The history of the secularization of modern culture has yet to be written, and the reasons for this are easy enough to understand. For on the one hand, the mind of the secularized majority has been so deeply affected by the process of secularization that it cannot view that process in an objective historical manner, while on the other, the religious minority has been forced into an attitude of negative opposition which is no less unfavorable to dispassionate study. Nevertheless, it is emphatically a problem which requires an historical approach. The process of secularization was a historical movement no less than the Reformation, a minority movement which was gradually transmitted to wider circles until it eventually won the key positions of social and intellectual influence through which it dominated European society. This movement, which was already known as the Enlightenment in the eighteenth century, and the accompanying ideology, which later acquired the name of Liberalism, have long been studied by historians chiefly in Germany and France, though in a somewhat piecemeal fashion; but their work has not hitherto been fully assimilated by educated opinion in England and America. Here the tendency has been to concentrate attention on political and economic change, and above all on the American and French revolutions. But we have not paid enough attention to the intellectual revolution that had already taken place before there was any question of a political one. Yet it is this intellectual revolution that is responsible for the secularization of Western culture. This intellectual movement, like most of the movements that have changed the world, was religious in origin, although it was anti-religious in its results. It owed its dynamism to the resistance of a religious minority and its diffusion to the illjudged and unjust, though sincere, action of religious orthodoxy. It is indeed, the supreme example in history of the way in which religious persecution and repression defeats its own object and serves the cause it is attempting to destroy.