Through the publication during the past fifty years of a large number of Arabic sources for the study of Moham medanism, before that accessible only in the manuscript collections of European libraries, our knowledge of the origin and course of Islam, and more particularly of the development of Islamic theology in the various countries to which the religion spread, has been greatly extended. Hand in hand with the publication of important Arabic texts has gone the critical study of the material in the form of monographs, and of papers in the transactions and journals of learned societies. Naturally, European scholars — in Germany and Austria, in England and France, Holland and Italy — have been the chief workers in this field, though during the last decades some valu able contributions have been made by American scholars. The strong impetus to Arabic studies, the result of which is seen in the considerable body of scholars now devoting themselves to the subject, may be traced back to the distinguished French Orientalist, Silvestre de Sacy (1758-1838) and to his pupil Heinrich Leberecht Fleischer (1801 for many years Professor of Oriental Languages at the University of Leipzig, and who had the distinction of training a large proportion of the Arabic scholars of the following generation. Other notable Arabists of the middle of the nineteenth century were Gustav Wilhelm Freytag of the University of Bonn (17 88-1861) also a pupil of de Sacy, Ferdinand Wuesten feld (1808 particularly active in the publication of Arabic texts, Heinrich Ewald (1803-1875) of the Uni versity of Gottingen, and Reinhart Dozy of the Univer sity of Leyden (1820 while coming closer to our own days we have the late Professor M. J. De Goejeviii mohammed and islam.