In the wake of the renewed interest in the philosophy of Immanuel Kant, the neo-Kantian theories of Heinrich Rickert (1863-1936) are increasingly drawing attention. This monograph is an attempt to rescue Rickert from an undeserved oblivion by an analysis of his systematic philosophy of values. The author discusses Rickert's epistemology and ontology which lay the foundation for a methodology of the Natural Sciences and the Humanities. In Rickert's view these types of science are not in opposition to each other but operate on a continuum between two extremes: a 'generalizing' (natural-scientific) and an 'individualizing' (cultural-scientific) approach to reality. The social sciences in particular operate on this continuum in a flexible manner, sometimes close to the natural-scientific pole as in the case of experimental psychology or econometrics, sometimes close to the cultural-scientific approach, as in the case of cultural sociology or cultural history. Thus there is in Rickert's logic of science no room for any methodological quarrel.