TORONTO—Edward Norton tries to keep a balance between the worlds of art and activism. Films like Stone, he says, are what keep him interested in acting.

In an interview just before the film’s world premiere at the 2010 Toronto International Film Festival, the newly appointed United Nations goodwill ambassador for biodiversity explained: “Sometimes I do feel some of the larger issues of the world are of such intensity that I kind of feel more engaged by those kind of things. They feel more direct; they feel more urgent. And when that sort of coalesces in my head along with my contempt for what passes for contemporary pop culture, I really start to go off of it. But then I do find my enthusiasm for making films and doing plays and things like that renewed, because I’ll run into a film that reminds me again what I think at its best this stuff can do in terms of having a real cathartic effect on people. It can illuminate things they’re feeling but not putting a name to and get people to look a little more seriously at whatever is dysfunctional or fucked up or needing consideration.”

Norton has a reputation as an actor who likes to have a hand in the scripts, and when he took on Stone (which opens Friday, October 22), he wasn’t sure the role of an arsonist desperate for parole was really there yet. “The character in the script felt pretty vaguely sketched to me.” But because this was his second time teaming with director John Curran—they’d previously made The Painted Veil—Norton was confident things would work out. “I trust John so much; he’s such a serious thinker and filmmaker.” Norton was also excited by the themes Curran wanted to explore. “The idea [is] of a study about authenticity and spiritual authenticity and what happens when someone seems stable but their life is actually inauthentic and goes off the rails, and someone who seems unstable but finds authentic spiritual feeling in their life, settles.”

Norton’s convict Stone is the character who settles. Or at least appears to settle.

Robert De Niro plays a parole officer convinced that Stone is scamming him, and Milla Jovovich plays Stone’s wife, a woman willing to do anything to convince De Niro to find her husband fit to rejoin society.

“John felt those themes related to America and American life and people using structures of marriage and church to define who they are without necessarily having authentic feeling within those structures. So that was enough for me. He said to me, he was really blunt, ”˜I don’t know who Stone is, really, so I kind of need you to invent him”¦All I care about is that this is a guy that when we meet him, he seems like the most unlikely candidate for a spiritual transformation ever.’ ”