kennedy I played," said Davis. "I'm not a historian. My job is to interpret."

Davis has been doing a good, if limited, job of interpreting for some time. He first gained wide attention as a young American drug-smuggler who does very hard time in a Turkish slammer in "Midnight Express." Most recently he played Sonny Butt, the bully-policeman in "Chiefs," the most intense character in the miniseries, and there were roles in "Roots" and another miniseries, "A Rumor of War." Add three plays since 1981 and you've got pretty much the entire Davis r,esum,e.

"I do things I really want to do," he said. "I've been pretty picky, I suppose. I like a challenge. That's the only way I grow as a person. A challenge and a love -- having some kind of passion for the character. A love that's not logical . . . I didn't love Sonny Butts, but I wanted to play him. The writer wrote him beautifully -- brilliantly. He wrote a perfect version of an alcoholic and a battered child and a child of an alcoholic . . . Butts was an example of something we're just now becoming aware of. You help people like Butts if you can, and if you can't, after a point, you take them off the street."

In "Kennedy," Davis is surrounded by a highly attractive cast that includes Jack Warden and Beatrice Straight as Joseph and Rose Kennedy, Ned Beatty as J. Edgar Hoover, Veronica Cartwright as Ethel Kennedy, Cliff DeYoung as John F. Kennedy, G. D. Spradlin as Lyndon B. Johnson, and George Grizzard as John Seigenthaler, a Kennedy aide who now edits the editorial page at USA Today.

The series is directed by Marvin Chomsky ("Roots," "Holocaust"), who acknowledged that he made no effort to get all the Boston accents down perfectly, but who did give Davis a partial hairpiece to enhance his resemblance to Kennedy. The series was produced by Bob Christiansen and Rick Rosenberg ("The Autobiography of Miss Jane Pittman," "Queen of the Stardust Ballroom") who, in discussing this, the umpteenth Kennedy TV production, say they think Bobby is the most interesting fellow in the family.

They start his story in 1946, with Robert, age 21, campaigning to get brother John elected to Congress and meeting 18-year-old Ethel. RFK's public life unfolds: His work for Sen. Joseph R. McCarthy of Wisconsin; his relentess legal pursuit of Teamster president James R. Hoffa; his tenure as John's attorney general, sweating out the Cuban missile crisis and the desegregation of the South; his tense relations with Hoover and Johnson; his own political ascent as New York senator and presidential candidate, and his evolution as a figure of hope to political have-nots. The story ends with his assassination in Los Angeles.

While Davis found things in common with Kennedy the boy, there are obvious differences between him and Kennedy the man. "I'm not politically minded," said Davis. "Never have been." His early years were focused on show business. Born in Tallahassee, the son of a dentist, he found Florida pleasant enough but burned to get away. As early as age 5 he was begging his parents to take him to Hollywood. While he waited to make his escape, he surrounded himself with animals -- dogs, cats, squirrels, raccoons, a monkey. He also had a horse and for a time was torn between wanting to act or to become an Olympic equestrian. An uncle, a college voice teacher, got Davis a part in a community theater production of "Streets of New York." That was that. He had to act. After graduation he served an apprenticeship at a summer stock theater in Orlando. Then came Atlanta. Then New York and a role in "The Zoo Story." He was off and running in a career that included daytime TV drama ("How to Survive a Marriage"). In 1976 he married Susan Blaustein and they have a daughter who'll be 2 in April. They also have two dogs and three cats.

The Kennedy role brought Davis a degree of political awareness he says he never had before. When the Kennedys were making their presence felt on the political stage, Davis was looking the other way. "I wasn't into politics then, or pot or school activities. I had two friends. I was simply going to grow up and be an actor," said Davis, now in his mid-30s. "But in retrospect, I felt glad that JFK was my president.

"Robert and John Kennedy and Martin Luther King were products of the '60s and didn't create the era. Robert was the last of them. He seemed to exude, to hold the hope of what that decade was all about. The '60s was a volcano erupting and when everything came down, we felt it would come down in place. We haven't seen any men like these since the '60s. After they were shot, the status quo fell back into place . . . Inspiration lost, and the system won."