Augustinian theodicy

The Augustinian theodicy, named for the 4th- and 5th-century theologian and philosopher Augustine of Hippo, is a type of Christian theodicy that developed in response to the evidential problem of evil. As such, it attempts to explain the probability of an omnipotent (all-powerful) and omnibenevolent (all-loving) God amid evidence of evil in the world. A number of variations of this kind of theodicy have been proposed throughout history; their similarities were first described by the 20th-century philosopher John Hick, who classified them as "Augustinian". They typically assert that God is perfectly (ideally) good, that he created the world out of nothing, and that evil is the result of humanity's original sin. The entry of evil into the world is generally explained as consequence of original sin and its continued presence due to humans' misuse of free will and concupiscence. God's goodness and benevolence, according to the Augustinian theodicy, remain perfect and without responsibility for evil or suffering.

Augustine of Hippo was the first to develop the theodicy. He rejected the idea that evil exists in itself, instead regarding it as a corruption of goodness, caused by humanity's abuse of free will. Augustine believed in the existence of a physical Hell as a punishment for sin, but argued that those who choose to accept the salvation of Jesus Christ will go to Heaven. In the 13th century, Thomas Aquinas – influenced by Augustine – proposed a similar theodicy based on the view that God is goodness and that there can be no evil in him. He believed that the existence of goodness allows evil to exist, through the fault of humans. Augustine also influenced John Calvin, who supported Augustine's view that evil is the result of free will and argued that sin corrupts humans, requiring God's grace to give moral guidance.

The theodicy was criticised by Augustine's contemporary Fortunatus, a Manichaean who contended that God must still be somehow implicated in evil, and 18th-century theologian Francesco Antonio Zaccaria criticised Augustine's concept of evil for not dealing with individual human suffering. Hick regards evil as necessary for the moral and spiritual development of humans, and process theologians have argued that God is not omnipotent and so cannot be responsible for any evil. The logic of Augustine's approach has been adapted by Alvin Plantinga, among others. Plantinga's adapted Augustinian theodicy, the free will defence – which he proposed in the 1980s – attempts to answer only the logical problem of evil. Such a defence (not a "theodicy" proper) does not demonstrate the existence of God, or the probable existence of God, but attempts to prove that the existence of God and the presence of evil (or privatio boni) in the world are not logically contradictory.