The opening scenes of The Exorcist take place in a pre-Saddam Hussein Iraq, far from the townhouse in Georgetown where the bulk of the movie is set. It’s a curious introduction; all the dialogue is in Arabic, and nothing really happens. A boy runs across an archeological dig and summons an elderly man. The man follows the boy back and unearths a medallion of St. Joseph, the patron saint and protector of the Catholic Church, bearing a Latin inscription that translates as “pray for us” (not the usual thing one finds in ancient archeological digs). Digging further, the old man pulls out a dirt encrusted figurine of a grotesque head. As he clears the dirt from the figure, his expression subtly changes from one of curiosity about the relic to one of dread. It is evident in his eyes that he recognizes what has been uncovered. The rest of this prologue follows the old man through the streets of Iraq. He takes a nitroglycerin pill for his heart, his hands shaking violently, as he makes his way. A one-eyed man hammers at an anvil. An elderly woman, dressed in black mourning clothes, nearly runs him over in her horse-drawn carriage. Finally, he arrives at an archeological site where two men with guns rush out and are dismissed by a wave of the man’s hand. A third man stands to the side, watching him with interest, but does nothing. Two dogs, one white with black spots and the other black with white spots, start to fight, snarling, growling, and snapping at each other in a brutal dance, while a third dog, also white, circles. The camera pulls back to a wide shot of the man standing on a promontory, face to face with a statue of a winged figure that shares the same grotesque visage as the figurine. The winds howls as the old man and the statue face each other like the last two pieces of a chess game. End scene.

It’s a master class in filmmaking, powerful, evocative, and disturbing. It says little (there isn’t a lot of dialogue in these first few minutes), but foreshadows much. These characters will all turn up later in different guises. Father Damien Karras is half-blind to his faith but still relentlessly hammering away as he seeks the truth. Chris McNeil is a helpless passenger in a life that’s careening out of control, mourning the living death of her daughter Regan. Regan’s physician and psychiatrist, and all they represent, rush to the scene but are summarily dismissed because their science is of no use here. Lieutenant William Kinderman, the policeman who is ever watchful, stands apart from the action, separated by his distance from the truth of what is happening in that Georgetown townhouse. Father Merrin, the old man in Iraq, the good man who is stained by sin, fights to the death with the demon Pazuzu, while Father Karras assists.

One of the things that makes The Exorcist so remarkable is this attention to imagery and symbolism. The sound of the demon leaving Regan is manipulated audio of pigs squealing, tying the scene to the Bible, where Christ exorcised a man by sending the demons into a herd of swine. Father Karras is considering leaving the priesthood as he and his bishop sit in a Georgetown bar, while the background music is “Ramblin’ Man” from the Allman Brothers. “I think I’ve lost my faith…I want out of this job,” says Karras as the song of a life on the road is turned into a prayer for understanding: “Lord, I was born a rambling man…/When it’s time for leaving/I hope you’ll understand.” Unsure of his faith and unsure of his role in the Church, Father Karras is literally running in circles, around a track, when he is first pulled into the orbit of the McNeils by Lieutenant Kinderman, the circumstances that will renew his faith and provide his ultimate redemption. But what really sets the film apart is that The Exorcist is a profound meditation on the battle of good vs. evil gussied up with gross out special effects, obscene language, and the most shocking visuals anyone had ever seen in a movie at that time (some of these visuals are still shocking over 40 years later).

Even more unusual for a horror film, or any film made after the 1950s, is that the good is represented unambiguously by the Catholic Church. There’s no ironic detachment, no Christian bashing. The heroes are not non-denominational ministers waving Bibles in the air and reading out-of-context quotes from the New Testament, or New Age clerics combining religions into a “spiritual” soup to defeat a non-specific agent of evil; the heroes are two Catholic priests, reading verbatim from the Catholic rite of exorcism and supported fully by the Church hierarchy. It’s a script that only a devout Catholic like William Peter Blatty could have written. There’s an ancient evil unleashed in the world, the ne plus ultra of evil, and the only thing standing in its way is the Catholic Church, armed with nothing more than an ancient ritual, holy water, communion wafers, and the compelling power of Christ. The parade of demonic horrors that is The Exorcist may be the most pro-Catholic movie ever made. Indeed, in her typically snooty review, the dyspeptic critic Pauline Kael called The Exorcist “the biggest recruiting poster the Catholic Church has had since the sunnier days of Going My Way….”

At the center of the movie is Jason Miller’s portrayal of Father Damien Karras, a Jesuit priest and psychologist. He’s burned out from listening to the confessions and troubles of his fellow priests. He’s racked by guilt because he’s living in Washington D.C. while his elderly mother is alone in New York. Miller, a Pulitzer Prize-winning playwright and stage actor in his first film role, plays Karras perfectly. It’s remarkable how tired he appears through the film, as if the weight of the world is on his shoulders. He doubts the idea of possession, at one point telling Chris that to get an exorcism you’d first need to get a time machine. Even when the Church hierarchy asks if he’s “convinced” the possession is genuine Karras responds, “No, not really” before explaining that his conclusion is based on a rational judgement of the criteria as indicated by the Church.

