 Schopenhauer’s claim that the subject-object distinction is the most general condition for human knowledge has its theoretical source in Kant’s Critique of Pure Reason, for Kant similarly grounded his own theory of knowledge upon a highly-abstracted, formalized, and universalized subject-object distinction. Kant characterized the subjective pole of the distinction as the contentless transcendental unity of self-consciousness and the objective pole as the contentless transcendental object that corresponds to the concept of an object in general (CPR, A 109). The general root of the principle of sufficient reason, as Schopenhauer characterizes it, is at the root of Kant’s epistemology as well. 