This fifth and final chapter presents an original translation of the methodologically most important chapter of Weber's seminal work for the social sciences, Economy and Society. In this chapter, Weber integrates the contributions of Menger and Simmel, but avoids the formalist inspiration of the economist's methodological expositions on the one hand, and the philosopher's emphasis on understanding the mental states of historical actors on the other. Weber highlights the intrinsic connection between the decomposition of social wholes into basic units, implied by the individualist method, and the understanding approach. In this way, he explains the proximity of the methods of the natural and social sciences and the specificity of the relationship of social scientists to their objects. The latter can mentally grasp what motivates people's actions, whereas natural scientists essentially formulate theoretical hypotheses on the basis of empirical data. Weber thus conceptualizes the specificity of causality in the social sciences by referring it to the reasons that subjectively drive the actions of social actors.