Do not look to find in this volume a history of occultism or a methodical monograph on the subject. The author has no other aim than to tell as simply as possible what he learned in the course of some years that were spent in these rather discredited and unfrequented regions. Contents: India; Egypt; Persia; Chaldea; Greece before Socrates; Gnostics and the Neoplatonists; the Cabala; alchemists; modern occultists; metapsychists; conclusions.