Leibniz on the Best of All Possible Worlds and Theodicy

Leibniz's theodicy — his systematic attempt to reconcile the existence of evil and suffering with the existence of an omnipotent, omniscient, and perfectly good God — receives its fullest published treatment in the Essays on Theodicy on the Goodness of God, the Freedom of Man, and the Origin of Evil (Essais de Théodicée), published in French in 1710, the only one of Leibniz's major philosophical works published in full during his own lifetime; the term "theodicy" itself, from the Greek theos (god) and dike (justice), was coined by Leibniz for this work and has since become the standard general term for this branch of philosophy of religion. Leibniz's central and most quoted thesis, restated compactly in sections 53–55 of the Monadology, holds that among the infinitely many possible worlds that exist as ideas in the divine understanding — each internally consistent, since even divine power cannot instantiate a logical contradiction — God, guided by his perfect wisdom and goodness and constrained only by the principle of sufficient reason, necessarily selects and actualizes the single best of these possible worlds, meaning the one combining the greatest possible variety, richness, and complexity of phenomena with the greatest possible simplicity of the underlying laws that govern them.