REASON (More)

[A310/B367] The idea seems to be that knowledge requires all three faculties (and sensibility as well): by providing intuitions and concepts, sensibility and understanding provide "the material required" for experience, judgment unifies this material in a certain way, and then reason provides further unity, "an a priori unity by means of concepts" which is associated with the act of inference. This additional unity is peculiar, because Kant's analysis of empirical knowledge and sensible experience seems complete after
the act of judgment. Reason's "a priori unity" which further unifies the unity provided by judgment seems to be some kind of unity of practical reason, some sort of teleological or regulative unity of "purpose in nature", required by man's need to go beyond the empirical sphere and grasp the "unconditioned".