Karras is given the okay to aid in the exorcism, but the main role will be filled by Father Lancaster Merrin, last seen in the archeological ruins of Iraq. Max Von Sydow’s Merrin is quiet and gentle, but spiritually strong. He’s confronted this situation before, in an exorcism that “lasted for months” and “damn near killed him” according to the bishop, and knows what he will be facing. In his first meeting with Karras, Merrin gently but firmly rebukes the younger priest. Karras uses the language of psychology, explaining “the case”, and that the girl “is convinced” there are three entities inside of her. Merrin cuts him off: “There is only one,” he says. When Karras opines that he thinks he should explain the specifics of what he’s seen, Merrin is even more curt: “Why?” Psychology as an aid for the girl is useless. But psychology as a weapon for the demon is not. “The demon is a liar…but he will mix lies with the truth to attack us. The attack is psychological, and powerful.” That is certainly what the demon does to Karras, appearing to him in the guise of his recently departed mother, speaking in her voice, asking sadly why he left her. The appeal is to Karras’s guilt, and it shakes up the priest to the point where he can’t continue.

The battle at the heart of the movie is timeless. The modern gods of science and psychology are useless. The outcome of the fight is never really in doubt. The only question is whether or not the demon can stand long enough to achieve its purpose.

The film also differs from the rest of the genre in the reasons for the possession of young Regan McNeil. Horror films are filled to bursting with ghosts seeking vengeance, demons unleashed to kill as many people as possible and create as much havoc as they can, monsters avenging the destruction of their habitat, self-aware robots looking to overthrow their creators, and mad scientists out to rule the world. The demon’s motivation in The Exorcist is far more subtle, and far more profound. The demon is not seeking world domination. Its purpose is not to kill the possessed girl, though her death is a perfectly acceptable part of the desired outcome. The purpose of the demon is the eternal purpose of the Devil in Judeo-Christian theology: to tempt man away from God. When asked by Karras why this innocent child would be victimized this way, Merrin responds “I think the point is to make us despair. To see ourselves as animal and ugly. To make us reject the possibility that God could love us.” The target of the demon is not the girl; the target is God. The demon’s purpose is not carnage or dominion or, in fact, any earthly desire; it is to plant a voice in your head that makes you believe you are unworthy of God’s love and, thus, to sever the bond between God and His greatest creation. The demon does not seek to gain; it seeks to destroy humanity’s relationship with God. Once the break from God is accomplished, the demon succeeds. By casting people into the sin of despair and the rejection of God, the demon damns souls and undermines the meaning of the Crucifixion and Resurrection. The battle is between God and the Devil here: the little girl and the priests are merely pawns.

Part of the genius of The Exorcist is that it is a genuinely philosophical work about the nature of man and God, yet never fails to deliver all the shocks of a traditional horror movie. Whether it’s the swiveling head, the projectile vomiting, the poignant but still creepy words “help me” that appears on Regan’s torso, the sexualized desecrations in the church, or the demonic visage that intermittently pops into the frame for less than a second, The Exorcist‘s visual language is horrific and terrifying. The infamous scene of Regan masturbating with a crucifix (though a better description would be “stabbing herself repeatedly and brutally”) is one of the most disturbing scenes ever filmed. But even as the horrors escalate and grow closer together the film never strays from the humanity of the characters. Even Regan, devolved from a pretty pre-teen into a barely recognizable nightmare strapped to a bed, remains a little girl who is trapped inside of herself.

The Exorcist ends with hope, also an anomaly among the biggest horror films of the last fifty years, many of which end with evil triumphant (Rosemary’s Baby, The Omen) or with evil merely set back but still threatening (Halloween, The Ring, the endless string of Jason, Freddy, Pinhead, and Jigsaw movies). Too much recent horror fiction, in both books and movies, is nihilistic. Filmmakers and writers come up with ever more elaborate ways of killing off impossibly good-looking twentysomethings. There are three deaths in The Exorcist: one gruesome murder that is discussed but never seen, one natural death (also off-camera, but shown after the fact), and one Christ-like sacrifice that saves a girl and redeems a sinner. Compare this to over 40 lovingly detailed on-screen deaths in the five Final Destination movies, or the nearly 40 on-screen deaths in four Scream movies. In The Exorcist, the deaths advance the plot. In too many other horror movies, the deaths are the plot. It is the firm belief that good will triumph over evil, the unashamed celebration of Catholicism, the philosophical undertones, and the striking attention to imagery and symbolism that make The Exorcist a film of the first rank. Add in the relentless pacing, Oscar-worthy acting (Linda Blair, Jason Miller, and Ellen Burstyn were nominated…the film itself got ten nominations, winning one for Blatty’s script), a director at the peak of his ability, and the idea that even the worst horror can have meaning in the world, and you’ve got a classic.