One of the great 20th century theories of religion and society predicted that the forces of modernization and secularization would undermine religion as the world has known it—even cause its eventual disappearance. This theory was very compelling in the early decades of its life, both to those who would readily acquiesce to the demise of religion and to those who would mourn its loss. By the second half of the last century, however, the theory had acquired a very mixed record of evidence to support it. Some scholars attempted to retrench, arguing that though religion was not disappearing, it was fundamentally reorganizing itself in social life. Yet others began to doubt there could be any one process called ‘secularization’.