This thinker claimed that Euclid's parallel postulate was self-evident but criticized another of Euclid's axioms for being grounded in empirical reasoning. In another book, this thinker thought up a "dream organ" that distorts sense-data and accounts for supernatural phenomena and hatefully railed against the adulation of a certain subclass with inferior reasoning skills and limited capacity for physical and mental work. This thinker wrote an "Essay on Ghost Seeing," classified objects as becoming, knowing, willing, and being in his doctoral dissertation, and revealed his misogyny in "On Women." In his most famous work, he drew on the Upanishads and criticized Kant's conception of the thing-in-itself as independent of our observations. For 
This thinker claimed that Euclid's parallel postulate was self-evident but criticized another of Euclid's axioms for being grounded in empirical reasoning. In another book, this thinker thought up a "dream organ" that distorts sense-data and accounts for supernatural phenomena and hatefully railed against the adulation of a certain subclass with inferior reasoning skills and limited capacity for physical and mental work. This thinker wrote an "Essay on Ghost Seeing," classified objects as becoming, knowing, willing, and being in his doctoral dissertation, and revealed his misogyny in "On Women." In his most famous work, he drew on the Upanishads and criticized Kant's conception of the thing-in-itself as independent of our observations. For 10 points, name this pessimistic philosopher, the author of Parerga and Parolipomena, The Fourfold Root, and The World as Will and Idea.
This thinker claimed that Euclid's parallel postulate was self-evident but criticized another of Euclid's axioms for being grounded in empirical reasoning.
Arthur Schopenhauer