If ever a director’s decision to cast an actor based solely on looks could be excused, it would be Pier Paolo Pasolini’s choice of Terence Stamp for the lead in 1968’s Theorem. As the mysterious, nameless, selfless houseguest of a well-off Milan family, Stamp (above) combines the insouciance of Malcolm McDowell in A Clockwork Orange with a passive saintliness appropriate to Pasolini’s satirical intent. Stamp didn’t even have to be able to speak Italian — his character barely talks, and everyone’s dubbed anyway.

Somewhere between the profound and the Pythonesque, Theorem ticks all the boxes for a 1960s European art film: allegorical Christ figure exposes middle-class hypocrisy with his sexual magnetism and non-linear narrative. The whole family’s up for a bit with Our Terry, apparently. Mum, dad, son, daughter, he seduces them all, even the pious housekeeper (amusingly reminiscent of Mrs Doyle from Father Ted). Staggeringly rich in imagery and ideas, Theoremis nevertheless barely competent technically. Pasolini had evidently rejected things like continuity, focus or holding the camera straight as more bourgeois concepts to be challenged.

Though Theorem was banned for obscenity on its release, the BFI’s new uncut DVD is rated only a 15. Society is obviously no longer at risk.