Orthodoxy in Judaism is the attempt to maintain the Jewish group by means of the religious and customary behavior which has operated successfully for that end since the destruction of the Jewish commonwealth in 70 A. D. It is conservative; it finds its chief values, not in the national, but in the religious life; and it endeavors to hold its group intact by a traditional ritual which possesses a profound emotional appeal and establishes certain habits of life. It is the appeal to loyalty and to group stability, and parallels similar conservative movements in many Christian denominations, though with the stronger urge of a longer and more bitter history of persecution. Finally, there is a theory of group adaptation, best developed institutionally by the reform and conservative synagogs, but also in many non-religious organizations—social clubs, Young Men’s Hebrew Associations (the very name an imitation), labor unions, and the like. Not that these various parties are identical; as a matter of fact, they have practically nothing in common except the incorporation in their philosophies of the two elements—Jewish tradition and modern adaptation; but the conservative and reform statements—of adaptation, of tradition, and of the relation between the two—present profound differences both in theory and in practical details of application. This adjustment is not as yet entirely successful, but has developed a number of useful responses, by which Jews are managing to preserve their group identity and at the same time to enter as constituent members into the American group mind. It is still in a transition period, but the synthesis is being worked out clearly enough for our purposes. In the synagog it involves the reading of part of the prayers in English, as well as Hebrew, the beautification of the service by modern music, both vocal and instrumental, the incorporation of a sermon in English, a modern system of religious education, and a development of the social life of the young people by clubs, classes and recreational means. Without the synagog, it involves a type of “Modernism,” intellectual and moral. Even in the group which endeavors to be most orthodox, it is finding its way in the form of social surveys, modern methods in Hebrew education, and some sort of working compromise with the community custom of Sunday observance, the English language and the eating of non-kosher food. The nature of this adjustment is clear from the fact that every separate item has a different solution. The great majority of Jews work on the traditional Sabbath, due to the combined social and economic pressure; they universally are adopting English as their daily speech, but the majority of them have not yet admitted English into the ritual of the synagog; all those who really care to do so maintain the Jewish dietary laws in their own homes, though very few (comparatively) go so far as to refuse to enter a restaurant where the dishes are washed