The philosophy of religion as presented by Hermann Cohen and Paul Natorp, the founders and main representatives of the Marburg School of Neo-Kantianism, is an important and at the same time controversial part of their philosophical systems. The discussion around the problems of religion began within the Marburg School and still continues among those who study that School. The reason for this is that “fitting” philosophical thinking about the phenomenon of religion into the classical triad of any system of philosophy, (...) i. e. effectively formulating that phenomenon in logical concepts, ethical postulates and aesthetic principles touched the very foundations of that system. Drawing mainly on the rough notes and correspondence of Cohen and Natorp I argue that, in spite of internal and quite important differences over the problems of religion and its place in philosophical constructions, Cohen and Natorp, first, retained their commitment to critical idealism and remained loyal to their philosophical school to the end and, second, followed the principle of mutual respect, preserving their professional and human sympathy for each other. Besides, I substantiate my assertion that Marburg Neo-Kantians had different concepts of the special place of religion in the system of philosophy. The specific nature of this difference warrants the discussion not only of the boundary of reason and rationality but adds new dimensions to that boundary, filling it with content and thus broadening the very sphere of critical idealism. In the course of the discussion of the problems of religion, Paul Natorp and Hermann Cohen stake a claim to projects for the serious transformation of philosophy which they tried to implement in their later works. (shrink)