It's easy to sell good news like this, and the authors confidently rely on classic fallacious arguments. They argue by declaration, which is what makes the books so amusing. In matter-of-fact, authoritative tones, the authors tell us how plants and human beings exchange energy - or they describe what angels look like, whether or how they're sexed, how they communicate with human beings, and how they differ from ghosts. Readers might be expected to wonder, How do they know?