What follows is an account of an issue that bears centrally on the relationship of sociology to religion and of sociology to theology. It is a retrospective account of a personal encounter with this particular issue. That issue is secularization. Sociology itself emerged as part of the process of secularization because it represented the autonomous study of Man in Society. But the circumstances of its emergence meant that it gave an absolutely central place to the problem of secularization and encased that problem in an ideological frame, in part derived from the philosophy of history. Sociology itself, as John Milbank has argued, has a deep structure of ideology embedded in its very foundations.1 However, unlike Milbank I do not believe that its whole discourse is self-contained beyond correction. Ideology, once observed, can be countered. The guiding paradigms of sociology, such as secularization, can be made analytically coherent and descriptively accurate. However, that means reducing ‘grand theory’ to tendencies which are to be observed in certain definable circumstances and not in others and, moreover, those circumstances need to be seen as varying greatly according to historical context. In what follows, I present the viable core of secularization as the sub-theory of social differentiation. Serious doubts can be raised about the sub-theory of rationalization, and an important work of José Casanova2 criticizes the sub-theory of privatization (which happens also to have implications for theological reflections on society).