This author of Parerga and Paralipomena wrote On the Fourfold Root of the Principle of Sufficient Reason, and another work argues that art tries to represent the Platonic ideal of an object and that works expands Kant's "Ding an Sich" to the whole universe.
One of his works claims that twelve categories of human understanding posited in the Critique of Judgment are reducible to causality.  His last work, a set of "stray yet systematically arranged thoughts on a variety of subjects," includes sections "On Din and Noise" and "Additional Remarks on the Doctrine of the Suffering of the World."  This author of Parerga and Paralipomena wrote On the Fourfold Root of the Principle of Sufficient Reason, and another work argues that art tries to represent the Platonic ideal of an object and that works expands Kant's "Ding an Sich" to the whole universe. For 10 points, supposed pessimist, the author of The World as Will and Idea.
One of his works claims that twelve categories of human understanding posited in the Critique of Judgment are reducible to causality.  
Arthur Schopenhauer