A purely rational belief is ... the signpost or compass by which the specu­la­tive thinker can orient himself in his rational excursions in the field of super­sensuous objects. But to the man of ordinary but (morally) sound reason, it can show the way for both the theore­ti­cal and the practical standpoint, in a manner entirely suitable to the end to which he is destined. This rational belief must also be made the basis of every other be­lief—indeed of every revela­tion. [Kt20:142]