Why Is There Anything At All

This is perhaps the most famous question in Western metaphysics, appearing in Gottfried Wilhelm Leibniz's essay Principles of Nature and Grace, Based on Reason (1714). Leibniz used it to motivate his principle of sufficient reason: since pure nothingness would have been simpler and required no explanation, the existence of something demands a reason — which he located in God as a necessary being whose essence entails existence. The question was later taken up by Martin Heidegger, who called it "the fundamental question of metaphysics."