Bond, Batman and Titanic can explain the workings of the world, reckons Slavoj Žižek. Danny Leigh joins the superstar philosopher on the set of his latest bizarre voyage into cinema

Slavoj Žižek is in bed. He's wearing cheap pyjamas in a porridgy shade of grey. He looks exactly like the photographs I've seen of him: fag-ash beard, ghostly complexion. I loom over him, and he glowers back. His face is just inches from mine, so close I can feel his breath.

"No, you are wrong!" he hisses. "My dreams were not really mine! That's why I wanted to be reborn!"

None of this is a product of my subconscious. In fact, we're at a studio near Dublin, working on The Pervert's Guide to Ideology, a film in which the Marxist provocateur and bestselling philosopher is starring as himself, albeit in a series of loving re-creations of movie scenes. What's being mocked up now is a key moment from the 1966 classic Seconds, about an unhappy executive who assumes a new identity. Žižek is in the Rock Hudson role. I have been handed a pair of glasses and am appearing as a supporting character. Or rather, the back of my head is.

Žižek scowls at me a second longer, until a woman calls out: "OK, thank you, Slavoj. Let's do it again – but can you two get closer this time?"

The voice belongs to British documentary-maker Sophie Fiennes, who also directed 2005's acclaimed The Pervert's Guide to Cinema, in which Žižek delivers inspired rereadings of classic movies, ultimately suggesting that cinema may in fact be more real than the mundane world outside the darkened theatre. Fiennes hit on the idea of restaging the movies Žižek was discussing and dropping him into them. Now the pair have reunited for a sequel. This time, however, the subject isn't film but ideology itself, something he thinks now goes largely unquestioned.

"We all accept liberal democratic capitalism, even during this current pan-European disaster," Žižek says. "We timidly ask, 'Oh, can we have a few more rights for minorities? A little more healthcare?' But nobody questions the frame. And that is the real triumph of ideology."

Cinema remains the vehicle, though. The last few days have seen reconstructions of Full Metal Jacket, Taxi Driver, Stalinist propaganda piece The Fall of Berlin, cult sci-fi movie They Live – and The Sound of Music, in which the star skewers commodity fetishism while dressed in a cassock. But whatever the costume, whatever the scenario, the constant is Žižek, his analysis and context for all this delivered at a breakneck pace, spilling out in a torrent of lisps, mispronunciations and frantic hand gestures. This is the same cartoonish, brilliant Žižek who has reached vast audiences with his writing (more than 50 books) and his live shows. Žižek, clearly, is not your average Slovenian philosophy professor.

As Fiennes watches our scene replayed on a monitor, Žižek shambles up, still in his pyjamas. "Sophie, we must have time today for me to re-enter the tank." I notice, off in a corner, a high-sided water tank. It was used yesterday to recreate Titanic, with Žižek in a lifeboat. The water has acquired a scum overnight, but Žižek is adamant: "Today I must be in the water."

Fiennes, tall and unflappable, explains that her star has decided the movie must have an underwater finale. "He's desperate for it to be a proper film with a proper happy ending," she smiles. "He's just not sure what it is yet."

Satisfied there will be time to take a dip, Žižek resumes the monologue he keeps up when in company. To be around him is to be privy to a gregarious, open-ended address on, well, take your pick: Shostakovich, cloud computing, industrial rock band Rammstein, Malian cotton production, Icelandic crime fiction, the 1,200-page opus on Hegel he's just finished writing, all punctuated by a supply of dirty jokes involving married couples in the former Yugoslavia.

"I have two questions for you," he says to me. "Do you ever receive bribes from film producers to favourably review their films, and did you ever interview the American actress Liv Tyler?" As anyone who's read Žižek's madly interwoven works of theory will know, film is his prism: rare is the argument he can't illustrate with a reference to Hitchcock. But then it may be the perfect art form for a thinker who treasures contradiction, a medium of simple surfaces and hidden depths that can be both trashy and transcendental.

A recent visit to China allowed him access to a vast range of dirt-cheap pirate DVDs. "They are really such wonderful quality now. Flawless! I bought Antonioni, I bought Woody Allen." He segues into the links between Zhang Yimou, director of 2004's House of Flying Daggers, and the Chinese government; his respect for film-maker Zack Snyder (Watchmen, 300); and his suspicion of European art movies. "Even Bergman, who made many films I like, when I see his Cries and Whispers, I become Goebbels. 'Just burn this!' Gah!"

Unsurprisingly, Žižek's soliloquies to camera, while based on passages from his books, leap off in all directions. But today the clock is ticking. Apart from Seconds and Titanic, the schedule also requires a re-creation of The Dark Knight, with Žižek addressing Batman in a Gotham interrogation room. As the crew prepares, he regales them with gags about Balkan foreplay (the man wields a rock). Then hush, and action.

With his gaze fixed on a stand-in caped crusader, he begins: "In psychoanalytic treatment, it is crucial the analyst and his patient are not confronted face to face – because psychoanalysis knows the face is a lie." Then he's off, citing George Bush's notorious glimpse of Putin's "soul" and critiquing The Omen, before dissecting the use of white lies among colleagues.

The connections keep coming. He reviews the brutal logic of the Iraq war, the silence of economists before the financial collapse – and then glides back to Christopher Nolan's movie. "The gravest implication about The Dark Knight is that it elevates the lie into the principle of society, as if for society to operate at all, there has to be a lie, as if to tell the truth must automatically mean chaos –" At this point, Batman stumbles forward. There will have to be another take.

Žižek smiles resignedly. At 15 he wanted to direct films; at no point did he long to be an actor. Despite his geniality, he insists he's no natural performer. "Never in my life did I dance, and never did I sing. It is too obscene for me psychologically. Even in private, I am unable. And yet here I am, singing and dancing."

Leftwing multiple orgasms

Fiennes compares Žižek's thought process to a musician unable to stop playing. The film-maker has documented many mercurial subjects: dancer Michael Clark, artist Anselm Kiefer, fellow director Lars von Trier. But with Žižek, beneath his near-constant teasing, there's clearly mutual respect. He's the star, but the film is hers: before shooting, she combs his work for possible scenarios; afterwards, she edits hours of footage; in between, she wrangles him. "It's always collaborative. He needs to know I won't bully him. Making The Pervert's Guide to Cinema was a huge controlled experiment, and so is this."

At 62, Žižek does tire. But even as he takes a rest, he stares at the water tank. You might think the demise of global capitalism would have already given this Marxist his perfect closing scene, He says not: "I am a communist, but I am not an idiot. What to me is tragic in all these events – that give old-fashioned leftists multiple orgasms – is where is any concrete principle of reorganisation? What is new? Because that is what is needed. But I do not see it. Liberal democratic capitalism is approaching its limit, and in its place we need large, coordinated social actions. Otherwise the future will resemble one of my favourite films, Terry Gilliam's Brazil. Not the old fascism, but a fascism of buffoons. I am not a catastrophist, but also I am not a Marxist who thinks history is on our side. No!"

When the Titanic scene finally happens, it's so late I have to go. Žižek hovers in a corridor, preparing to change into a wetsuit, having been talked out of doing the scene in his underwear. I tell him I hope he finds his happy ending. He nods energetically. "I would say the same to you, but you already have yours – you are leaving!"

• The Pervert's Guide to Ideology will be released next year.