This introduction presents an overview of key concepts discussed in the subsequent chapters of the book. The book evaluates the purely critical sociology, and suggests that sociology can and should be constructive. It explores that sociology can be rescued from the clutches of contemporary sociologists, who think they are philosophers or warriors, and given a genuine job of enlightenment. The book proposes a calculation of the relations between theory and practice, between special kinds of thinking which have come to be called sociological theory and particular kinds of social practice which might call intervention. The history of a practical sociology becomes invisible for lack of use, while the continual rehearsal of a theoretical sociology leads up to only one kind of performance, theory and one kind of action, theoreticism. Motivating and moralizing are important parts of the theoretical enterprise and sociology needs to exploit the values of compassion, activism, and the desire to help rather than cynicism, academicism and quietism.