One of the many problems that Saint Augustine faces in his Confessions is that of the nature of evil, and how its seeming existence might be reconciled with the omnipotence of God. During his association with the Manicheans, Augustine's conception of evil is that it is tangible, "a kind of material substance with its own foul and misshapen mass" (Confessions, 85). As he moves closer to his eventual conversion to Christianity, his view shifts; in contemplating the nature of good and what it means to exist, it becomes necessary for Augustine to abandon the notion that evil is something corporeal. In light of his newfound knowledge, the only explanation is that evil does not exist in the physical world -- for by his logic, this would present a contradiction in terms and is therefore impossible.

The doctrine of the Manicheans held it that both good and evil existed, in diametric opposition, and that the interplay between the two could be used to explain the human propensity toward sin; the action was necessary in order to maintain the balance between evil and good. Augustine himself was unable to conceive of anything that "existed which is not material"; in his view this was his first error of interpretation (83). This belief was all-encompassing and included even the divine, as he found that when it came to thinking of God he "knew of no way of doing so except as a physical mass" (83). Since pious respect for God and belief in his supreme goodness did not permit Augustine "to believe that the good God had created an evil nature", he postulated that both good and evil were infinite, but the former was somehow larger than the latter, as to think otherwise would be irreverent (83). Augustine also believed that God, in his infinite goodness, did not create any of the evil that was said to exist (83).

The first problem with this view of evil is in its relationship with God. For Augustine, the fact that good and evil are engaged in a struggle begs the question of what would happen if God, the good, "refused to fight against [the evil]" (112). If the powers of evil could injure God, then God is "open to violation and destruction" (112). This is contrary to God's omnipotent nature, and is therefore an unacceptable answer. Alternatively, if God could not be harmed by evil, there still remained the possibility that some subordinate part of God might become "mingled with hostile powers [...] and [...] corrupted by them" (113). The "hostile powers", of course, would not be of God's own creation, because everything that God created was good; but their negative influence would be such that the newly-corrupted part would require assistance "to deliver and purify it", returning it to its former state (113).

This element of God that is fallen from grace is the human soul, surmised the Manicheans, and the help that was needed to recover it came from the word of God (113). Following from this is a second and arguably more serious problem with the Manicheans' doctrine. Since the word of God "is of one and the same substance as the soul", it too is susceptible to corruption (113). But if the word of God, "free, pure, and intact" as it is, might be undermined by evil, then so too could God himself; it follows that "the entire story becomes false and execrable" in light of the contradiction (113). Augustine goes on to demolish this argument entirely by adding that if one were to take the opposite side and claim that God was, in fact, corruptible, "the very proposition is false" (113). His logic is irrefutable, and it quickly becomes evident that this element of the Manicheans' thoughts on the nature of good and evil is inherently flawed, and cannot possibly present an acceptable solution to the problem.

The Manicheans also "thought it more acceptable to say your substance suffers evil than that their own substance actively does evil" (113). This effectively waived their responsibility for their sins, giving it instead to keeping up the cosmic balance between good and evil. It was also unacceptable to Augustine, who proposed that "the free choice of the will is the reason why we do wrong and suffer [God's] just judgement" (113). This was a fairly radical departure from the Manichean perspective on the same issue; but by laying the blame for wrongdoing squarely on himself (and, by connection, on all of humankind), Augustine suggests a different origin for evil that might be easier to reconcile with the nature of God: within human beings, resulting from their free will.

Considering his own sins, Augustine says, "when I willed or did not will something, I was utterly certain that none other than myself was willing or not willing" -- that is, that any evil that came about as a result of his actions was his fault alone, as he was the one who made the decisions that preceded and resulted in the wrongdoing (114). He also experiences confusion about his motivations for committing sins in the first place; one of the turning points in the Confessions is when he realises, after stealing pears from a local orchard and discarding them uneaten, that the crime was utterly without motive, and could not possibly have eventuated in any good. This in turn raises another, more difficult question: why is it that a human being has "the power to will evil and to reject good?" (114) To address this question, Augustine turns to considering the nature of evil itself, rather than the act of sinning. Thus far evil has been considered as something corporeal and present in the physical world, but as considering it in this way created more problems than it solved, a new tactic is in order; for Augustine, it is examining the whole of nature to find the source of evil (115).

According to Genesis, it is an indisputable fact that God created the earth and everything on it; and since God is good, he "created good creatures" (115). Since all of his creations were good, then, perhaps it is the case that evil is in fact incorporeal; it "has no being" (115). The fear of evil, then, should have little rational basis; fearing something that by logic does not exist seems like efforts made in vain, but also implies that "fear itself is evil", resulting in the heart being unnecessarily "disturbed and tortured" (115-116). This explanation, where evil as such does not exist, seems closer to truth or at least more easily defensible than the Manicheans' view that evil is a tangible substance; but in order to be a truly satisfactory answer to the problem of evil, it needs to be proven.

In proving that evil cannot be corporeal, Augustine first asserts that "things which are liable to corruption are good" (124). This is true, because only good can be susceptible to corruption; for if something had no good in it, then there would be nothing to corrupt (124). Following this, then, it can be stated with certainty with relation to all things that "as long as they exist, they are good" (124). Logically, then, evil cannot possibly exist -- "for if it were a substance, it would be good" (125). Since the concept of evil, as antithetical to good, leaves no room for good contained within itself, it simply must not exist as something corporeal. Thus Augustine's earlier account of evil is refuted through logic.

In concluding his argument, Augustine returns to the immutable good of God, reiterating that all things are made to be good (125). In making this his final point, it becomes obvious that his original conception of evil was too flawed to stand up to intense scrutiny. To consider evil as an extant substance implies that God's omnipotence can be undermined and corrupted; Augustine's argument makes it clear that there is no way to reconcile the existence of corporeal evil with the existence of God, and that eliminating evil from consideration as a tangible thing is the only possible conclusion.

The Confessions of Saint Augustine, trans. Henry Chadwick. Oxford: Oxford University Press, 1991.
(All page references above come from this edition.)
with extra thanks to The Debutante.