Monism

=====Rejection of radical dualism=====
In ''[[De libero arbitrio (Augustine)|On Free Choice of the Will]]'', [[Augustine of Hippo|Augustine]] argued, in the context of [[the problem of evil]], that evil is not the opposite of good, but rather merely the absence of good, something that does not have existence in itself. Likewise, [[C. S. Lewis]] described evil as a "parasite" in ''[[Mere Christianity]]'', as he viewed evil as something that cannot exist without good to provide it with existence. Lewis went on to argue against dualism from the basis of [[moral absolutism]], and rejected the dualistic notion that God and [[Satan]] are opposites, arguing instead that God has no equal, hence no opposite. Lewis rather viewed Satan as the opposite of [[Michael (archangel)|Michael the archangel]]. Due to this, Lewis instead argued for a more limited type of dualism.<ref>Lewis, C. S. 1970, "God and Evil" in ''God in the Dock: Essays in Theology and Ethics'', ed. W. Hooper, Grand Rapids, [[Michigan | MI]]: Eerdsman, pp. 21–24</ref> Other theologians, such as [[Greg Boyd (theologian) |Greg Boyd]], have argued in more depth that the Biblical authors held a "limited dualism", meaning that God and Satan do engage in real battle, but only due to free will given by God, for the duration that God allows.<ref>Boyd, Gregory. A 1971, ''God at War'', Downers Grove, [[Illinois | IL]]: InterVarsity Press, p. 185</ref>