Everything has a pedigree. Everything, whether animate or inanimate, whether a thing of sense or a creation of the mind, every idea whether based on fact or the growth of a delusion, every truth and every error, has its pedigree. A pedigree is a line of ancestors, a chain of causes and effects, each link first an effect and then a cause. Rarely, if ever, is an effect the result of an isolated cause, but causes cross and interlace in such endless combinations, that novel effects are continually being produced.