The book doesn’t lack insight and McCabe is surely right that this was one of the most influential movies of the early 1970s. It has become a frame of reference on its own and it has defined, in large measure, what people believe about demonic possession. One of the quotes from McCabe’s treatment however, uses the phrase “metaphysical unknown” to explain why the film retains its power to scare, and there’s a great deal of wisdom in that assessment. Fear of the unknown, of course, is prime real estate for horror, and one of the most interesting things about demons is how little the Bible, or other ancient texts, really says (or say) about them. They are an embodiment of the unknown that can take over a person and make her somebody else. But it’s that metaphysical that’s really scary.
As we continue into a time of less and less that remains unclaimed by scientific theory, those metaphysical unknowns continue to lurk and to frighten. Maybe it’s the concept of the metaphysical itself that scares—can there really be something larger, more intelligent than us? The human psyche bruises easily, and we don’t like to be reminded that we lack the control we suppose we have each day. The metaphysical challenges all that. Since it refuses to submit to empirical verification, it remains unknown. A great many people interpret this as the same as not believing in it. Every once in a while, however, a powerful statement such as The Exorcist comes along. Few people thought about demons before William Peter Blatty’s novel and subsequent film. Then the world was full of them again. Requests for exorcisms are on the rise, and the metaphysical unknown haunts us now as much as it ever has.