As to the _origin of polytheism_, I have adopted in the main Mr. Herbert Spencer’s remarkable ghost theory, though with certain important modifications and additions. In this part of my work I have also been largely aided by materials derived from Mr. Duff Macdonald, the able author of _Africana_, from Mr. Turner, the well-known Samoan missionary, and from several other writers, supplemented as they are by my own researches among the works of explorers and ethnologists in general. On the whole, I have here accepted the theory which traces the origin of the belief in gods to primeval ancestor-worship, or rather corpse-worship, as against the rival theory which traces its origin to a supposed primitive animism. As to the _rise of monotheism_, I have been influenced in no small degree by Kuenen and the Teutonic school of Old Testament criticism, whose ideas have been supplemented by later concepts derived from Professor Robertson Smith’s admirable work, _The Religion of the Semites_. But here, on the whole, the central explanation I have to offer is, I venture to think, new and original: the theory, good or bad, of the circumstances which led to the elevation of the ethnical Hebrew God, Jahweh, above all his rivals, and his final recognition as the only true and living god, is my own and no one else’s. As to the _origin of Christianity_, and its relations to the preceding cults of corn and wine gods, I have been guided to a great extent by Mr. J. G. Frazer and Mannhardt, though I do not suppose that either the living or the dead anthropologist would wholly acquiesce in the use I have made of their splendid materials. Mr. Frazer, the author of that learned work, _The Golden Bough_, has profoundly influenced the opinions of all serious workers at anthropology and the science of religion, and I cannot too often acknowledge the deep obligations under which I lie to his profound and able treatises. At the same time, I have so transformed the material derived from him and from Dr. Robertson Smith as to have made it in many ways practically my own; and I have supplemented it by several new examples and ideas, suggested in the course of my own tolerably wide reading. Throughout the book as a whole, I also owe a considerable debt to Dr. E. B. Tylor, from whom I have borrowed much valuable matter; to Mr. Sidney Hartland’s _Legend of Perseus_; to Mr. Lawrence Gomme, who has come nearer at times than anyone else to the special views and theories here promulgated; and to Mr. William Simpson of the _Illustrated London News_, an unobtrusive scholar whose excellent monographs on _The Worship of Death_ and kindred subjects have never yet received the attention They deserve, at the hands of unprejudiced students of religion. My other obligations, to Dr. Mommsen, to my friends Mr. Edward Clodd, Professor John Rhys, and Professor York Powell, as well as to numerous travellers, missionaries, historians, and classicists, are too frequent to specify.