It’s a classic moment in cinema: a car pulls up to a dark house and from the vehicle steps a man in a dark coat, a hat, and a suitcase - he steps forward into a pool of light that’s coming from the bedroom window of the possessed girl, Reagan; I’m, of course, talking about The Exorcist. This moment has become iconic but the practice of actual exorcism has mostly gone out of fashion, performed, rarely, by the Catholic Church (more-so by other denominations but those are not th