[strlen]

Popper was a fan of Schopenhauer - while he rejected Schopenhauer's metaphysics of the Will, he positively quotes Schopenhauer in Open Society and its Enemies (especially in regards to Hegel). There's also evidence that Popper's interpretation of Kant is through Schopenhauer: the Principle of Sufficient Reason, the first book of World as Will and Representation, and the appendix to the first volume also function as a good emendation of and commentary upon on Kant's Critique of Pure Reason and Prolegomena.