The idea of world religions expresses a vague commitment to multiculture alism. Not merely a descriptive concept, world religions is also a particular ethos, a pluralist ideology, a logic of classification, and a form of knowledge that has shaped the study of religion and infiltrated ordinary language. In this ambitious study, Tomoko Masuzawa examines the emergence of world religions in modern European thought through a close reading of a variety of sources as early as the seventeenth century. Devoting particular attention to the relation between the comparative study of language and the nascent science of religion, she demonstrates how new classifications of language and race caused Buddhism and Islam to gain special significance as these religions came to be seen in opposing terms - Aryan on one hand and Semitic on the other. Masuzawa also explores the complex relation of world religions to Protestant theology, from the hierarchical ordering of religions typical of the Christian supremacists of the nineteenth century, to the aspirations of early twentieth-century theologian Ernst Troeltsch, who embraced the pluralist logic of world religions and by so doing sought to reclaim the universalist destiny of European modernity.