Fourfold Root of the Principle of Sufficient Reason
analyses of causation and related concepts . . . rival and
probably surpass in their depth and brilliance the more
celebrated discussions of David Hume. Where Hume grossly
oversimplified these problems and left them riddled with
paradoxes, Schopenhauer disentangled them and shed light on what
had seemed hopelessly dark."
—Richard Taylor, University of Rochester