I recommend to friends that they should read anything by Mary Roach (and Malcolm Gladwell but that's another story) and have been quoting from this book a lot since reading it. This book explores the history of how science has been used to investigate or explain "spiritual" phenomenon such as reincarnation, mediums communicating with the dead, near-death experiences, where the soul lives in the body or when it enters the body for that matter. Very interesting. Aristotle did experiments with semen which he believed a whole and complete person lived in somewhere and that the egg produced by women was just nourishment for growing that person but the debate was when did the soul enter the body. An early Jewish doctor claimed to have found an indestructible bone that the soul lived in that until more modern anatomy practices were developed was proved never to have existed. A current experiment on haunted places in London proposes that those queer feelings one feels (chills, tingling skin, queasiness) may in fact be infra-sounds or sound vibrations that we can't hear but rather feel. Roach even investigates an actual court case in which the son of a deceased farmer claimed to have been visited by the ghost of his father who pointed him in the direction of a new will he had written that equally divided his property between all his sons not just the one who had inherited everything. She employees a handwriting expert on the two wills and makes an interesting discovery. And poor mediums in the late 1800s were subjected to some really crazy experiments to determine if they were authentic.