ABSTRACT
The Introduction to the book argues for the necessity of basic categories for the social sciences in general and for sociology in particular, which allows to define their subject matter analytically. These categories need to be open to empirical studies, yet they also need to be consistently and coherently set in the frame of the problems by which sociality is defined as a scientific object. In order to do so, the introduction proposes a distinction between social theory which includes the basic set of categories for the social sciences, sociological theory as the theory of the empirical order and variety of societies, and sociological diagnosis as the study of social changes in contemporary societies. This distinction constitutes also the basic structure of the book, as indicated by the Roman numerals of the chapters.
