This book examines the multiple relationships between the concepts of the rational and the irrational present in Max Weber's thought. Although the first pole of this opposition has been highlighted as the central theme of his work, there is still considerable ambiguity and imprecision about its meaning and scope. The second concept, meanwhile, remains largely unexplored. To help clarify them, this paper systematizes the Weberian categories of rationality and irrationality, defining their meaning and elaborating a typology of each; and also those of rationalization and charisma understood as historical forces, describing their typical phases of development and analyzing the limits of rationalism in modernity.

The reconstruction highlights the pervasive tensions between the two poles, contributing to the understanding of Weber's idea of rationality – key to understanding his vision of modern bureaucracy, science and capitalism – and revealing that the irrational has a much more important role in his work than is usually recognized.