xM ffordecai M. Kaplan's concept of Jewish civilization has received more than its share of ink from American Jewish historians, and rightly so. Kaplan not only proposed the most original and far-reaching program for revitalizingJewish life in America but also offered the most penetrating analysis of the challenges facingJews in twentieth-century America. Yet, for all the attention paid to Kaplan's innovative notion ofJewish civilization, considerably less interest has been expressed about his description of American civilization. After all, the foundation of Kaplan's philosophy rested on the assumption that Jews lived in two civilizations, one Jewish and one American, and he insisted thatJews could and should be full participants in both. It is not surprising thatJewish historians have devoted the bulk of their scholarly attention to exploring Kaplan's concept of Jewish civilization, but a closer examination of the American portion of his program reveals Kaplan's great faith in the promise of American democracy as well as just how much he believed Jewish fate to be bound up with the security and continued improvement of the American democratic system. Kaplan's Jewish civilization ultimately rested