The whole truth, nothing but the truth, so help him?

That's the oath sworn by Bernard McCullough - the bug-eyed giant you know as Bernie Mac.

The clown with the frown greets you in wincing pain, a bad case of the piles, he says. Proffer tea and sympathy and Mac erupts with volcanic laughter. Just kidding. He's perfectly OK.

"People don't give comedians credit for being great actors, but we're the best," he says. If he sounds immodest, check out his turn as Elston, Philadelphia Department of Recreation maintenance man, in Pride.

In the true-life inspirational about local hero Jim Ellis and his creation of an inner-city swim team in Nicetown, Mac delivers a characterization as vital to the film as Terrence Howard's lead. Where the comedian's stage act is in-your-face, his film work is more subdued, more in-your-heart.

"Comedians are great actors," he contends, "because of their imaginations. They know how to go into character and hold the audience's attention," he says, punctuating his words with those eyes that have never conceded a stare fight.

Dapper in denim - call it a millennium version of a leisure suit - and custom-made alligator boots, Mac is considerably slimmer than he looked on his eponymous Fox sitcom. Truth be told, the guy famous for playing the grumpus with the moral compass in hit movies like Guess Who and Mr. 3000 looks considerably happier, too.

If the entertainer, who is 49, is swelling with Pride, it's because he knows firsthand how a community center can make a difference. Mac is a veteran of Chicago's South Central Community Center.

"I was in charge of athletic programs and, like Jim Ellis, worked to get funds for kids who were single-parented." He knows the experience of "planting the seeds of hope, of giving them sun."

Mac is the product of a single parent, Mary, who died of cancer when he was 16. Like pearls in his vest pocket, he carries Mary's maxims close to his heart. He calls them "Mac-isms," and flashes a few to give a sense of what got him through the tough times, the lean years of driving UPS trucks and delivering bread:

How you start is how you finish.

Believe in something or believe in nothing at all.

Sometimes when you win, you lose; sometimes when you lose, you win.

To keep from crying, Mac made people laugh.

He was 19 when he started out in Chicago's comedy clubs, so broke that he had to borrow a suit from his brother. He was also expecting a baby with his girlfriend, Rhonda. (They married. Their daughter, Je'Niece, now 29, has her master's in mental health.)

Mac was 32 when his stinging social commentary won the Miller Lite Comedy Challenge. He began earning gigs warming crowds for singers such as Natalie Cole. Then came regular appearances on HBO's Def Comedy Jam, his own cable variety show, Midnight Mac, and the phenomenal "Original Kings of Comedy" tour, memorialized by Spike Lee in the hit 2000 documentary. In less than a decade the gadfly became an institution.

Small roles in small movies like The Players Club led Mac to big roles in big movies like Charlie's Angels and Guess Who. He spun quips into the memoirs I Ain't Scared of You and Maybe You Never Cry Again. His grouchy and hilarious sitcom - W.C. Fields meets Father Knows Best - drew from his own fatherhood struggles, which bore little resemblance to The Cosby Show.

The "Original Kings of Comedy" raised Mac's profile. But he's resisted recent pressure to join a "Kings" reunion tour. "I want to do comedy for me," he says. And by this he doesn't mean his return as one in the crime crew of Ocean's 13.

His next comedy gig will be his last, threatens the entertainer, who contemplates more dramatic roles like Pride.

Mac says he's hanging up his mike after he does his final stand-up show this year, "The Whole Truth, Nothing But the Truth, So Help Me, Mac."

"I've spent 30 years in standup, time to retire." Retire from the career that made him a star?

"I'm not a star," he says with a shrug. "Stars fall."

But Mac always rises.