Using previously unpublished material, including private correspondence, Shapiro (Judaic Studies, U. of Scranton, Pennsylvania) discusses the many aspects of the life and thought of Rabbi Weinberg (1884-1966), an important ideologue of modern Orthodoxy. The author focuses on his evolving philosophical orientation, from his early years in Poland, his years in Germany, Lithuania, and Poland from WWI through the Nazi era, and his post-war years in Switzerland.