xv Preface This encyclopedia is dedicated to supersti- tious, supernatural, and discredited beliefs held in a variety of civilizations and societ- ies from the ancient world to the nineteenth century, although there is also some discus- sion of the twentieth and twenty-first centu- ries. It does not, however, include the large body of supernatural beliefs central to organized religions, although religious top- ics do come up in passing. Obviously, no book could cover the vast range of beliefs held by human societies across the globe throughout thousands of years of recorded history. A whole library would be full to bursting. What this book contains is a selection of some of the most important, interesting, influential, or simply bizarre beliefs held by people from pole to pole. The emphasis is on the period before 1800, as in the nineteenth century the Industrial Revolution, the spread of mass literacy in many societies, and imperialism wrought vast changes on traditional cultures and beliefs. However, some beliefs documented in the period after 1800 are included when appropriate. The encyclopedia was written in the age of COVID. Writing it would have been impossible without the internet, which gave me access to hundreds of documents and sources at a time when I could not visit libraries. I express appreciation to my fam- ily for providing support, as well as to the Gelman Library of George Washington University, my editor Kevin Downing, and Michael R. Lynn.