There are two equal and opposite errors into which our race can fall about the devils. One is to disbelieve in their existence. The other is to believe, and to feel an excessive and unhealthy interest in them. They themselves are equqlly pleased by both errors and hail a materialist or a magician with the same delight. The sort of script which is used in this book can be very easily obtained by anyone who has once learned the knack, but illdisposed or excitable people who might make a bad use of it shall not learn it from me.