Kant

(1724-1804) German philosopher; tried to unite rationalism and empiricism ; wrote 1. Religion Within the Bounds of Reason, 2. Critique of Pure Reason, 3. Critique of Practical Reason, and 4. Critique of Judgment. Regarding his theory of reality: reality as "thing-in-itself" (Ding an sich) or as noumena is unknowable. Noumena present themselves to minds as phenomena which are knowable. Phenomena are the joint product of mind and sense data. Phenomena are possible only because mind is capable of ordering them in space and time. Mind knows only what it orders in space and time according to the principle of causality as phenomena or experience. Mind cannot know what it is as "thing-in-itself." Mind knows only phenomena .