Franz Cumont, born January 3, 1868, and educated at Ghent, Bonn, Berlin, and Paris, resides in Brussels, and has been Professor in the University of Ghent since 1892. His monumental work, _Textes et monuments figures relatifs aux mysteres de Mithra_, published in 1896 and 1899 in two volumes, was followed in 1902 by the separate publication, under the title _Les Mysteres de Mithra_, of the second half of Vol. I, the _Conclusions_ in which he interpreted the great mass of evidence contained in the remainder of the work. The year following, this book appeared in the translation of Thomas J. McCormack as _The Mysteries of Mithra_, published by the Open Court Publishing Company. M. Cumont's other work of prime interest to students of the ancient faiths, _Les religions orientales dans le paganisme romain_, appeared in 1906, was revised and issued in a second edition in 1909, and is now presented in English in the following pages. M. Cumont is an ideal contributor to knowledge in his chosen field. As an investigator, he combines in one person Teutonic thoroughness and Gallic intuition. As a writer, his virtues are no less pronounced. Recognition of his mastery of an enormous array of detailed learning followed immediately on the publication {vi} of _Textes et monuments_, and the present series of essays, besides a numerous series of articles and monographs, makes manifest the same painstaking and thorough scholarship; but he is something more than the mere _savant_ who has at command a vast and difficult body of knowledge. He is also the literary architect who builds up his material into well-ordered and graceful structure. Above all, M. Cumont is an interpreter. In _The Mysteries of Mithra_ he put into circulation, so to speak, the coin of the ideas he had minted in the patient and careful study of _Textes et Monuments_; and in the studies of _The Oriental Religions_ he is giving to the wider public the interpretation of the larger and more comprehensive body of knowledge of which his acquaintance with the religion of Mithra is only a part, and against which as a background it stands. What his book _The Mysteries of Mithra_ is to his special knowledge of Mithraism, _The Oriental Religions_ is to his knowledge of the whole field. He is thus an example of the highest type of scholar--the exhaustive searcher after evidence, and the sympathetic interpreter who mediates between his subject and the lay intellectual life of his time.