The paper analyzes Max Weber’s concepts of rationality and rationalization as components of modernization processes in modern society. The author reconstructs Weber’s interpretation of “spiritual factors” of social development, which emerge in the ethos of Protestantism. The research demonstrates how Weber’s study of capitalism in terms of rationality corresponds with concepts of other classics of German sociology, such as Ferdinand Tönnies, Werner Sombart, Georg Simmel and others. The article emphasizes the relevance of Weber’s sociology for XX— XXI centuries and how (...) its basic concepts and methodological approaches have been further developed by scholars, including Ukrainian ones. Weber’s concept of rationality is applicable not only to the mental-epistemological sphere, it also acquires a social meaning. This approach has gained recognition in phenomenological sociology, theory of social systems, communicative theory and more. In addition to the formal rationality of the economy, modern social sciences use such concepts as social, aesthetic, ethical, environmental, and practical rationality. Weber’s “diagnosis of the age” is still a component of the “diagnosis” of modern society. The gap between values and interests remains an integral feature of the “risks and threats society” in the XXI century. This situation is especially evident in international relations, when “real politics” (Realpolitik), based on interests, becomes insensitive to “value postulates”. The author also discovers ways of value (moral and ethical) reclamation of modern society, particularly in the concepts of “ethical economy”, universalist ethics of discourse, global ethos and more. Keywords: purposive rationality, rationality (formal, material, communicative, systemic), value, ethos. (shrink)