Abstract

After a remark on the logic of meaning variance, part I explicates the chapter’s heading concepts. As a human faculty, reason is distinguished from rationality, being a quality of human products. The systematical role of reason is historically described from classical antiquity until modern times. Globality of reason in the sense of its being universal is emphasized. Subjectively in distinction from objectively rational human actions are explained. Part II shows, how functions and tasks of reason as well as the moments of rationality underlie the global turn. Especially the concepts of practical reason, e.g., justice, change under empirically altering conditions. The goal of reason’s activity is to design globally valid theories. As a consequence hereof, part III claims to qualify received concepts and theses of reason by their local conditions.