A specialized form of the frame is a dream vision, where the narrator claims to have gone to sleep, dreamed the events of the story, and then awoken to tell the tale. In medieval Europe, this was a common device, used to indicate that the events included are fictional; Geoffrey Chaucer used it in "The Book of the Duchess", "The House of Fame", "Parlement of Foules", and "The Legend of Good Women" (the last also containing a multi-story frame story within the dream). In modern usage, it is sometimes used in works of fantasy as a means toward suspension of disbelief about the marvels depicted in the story. J.R.R. Tolkien, in his essay "On Fairy-Stories" complained of such devices as unwillingness to treat the genre seriously. Lewis Carroll's "Alice" stories ("Alice's Adventures in Wonderland" and "Through the Looking-Glass") includes such a frame, but unlike most usages, the stories themselves use dream-like logic and sequences; most dream frames frame stories that appear exactly as if occurring in real life. The writer John Bunyan used a dream device in the Christian allegory Pilgrim's Progress and its sequel, explaining that they were dreams he had while he was in prison and felt God wanted him to write down. This worked because it made what might have been seen as a fantasy something more realistic and meaningful to others who believed as he did.