This movie is a sign that a supernatural theme can be taken from a coherent point of view without turning fantasy, is a perfect balance that I think was one of the factors in the success of this movie.
furthermore, the co-relationship between religion, science and the situation is very good because it does not dull the film or tape becomes full religious
This is classified like an horror movie, but most than an horror movie, I think the exorcist gave rise to what would be the future of this genre to our times.
you maybe doesn't feel super scared but the concept of terror and development its pretty good and a real jewel for our film history.