Paul Whitty isn’t a bad guy. He just acts like one. On stage.

In fact, among Charleston’s deep pool of acting talent, Whitty is one of the best bad guys out there.

In Defiance, he played an unctuous military chaplain with a hidden agenda. In Doubt, he was an ambiguously pedophilic priest. In Hogs, he was a slick mayor of a South Carolina town whose political ambitions are so great he sells out his own sister. And in Faith, Hope, and Charity, his badness really came out.

“I played an assortment of crappy people,” Whitty says with a laugh.

Whitty is really very good at being bad. He’s believable. And that credibility is abundantly evident because of his approach.

That is, his characters don’t believe they are bad. They come up with all manner of rationale to convince themselves they are doing good.

“I learned that from a near and dear teacher in college,” Whitty says. “Even someone as evil and warped as Hitler had his own justifications. When I play bad guys, I don’t judge them. Instead, I try to understand how they understand things.”

That’s some serious thinking by an actor who didn’t think he’d play serious roles. His background and training is in comedy. For all the work he’s done in Charleston, only recently has Whitty shown theatergoers his comedic chops.

First, it was Sheep’s Clothing, an original play by PURE Theatre about high school coaches whose way of life is disappearing before their eyes. His character, Luggs, marks the passing of time in his locker room by putting on and taking off his socks.

Now comes Art, about three friends struggling to understand why one of them bought an audaciously expensive piece: a white painting on a white background with fine white stripes.

“I’m a bit relieved to be doing comedy again,” Whitty says of his new role, which is part of Piccolo’s Stelle di Domani series. “It’s nice to play a guy who’s a little more upbeat and likable.”

The premise alone is funny, if you have a taste for the absurd. So is the characterization of French playwright Yasmina Reza.

After Serge (played by Jamie Smithson) buys the all-white painting, his friend Marc (Paul Rolses) is scandalized and sent reeling over this challenge to his aesthetic authority. Meanwhile, Yvan (Whitty) is left to mend the gap that’s widening between all three of them.

“Yvan is a kind of nervous guy,” Whitty says. “He doesn’t like conflict. So it goes back and forth between Serge and Marc. It culminates in a discussion about art, but it’s really about friendship. It asks, ‘Am I who I am because of who I am or because of who you are?’ ”

Hmm. Sounds pretty serious.

But Whitty says there’s lots of laughing in this award-winning play (translated by Christopher Hampton). And a lot of the fun comes from working with his old buddies Smithson and Rolses.

Smithson and Whitty in fact hail from Myrtle Beach, and performed Art a decade ago (Whitty played Marc back then). While they were gearing up for Art, Whitty says, he realized how their friendship had changed over the years, a positive reflection of the negative changes that take place in the play.

It’s an “art-life parallel” that he enjoys. Why?

“Because art has a practical application,” he says. “It’s not just theory. You grow into a part and it becomes you. It’s an important part of creating.”

So do bad guys become you, too? No, Whitty says.

“Playing bad guys is like my therapy,” he says. “That way, it’s not part of my real life.”