Abstract

THE MAIN THESIS OF THIS STUDY may be summarized as follows: In Schopenhauer's earliest work, The Fourfold Root of the Principle of Sufficient Reason, two different lines of philosophical thought can be identified, each arising from a different source. The first of these is the a priori Kantianism and idealism heavily emphasizing the function of the a priori principle of causality, and the forms of time and space. This line comes from Schopenhauer's study of Kantianism. The second line of thought consists of an implicitly realistic analysis of perception which seems to arise from Schopenhauer's personal reflection on perceptual experience. This experiential analysis seems to be partially due to his medical studies, as his use of medical rather than philosophical authorities indicates. This realistically oriented element can be extricated from the totality of Schopenhauer's philosophy with the result that it can furnish new insights valuable for the understanding and confirmation of philosophical direct realism.