Since its first publication in 1965, this study of the theories that interpret modern society as a result of a process of secularization has become a standard work in the history of concepts. It analyzes the changing functions that secularization has fulfilled as a program and slogan, as a descriptive category of social processes, or as a civilization-critical interpretative scheme for the emergence of modern society up to the present day. This excellent and fascinating study illustrates in a compelling way the idea of a philosophical history of concepts that Lübbe presents in the introduction. He traces the origin of the initially value-neutral word, which refers to the intentional and self-serving relinquishment of goods by the Church from its sphere of influence. He then follows the transformations of meaning that occur within this context.