William Friedkin’s 1973 masterpiece The Exorcist, one of the few horror films to have ever been nominated for Best Picture at the Oscars (to date The Silence of the Lambs is the only horror winner of the award) was re-released in 1999. when I was 16. I was underage, so I had to sneak in. The trailers back in the early digital age of cinema were creepy and utterly enthralling.

I remember two things vividly about the film. One, it gave me nightmares for years (so much so I felt I was being followed home by invisible demons) and two, during the screening in Bromley cinema half of the drunk, twenty-something audience were laughing during the scene where Regan, possessed by the African wind demon Pazuzu masturbates bloodily with a crucifix before her head rotates 180 degrees. I couldn’t understand why they were laughing. That scene horrified me. I imagine it was something to do with the analogue effects, which, in the age of The Matrix (released the same year) they couldn’t seem to connect with, and found slow and boring.

Aside from The Passion of Christ, Friedkin’s still-terrifying film is the most Catholic film ever made. (It is also the most Satanic unless you count Rosemary’s Baby the commercial success and notoriety of which ensured the green light for the movie.) Both directors have had a bipolar relation with both the sacred and profane, committing and saying awful things. Friedkin’s abuses on the set of the film were documented in Peter Biskind’s classic nonfiction tale of 70’s American cinema Easy Riders, Raging Bulls where the director told Biskind: “There’s a darkness in my soul, a profound darkness that is with me every waking moment.”

Charlie Manson and the Altamount tragedy had ended the sixties, and there were queues round the block for the film in 1973. With these atrocities and the atrocity of Vietnam, America was ready for a film of this intensity. Critic Pauline Kael wrote concernedly “to take children would be madness”.

From my extensive chats with psychiatrists since, The Exorcist has inspired literally hundreds of psychiatric admissions (although now it’s usually Tom Six’s The Human Centipede). Linda Blair needed extensive therapy and even received death threats from psychotic people believing she was the Devil.

Friedkin states in the 1999 introduction that his movie was seriously trying to convince the audience of supernatural forces in the world, both good and evil. As philosopher John Gray wrote: “while atheists may call themselves freethinkers, for many today atheism is a closed system of thought. That may be its chief attraction. When you explore older atheisms, you will find that some of your firmest convictions – secular or religious – are highly questionable. If this prospect disturbs you, what you are looking for may be freedom from thinking.”

This explains the laughter at the cinematic sexualised assault of a child in Bromley cinema by a demonic force, an innate atheism that has been developing for at least two decades. Atheism is group think, and if The Exorcist doesn’t make you question the nature of both God and the Devil, you are unable to understand its message. The psychiatric priest Father Karras tells Father Merrin that he has identified at least three personalities within the demon.

Merrin gravely replies: “There is only one.”

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