The writer has attempted in this volume to take up a few of the most characteristic points in Jewish doctrine and practice, and to explain some of the various phases through which they have passed, since the first centuries of the Christian era. The presentation is probably much less detached than is the case with other volumes in this series. But the difference was scarcely avoidable. The writer was not expounding a religious system which has no relation to his own life. On the contrary, the writer is himself a Jew, and thus is deeply concerned personally in the matters discussed in the book.