"I always felt a pervasive sadness," Brad Pitt tells me. "I'm not sure I earned it, because it was always there. It existed in the place where I grew up--in my family, in people who have true sweetness and true goodness. Maybe it's a congenital sadness that everyone has to some degree."

Brad Pitt, 43, one of the world's most recognized stars, says his life and beliefs are informed by this sense of existential sadness. It is what drives him as a man and an actor. It is also what makes him want to fix the world.

"Maybe an offshoot of it is the discomfort I feel when other people are unhappy and wanting," he suggests. "When I see someone without basic health and education, without a supportive family, I feel a connection. That's what moves me the most. I could be him, if I'd been born on some other dot on the map."

Brad Pitt and I recently spent some time together in Toronto. What is most impressive about him is not his good looks and movie-star glamour, things he has in spades. Rather, it is his openness and empathy with people who are hurt. There is much of the generous, unspoiled American boy in his character, a kind of innocence. He truly believes he can help mend broken lives and change the world. And that, he says, makes everything else he does meaningful.

"Whoever said all men are born equal never left his own backyard," Pitt asserts. "I see people everywhere without opportunity. I want to help level the playing field."

Pitt grew up in Springfield, Mo., the oldest of three children in a conservative, Southern Baptist family. His mother was a school counselor; his father ran a trucking company.

"My dad made sure our needs were met," he says. "I had a very loving family." When he speaks of his childhood, his voice softens with the accent of his youth.

"I always had a lot of questions about the world, even in kindergarten. A big question to me was fairness. If I'd grown up in some other religion, would I get the same shot at Heaven as a Christian has? My mom would come into my room and talk to me. I was very fortunate to have that dialogue with her, but in high school I started to realize that I felt differently from others."

Brad went to Springfield's Kickapoo High, excelling at school debates and sports. As he got older, his religious doubts increased.

"I had crises of faith," he says. "I thought you had to experience things if you want to know right from wrong. I'd go to Christian revivals and be moved by the Holy Spirit, and I'd go to rock concerts and feel the same fervor. Then I'd be told, 'That's the Devil's music! Don't partake in that!' I wanted to experience things religion said not to experience."

By the time he entered college, Pitt had scuttled his fundamentalist beliefs. "When I got untethered from the comfort of religion, it wasn't a loss of faith for me, it was a discovery of self," he says. "I had faith that I'm capable enough to handle any situation. There's peace in understanding that I have only one life, here and now, and I'm responsible."

Pitt's causes range from rebuilding New Orleans to AIDS care in Africa. Last year, among the millions of dollars he and his companion of two years, Angelina Jolie, donated to charity, $1 million was given to Doctors Without Borders, another million to Global Action for Children.

"It's not just altruism," he insists. "It's not a payback. Philanthropy is good for us. It's in our own best interest. It's personally rewarding when you see lives change because of an action you take that, though simple for you, means so much to others. You sleep peacefully at night."

I ask if his charitable work is the result of hisrelationship with Miss Jolie.

"That's idiotic!" he replies. "I do it because I'm a member of the human race. In Africa you see people on the street dying from AIDS, children left without parents. We're all cells of one body, with the same emotions and desires for our families--for a little dignity and a chance for a better life. Let's focus on that! I believe in the founding principles of America. I want to fight for that. I know most Americans feel the same way."

I suggest that he run for political office.

"Oh, my God!" Pitt says in surprise. "I never thought about it. I have no desire at this point. Maybe I serve better by not going through that door." He laughs. "George should do it!" he says, offering up pal Clooney. "He'd be quite good. I think Ben Affleck should run."

Brad Pitt was in Toronto for the film festival's screening of his new movie, The Assassination of Jesse James by the Coward Robert Ford. He stars as the outlaw James, one of America's first murdered celebrities. It is a magnificent performance that's likely to win him an Oscar nomination.

Pitt's journey to stardom began in 1986, two weeks before graduation from the University of Missouri, when he suddenly dropped out and headed to Los Angeles.

"I had this sinking feeling as graduation approached," he says. "I saw my friends getting jobs. I wasn't ready to settle down. I loved films. They were a portal into different worlds for me, and Missouri wasn't where movies were made. Then it hit me: If they didn't come to me, I'd go to them."

In L.A., he took acting classes and worked at odd jobs. Within nine months, he began to land small parts on TV and in teen flicks. In 1991 he had a small role as Geena Davis' boy-toy pickup in Thelma & Louise. It made him famous. Everything followed from there.

"When fame really hit me was when Legends of the Fall was released three years later," he says. "You get no warning about what celebrity is or how to deal with it. It's sort of multitiered. The initial stage is feeling discombobulated and not up to the task. I didn't understand the incessant attention when I went outside, the way people completely focused on me. It made me very uncomfortable.

"Then you start to see the fickleness of celebrity," he continues, "that it isn't rooted in something of real value. There is this strange wanting by people to get next to you. It has nothing to do with you but with something they feel they are missing in themselves."

Brad Pitt's fame increased exponentially after Interview With the Vampire, Troy and the three Ocean's caper films. His outsized celebrity also was powered by his romances with actresses Juliette Lewis and Gwy- neth Paltrow, his very public marriage to and divorce from Jennifer Aniston, and his current relationship with Jolie, 32.

"I understand the tabloid machine," he says. "There's money to be made off of Angie and me, but it has gotten so out-of-hand. There's no decency, even when it comes to our kids."

Jolie and Pitt have three adopted children--Zahara, 2, Pax, 3, and Maddox, 6--and a birth daughter, Shiloh, 16 months.

"I mean, yesterday Angie was taking Maddie off to school," he continues angrily. "There were 30 paparazzi outside. One guy sticks a video camera in Mad's face, yelling, 'Maddox! Maddox!' He doesn't get a response. He doesn't know my boy. Mad is already savvy to this, unfortunately. But my 2-year-old dreads being anyplace there are cameras. It scares her. They're all in her face. My kids are faced with this every day! It's disgusting. So we've been run out of L.A., all the major cities. We just can't live there. You don't understand--this is the hunt, the hunt, the hunt! I thought it might be over a year ago. It's gotten worse."

He pauses, shaking his head. For a moment, I glimpse world-weariness in his blue eyes, affecting and sad.

"What's important to me is that I've defined my beliefs and lived according to them and not betrayed them," he says. "One of those is my belief in family. I still have faith in that."