Dafoe admires Lars, but "his impulses are often perverse."

Has there been a more harrowing and courageous performance this year? Willem Dafoe plays a wholly evil man occupying a wholly evil world in Lars Von Trier's "Antichrist," a new film that challenges its viewers so boldly that some have fled from the theater. Von Trier's films often stir up heated discussion, but never has he made a film quite this formidable.

Dafoe, known for his risk-taking, plays the Man opposite Charlotte Gainsbourg as the Woman, in a film without other characters except for their baby, who dies in the opening sequence. Although the film never says so, their relationship is founded on the reality of a universe without goodness. It seems to me this is necessary if you introduce an Antichrist figure, just as matter is impossible in an Antimatter universe.

Whatever the interpretation, there's questioning the extremes von Trier demands from his actors. Dafoe has repeatedly played difficult characters for great but demanding directors. Indulge me in making a list: Paul Schrader, Werner Herzog, Abel Ferrara, Theodoros Angelopoulos, Oliver Stone, Spike Lee, Martin Scorsese, Sam Raimi, Wes Anderson.

Even in this company, von Trier has a reputation of being the most difficult; after "Dogville," Nicole Kidman was quoted as saying she not only didn't want to act for him again, but to ever speak with him again. Yet "Antichrist," which opens Oct.23, is Dafoe's second film with von Trier, after "Manderlay."

It's not a love affair. "His impulses are often perverse," he informed me, adding the mixed compliment: "He's one of the most bitterly funny people I know." We shared an exchange via e-mail:

Q. What did von Trier say was the meaning of the story?

A. Lars spoke nothing of the meaning of the story. He did share the origins of the screenplay, which grew out of a collection of personal images, dreams and anxieties that haunted him in his depression, that were organized around the idea of these two people confronting a Nature created by Satan, not God.

Q Did you agree, or did you use your own inner interpretation?

A. I didn't feel the need to interpret the story. In a film where there are basically only two actors, you become the story. I felt like I could best serve the film by looking no further than each scene and having no particular design outside the character's objective in each scene. I had no real interest to craft an arc of a performance. If you have an interpretation of the story, as an actor, it makes you more self-conscious and you measure your impulses. In this case I felt it would inhibit me.

Q. What sorts of discussions did you have with Charlotte Gainsbourg about the nature of your performances?

A. Our communication was an unspoken trust in each other which was formed by mutual fear, confusion, respect, and a desire to give Lars what he needed. We discussed very little.

Q. In your experience, how do actors feel about performance intimacy that violates their personal space?

A. Many actors have a not-so-secret desire to expose themselves emotionally -- and in some cases, literally! If you really are committed to playing, to becoming, a character, you don't really have personal space. Vulnerability becomes strength. Some people feel stronger with their clothes off, or doing private things publicly.

I think sometimes people want to "play house" when they have intimate scenes in order to assure they become practiced at intimacy or to encourage chemistry for the camera. With Charlotte and I, we had great intimacy on the set but the truth is we barely knew each other. We kissed in front of the camera the first time, we got naked for the first time with the camera rolling. This is pure pretending. Since our intimacy only exists before the camera it makes it more potent for us.

Q. You've been fearless in your choice of roles. Yet from all I know and have observed, you're far from a wild man -- instead, a thoughtful, kind, private person. What resources do you summon to take on such challenges?

A. I suppose I am a fearful, average man in life and cling to social conventions like most people so as not to be vulnerable. Grace, manners and form in behavior is very important to me. My upbringing has instilled in me the importance of self-reliance and "don't burden anybody" -- for better and for worse. In film, in telling stories, in inhabiting characters, I have an opportunity to play out fantasies, test limits, empathize with people unlike me, think the unthinkable in an environment, a form.

I feel free to play with my darker nature and test it in a constructive way. Challenges that engage you in a full way become so seductive and consuming that you don't think about consequence or failure you only think about the quality of being there -- which can become totally intoxicating and transforming.

Q. The Antichrist of course represents in Christian terms the antithesis of all that is right and good. My theory is that the film suggests a world lacking all joy and virtue. Your character is not evil by choice but is acting out his nature. What's your theory, from this sort of theological POV?

A. I don't know about the theological…my character's well meaning, but arrogant. But he comes to accept a kind of darkness, an utter futility. Admitting helplessness, acknowledging unpleasant truth. Far more than we could possibly imagine. We cannot save ourselves. Imagined knowledge blinds us. This kind of journey puts us me touch with our humanness and awakens compassion for ourselves and others.

Q. You've worked with an astonishing variety of great directors, including von Trier before. What distinguishes von Trier?

A. Lars' impulses are often perverse. He has an incredible knack for considering the tabu, the unthinkable, the suppressed thoughts and actions that reside inside of us. He has incredible technical facility as a filmmaker but he subverts it -- almost as his duty as an artist. He is also one of the most bitterly funny people I know.

Q. I have a film festival that honors overlooked films that deserve more attention. I've long felt "Shadow Of The Vampire" falls in that category. Agree? Other films you wish more people had seen?