Theodicy

Gottfried Wilhelm Leibniz's Theodicy (1710) is the founding modern philosophical treatment of the problem of evil. Written in long-running argument with Pierre Bayle, it sustains three essays: on the conformity of faith with reason, on the goodness of God and the freedom of man, and on the origin of evil. The book is the source of the famous (and famously caricatured) doctrine that this is the best of all possible worlds.