During the winter of the scholastic year 1905-1906, the author delivered a course of lectures, on the subject of which this book treats, before the Oriental Seminary of the Johns Hopkins University. At the conclusion of the course, some of the students expressed the desire of possessing the lectures in permanent form. Acting on this wish, on the consciousness that few people know anything of the contribution of Jews to the science of Biblical criticism, and on the hope that a word on the subject may be welcome, the author herewith presents the results of his investigation in popular form. Footnotes, giving more exhaustive explanations, have been omitted, because lacking in interest for the majority of readers. Not all Biblical commentators have been treated in this book, as not all are of equal importance. Only such have been considered as represent distinct schools of criticism. - W. R.