This essay identifies five paradigms that are basic to understanding the historical emergence and uses of the generic idea of “religion” in the Christian cultures of Europe and America. The spread of this concept has been sufficiently thorough in recent centuries as to make religion appear to be a “social fact,” to use Durkheim's phrase, rather than so many cultural expressions and different social practices. The supremacy of Euro-American culture—and an academy still saturated with Christian ideas—has enjoined other cultures and forms of religiosity to conform to this idea of religion; for these cultures contentment with the status quo can vie with the anxieties of influence, including “modernization.” The key paradigms discussed are the following: Christianity as the prototype; religion as the opposite of reason; the modern formulation of “world religions”; the cultural necessity of religion; and critical analysis of the Western “construction” of religion. These paradigms demonstrate the limits on theoretical variety in the field, the difficulty in making real changes in set ways of thinking, and productive foci for interdisciplinary methods of study.