Though the writer has throughout been aware of the difficulties inherent in his task, yet he is also conscious that he has sometimes succeeded in removing them only by eluding them. In parts, when the matter to be treated was unyielding, it became necessary to dwell on side issues, or fill up gaps and replace obscurities by legends and hypotheses. The object in view being a book popular in character and accessible to all, technical discussions had to be eschewed. Many knotty points had to be brushed aside lightly, and the most debatable points passed over in silence. These are the sacrifices to which one must resign himself, though it requires self-restraint to do it consistently. The reader may, therefore, not expect to find new data in these pages, new facts and texts not published before. If the book has any merit, it is that it presents the actual state of knowledge on the subject, and the author anticipates the charge of plagiarism by disclaiming any intention of producing an original work. Recondite sources have not always been referred to, in order not to overload a text which at best is apt to tax the reader's powers of attention. Such references and special remarks as were deemed necessary have been incorporated either in Notes placed at the end of the book, or in an Appendix containing a bibliography. There the works are mentioned to which the author is chiefly indebted, and which his readers may profitably consult if they desire to pursue the subject further. The author desires to express his appreciation of the work of the translator, whose collaboration was all the more valuable as the revision of the book had to be made, after an interval of almost two years, under most unfavorable conditions, aggravated by the distance between the writer and the place of publication. The readers will themselves judge of the skill with which the translator has acquitted herself of her task, and the author gladly leaves to her the honor and the responsibility for the translation. But how can I express all I owe to M. Israel Levi, my honored master? Without him this work would never have been begun, without him I should never have dared carry it to completion. I have contracted a debt toward him 'which grows from day to day, and I discharge but the smallest portion of it by dedicating this volume to the memory of his never-to-be-forgotten father-in-law, the Grand-Rabbin Zadoc-Kahn. M. Zadoc-Kahn made a name for himself in Jewish letters by his <I>Etudes sur le livre de Joseph le Zelateur,</I> dealing with one of the most curious domains of that literature in which Rashi was the foremost representative. One of his last public acts was the appeal which he issued on the occasion of the Rashi centenary. It is not a slight satisfaction to me to know that these pages passed under his eyes in manuscript. M. LIBER CHALONS-SUR-MARNE, March, 1906 CONTENTS