Boorman was selected as Director for Exorcist II: The Heretic (USA, 1977), a move that surprised the industry given his antipathy to the original film. Boorman declared: "Not only did I not want to do the original film, I told the head of Warner Brothers John Calley I'd be happy if he didn't produce the film too." The original script by Broadway Playwright william Goodhart was intellectual and ambitious, based around the metaphysical nature of the battle between good and evil, and specifically the writings of Catholic theologian Pierre Teilhard De Chardin, "I found It extremely compelling. It was based on Chardin's intoxicating Idea that biological evolution was the first step In God's plan, starting with inert rock, and culminating In humankind." Despite Boorman's continued rewriting throughout shooting, the film was rendered incomprehensible. The film, released in June 1977, was a critical and box office disaster. Boorman was denounced by author william Peter Blatty, the author of the original novel The Exorcist, and william Friedkin, Director of the first Exorcist film. Boorman later admitted that his approach to the film was a mistake. The Heretic is often considered not just the worst film of The Exorcist series, but one of the worst films of all time.