The great nineteenth-century social thinkers argued that the rise of modern industrial society entailed the decline of religion. Modernization has indeed involved the rise of rational-bureaucratic states and the gradual displacement of ecclesiastical authority with that of professional and technocratic elites. But in recent decades, a resurgence of religiosity and religious fundamentalism seems to have reversed the global trend toward secularization. Drawing on extensive worldwide survey data, Norris and Inglehart try to explain this development by advancing an "existential security" thesis: the experience of people living in weak and vulnerable societies heightens the importance of religious values, whereas the experience of people in rich and secure societies lessens it. Indeed, they find that in most developed countries church attendance and the authority of religious figures have continued to decline (although the United States is a bit of a laggard because of social inequality and the massive immigration of people with traditional world-views). In contrast, poor countries are not secularizing-and they contain a rising share of the world's population. The authors predict that this "expanding gap" between sacred and secular societies will have serious consequences for world politics, but they do not venture specific guesses about what is to come.