O'Brien's book "A Landscape with Dragons: The Battle for Your Child's Mind" – described as controversial by its publisher – presents his concern that contemporary children's literature and culture has strayed from Christian ethics to a more pagan ideology where good and evil is not strongly defined. The book features O'Brien's examination of fantasy works ranging from C. S. Lewis' "The Chronicles of Narnia" and J. R. R. Tolkien's "The Lord of the Rings" to Anne McCaffrey's "Dragonriders of Pern". One of the book's central claims is that any story in which dragons are presented sympathetically rather than as forces of evil is implicitly anti-Christian because of the traditional use of the dragon as a symbol for Satan.