Théodicée in the context of "Candide"

The phrase "the best of all possible worlds" (French: Le meilleur des mondes possibles; German: Die beste aller möglichen Welten) was coined by the German polymath and Enlightenment philosopher Gottfried Leibniz in his 1710 work Essais de Théodicée sur la bonté de Dieu, la liberté de l'homme et l'origine du mal (Essays of Theodicy on the Goodness of God, the Freedom of Man and the Origin of Evil), more commonly known simply as the Theodicy. The claim that the actual world is the best of all possible worlds is the central argument in Leibniz's theodicy, or his attempt to solve the problem of evil.

A theodicy (from Ancient Greek θεός theos, "god" and δίκη dikē, "justice"), meaning 'vindication of God', is an argument in the philosophy of religion that attempts to resolve the problem of evil, which arises when all power (omnipotence) and all goodness (omnibenevolence) are attributed to God simultaneously.

Unlike a defense, which tries only to demonstrate that God and evil can logically coexist, a theodicy additionally provides a framework in which God and evil's existence are considered plausible. The German philosopher and mathematician Gottfried Leibniz coined the term theodicy in his book Théodicée (1710), though numerous responses to the problem of evil had previously been offered.

New Essays on Human Understanding (French: Nouveaux essais sur l'entendement humain) is a chapter-by-chapter rebuttal by Gottfried Leibniz of John Locke's major work An Essay Concerning Human Understanding (1689). It is one of only two full-length works by Leibniz (the other being the Theodicy). It was finished in 1704, but Locke's death was the cause alleged by Leibniz to withhold its publication. The book was published in 1765, some 60 years following its completion. Leibniz had died in 1716, and never saw its published form.

Like many philosophical works of the time, it is written in dialogue form.