Matt Dillon is pondering the implications of his latest – and arguably most controversial – film in his four decades on screen. He's the lead in Lars von Trier's latest provocation, The House That Jack Built. Played by Dillon, Jack is a serial killer with a long history in murder and maiming. When the film premiered in Cannes earlier this year, some of the more graphic and disturbing moments caused walk-outs. 'I understand why people are upset,' he says, 'I get it. I'm upset! I almost didn't do it because I was afraid I wouldn't be able to handle it.'

From Gus Van Sant's Drugstore Cowboy to Paul Haggis' race drama Crash, which won Dillon an Oscar nomination, the 54 year-old has never been afraid of challenging projects. But this taboo-busting tale took some steel from the actor, who almost quit in the run-up to the shoot because of one scene that 'troubled' him, as Jack carves up his own girlfriend (played by Riley Keogh) in a particularly shocking manner. 'In the end, I did it, because of Lars,' says Dillon. 'He takes on very dangerous topics and he does them with certain flair and turns [them] into art in a way.'

The same could be said for Jack, who arranges his corpses tableaux-like, the ultimate presentation of his life's work. Sick and twisted? Yes. But compared to mainstream action movies with high body counts? 'The violence is not gratuitous. It's graphic and he [von Trier] wants you to be horrified,' says Dillon. 'If you're upset, I think he wants you to be upset in those moments.' It's all about freedom of expression, he continues: the director has the right to show you, just as you have the right to turn away or walk out. 'But it's not real, it's art.'

The New York-born Dillon has always made a beeline for artists; he worked with Francis Coppola on 1983's Rumble Fish and The Outsiders back when he was starting out. But I wonder how he's enjoyed such career longevity in such an unforgiving industry? 'I just never gave up doing what I do. I very much believe in myself. Maybe more than other people do sometimes. That happens. I try to learn as I go. I've been trying to learn all the time.' So what did he learn on The House That Jack Built? 'I learned on this not to be a perfectionist. Let's allow ourselves to fail. So we can do something even greater.'

The House That Jack Built is in cinemas from Fri 14 Dec.