Lake monsters, yetis, UFOs, crop circles, guardian angels and visions of the Virgin Mary can all be described as apparitions, and Patrick Harpur weaves together an account of them in this book. He argues that only in the last three centuries or so - and only in Western culture - have such sightings become discredited. In popular mythology they are as active as ever, though spaceships and aliens may have replaced the Land of Faerie and its inhabitants. Drawing on Jung's "Collective Unconscious", Blake's "Imagination", and the Neoplatonic "soul of the world" among others, Harpur suggests that these phenomena can be made intelligible again by appealing to a different world-view, one which takes them seriously but not literally.