This volume collects 12 essays by various contributors on the subject of the importance and influence of Schopenhauer s doctoral dissertation (On the Fourfold Root of the Principle of Sufficient Reason) for both Schopenhauer s more well-known philosophy and the ongoing discussion of the subject of the principle of sufficient reason. The contributions deal with the historical context of Schopenhauer s reflections, their relationship to (transcendental) idealism, the insights they hold for Schopenhauer s views of consciousness and sensation, and how they illuminate Schopenhauer s theory of...