Chapters 3 and 4 are compact but rich summaries of the heart of Augustine’s metaphysics. He deals here with God, creation, the goodness of created things and the problem of evil. It’s surely one of Augustine’s great accomplishments as a thinker to clearly establish the basic outline of a sound Christian metaphysics.

While Augustine clearly remains influenced by neo-Platonism, he sharpens its metaphysics and brings it into closer conformity with biblical religion. The primary metaphysical distinction for Augustine isn’t between sensible and intelligible being or mind and body, but between created and uncreated being. God is uncreated being and everything else is created being. It’s not necessary, he says, for Christians to be expertly versed in philosophy or natural science, but it is necessary for them to grasp this elemental truth:

For the Christian, it is enough to believe that the cause of all created things, whether in heaven or on earth, whether visible or invisible, is nothing other than the goodness of the Creator, who is the one and the true God. Further, the Christian believes that nothing exists save God himself and what comes from him; and he believes that God is triune, i.e., the Father, and the Son begotten of the Father, and the Holy Spirit proceeding from the same Father, but one and the same Spirit of the Father and the Son.

This statement is an implicit rebuke to the various forms of gnosticism and manicheism floating around, which Augustine was all too familiar with, that held the material world to be the product of an evil force or lesser deity. But it also stakes out a position against a kind of neo-Platonic view that sees creation as “emanating” from God as a kind of effulgence rather than as the result of God’s gracious will.

Having established that creation is the product of a good God, he moves on to the affirmation of the goodness of creation itself:

By this Trinity, supremely and equally and immutably good, were all things created. But they were not created supremely, equally, nor immutably good. Still, each single created thing is good, and taken as a whole they are very good, because together they constitute a universe of admirable beauty.

This is a clear and beautiful summary of the Christian doctrine of creation. Creation is the gratuitous gift of a supremely good Creator and is itself a real, though lesser, good. It’s good because it is the handiwork of the Supreme Good.

But of course this leads ineluctably to the problem of evil. If creation is the good creation of a supremely good Creator, whence evil? “For the Omnipotent God, whom even the heathen acknowledge as the Supreme Power over all, would not allow any evil in his works, unless in his omnipotence and goodness, as the Supreme Good, he is able to bring forth good out of evil.”

Here we get Augustine’s justly famous doctrine of evil as privation. That is, considered in itself, evil is no-thing, but a lack or corruption in a being which is essentially good:

All of nature, therefore, is good, since the Creator of all nature is supremely good. But nature is not supremely and immutably good as is the Creator of it. Thus the good in created things can be diminished and augmented. For good to be diminished is evil; still, however much it is diminished, something must remain of its original nature as long as it exists at all. For no matter what kind or however insignificant a thing may be, the good which is its “nature” cannot be destroyed without the thing itself being destroyed.

This implies that, as good as creation is, it has an inherent vulnerability to evil. This is because created things are changeable, and therefore their goodness can be diminished. Only God is entirely impervious to evil. But that doesn’t change the fact that every being, no matter how corrupted it may become, remains good considered in itself as an entity. Augustine’s dictum that “every being, in so far as it is a being, is good” is a watchword for this metaphysic. “Nothing evil exists in itself, but only as an evil aspect of some actual entity. Therefore, there can be nothing evil except something good. Absurd as this sounds, nevertheless the logical connections of the argument compel us to it as inevitable.”

However, we still don’t know how, if creation is a real, though lesser, good, how evil arises in the first place. Augustine contends that only an evil will, itself the product of a good nature, whether human or angelic, can be the source of evil.

From a human nature there can spring forth either a good or an evil will. There was no other place from whence evil could have arisen in the first place except from the nature–good in itself–of an angel or a man. This is what our Lord himself most clearly shows in the passage about the trees and the fruits, for he said: “Make the tree good and the fruits will be good, or make the tree bad and its fruits will be bad.” This is warning enough that bad fruit cannot grow on a good tree nor good fruit on a bad one. Yet from that same earth to which he was referring, both sorts of trees can grow.

This leads to Augustine’s difficult doctrine of the Fall, which will come up in later chapters. For now, I just want to point out that what seems to be implied by his view of creation is that the evil will, at least in the beginning, is a kind of radical disruption of the good creation. And it’s something that seems radically undetermined by the nature of the being who posseses it, whether that’s a human being or an angel. Augustine has to hold this in order to be consistent with his view that the natures of created things are good in themselves. Otherwise, evil gets a kind of ontological foothold in creation.