This book is filled with images that go a long way toward revealing the processes that underlie the phenomena that we call ghosts or spirits. Only one of the people shown in four pictures on this back book cover is unlikely to be known to the curious reader. The other three are well-known historic personages. It may not be so easy to work out who may be represented here when these images are looked at for the first time, but they are all ghosts-of a kind. By using special photographic techniques developed by a psychic medium and combining these techniques with some theoretical ideas based in...