While The Exorcist was already a best-selling book, the motion picture version made it a cultural phenomenon.

The motion picture, scripted and produced by Blatty and directed by William Friedkin, debuted the day after Christmas, 1973. Controversially released with an R rather than an X rating, it was picketed by churches, while people lined up for hours to get in. Reports spread—no doubt exaggerated, but based on reality—of people fainting and vomiting in the theaters; soon, there was also a rash of people fearing that they themselves were possessed. Commentators such as Father Richard Woods and others toured campuses, lecturing on exorcism and the supernatural, while theology was revived as a popular topic.

The acting drew general praise, even from critics who disliked the movie as a whole. The most controversial casting, of course, was allowing a young girl to act in a motion picture...