Tolkien’s Metaphysics of Evil, part 5
Prior to his conversion to Christianity, it was the dualistic account of evil that especially commended itself to Augustine, helping win him over to the sect of the Manichees. Eventually, however, Augustine came to reject the Manichaean portrayal of God as limited and capable of suffering persecution by the Kingdom of Darkness, and through his readings in the “books of the Platonists” he was exposed to the privation theory of evil taught by Plotinus. As the Bishop of Hippo writes in his City of God, “[t]here is no such entity in nature as ‘evil’; ‘evil’ is merely a name for the privation of good.” On account of his belief in the Christian doctrine of creation, moreover, according to which matter, too, is the deliberate creation and thus gift of an all-good and all-wise God, Augustine had additional reason to avoid the more dualistic tendencies of the Neoplatonic understanding of Evil. Thus, Augustine, for example, was inspired to reduce much more effectively than, for example, Plato did, the question of evil to the psychological question of moral evil or sin in the individual soul. In the process of solving Plato’s aporia, however, Augustine effectively introduced an altogether new mystery that would further preoccupy later thinkers such as Aquinas: if evil is nothing, it cannot have a cause, yet how can individual evil wills, which are themselves the cause of all evil, themselves be uncaused?
 As Scott MacDonald summarizes the perspective of the pre-converted Augustine, “[g]ranted that evil exists, Christianity appears incoherent: either evil comes from the supremely good God (which is absurd) or it does not (in which case God is not the creator of all that exists). By contrast, as Augustine understood it, Manichaenism had a ready answer to the first question. There are two ultimate sources of things, a good God and a hostile power independent of the good God. Evil derives not from the former but from the latter, and is a consequence of the evil power’s success in its cosmic struggle against the good God.” MacDonald, “The Divine Nature,” 74.
 Augustine, City of God 11.23, trans. Bettenson. Boethius similarly writes: “evil is nothing, since God, who can do all things, cannot do evil.” Boethius, Consolation of Philosophy, trans. Watts, 72.
 Elders suggests that it may very well have been the influence of the comparatively positive view of matter in Christian thought that induced later pagan Neoplatonists such as Proclus to modify their position on evil to a more consistent monism, maintaining that evil was a true privation and that matter, as a form of emanation from the One, was therefore not yet evil in itself. Elders, The Metaphysics of Being, 125-6.
 Steel, “Does Evil Have a Cause?” 256.
 Ibid. On Augustine versus Aquinas on the causality of evil, see also John Milbank, “Evil: Darkness and Silence,” 21.