 The late antique (Plotinus, Proclus, Augustine, Boethius), medieval (Anselm, Ibn Sina, Aquinas), and early modern (Descartes, Leibniz, Bayle, Kant) eras contain sophisticated traditions of reflection on questions about evil—about its being or non-being, its intrinsic features and natural manifestations, and its origins in nature, will, or supernature. Over the course of that centuries-long discussion, two main distinctions emerged.