St. Augustine wrote this work in the closing years of a life busied with three great controversies—Manichaeism, Donatism, Pelagianism, the last ending with the Contra Julianum and the Opus imperfectum contra Julianum. The year 411, which, for all practical purposes, saw the end of Donatism—a result largely due to Augustine—finds him beginning in earnest the conflict with Pelagianism, which was to occupy his time in sermons and a number of important writings for the rest of his days.

The Council of Carthage (411) condemned the teachings of Celestius, the disciple of Pelagius. The councils of Carthage were...

I should lie if I said that I despise your insults and evil words, Julian, which you breathed forth, burning with wrath, in your four books. For how could I despise them, when I see, in considering the testimony of my conscience, that I ought either to rejoice for myself or to grieve for you and for those whom you deceive? Who, indeed, despises the occasion of his rejoicing or grief? And we by no means despise that which in part causes gladness and in part sadness. Now the cause of my joy is the promise of the Lord, who...

Now I must undertake what I have put in the third section of my treatise, to overcome by the help of the Lord your machinations, Julian, by means of teachings of the bishops who have most gloriously dealt with the holy Scriptures. Not that I shall show that they believed about original sin according to the Catholic faith, for I have already done this in the first part of this work so that I might show to how many great men, holy and famous doctors of the Church, you impute the crime of Manichaeism, and, when you wish to defame...

Here are saintly men, many and great, learned in sacred letters, brilliant, highly honored and praised, for their remarkable government of the Church. If you will not now yield and accept their authority, you must surely assert that they erred, whether you choose to insult them as you insult me, or more gently show them a certain personal respect. Therefore, I am duty bound to answer you, Julian, my son, and, God willing, so to refute your books and your arguments that you will see, if you are able, that the thing of which you have tried to persuade others...

Let us now begin at the beginning of the second volume, and look at the rest of the arguments with which you try to refute my book. In accordance with our plan, we shall confine ourselves to real difficulties, avoiding superfluities, so as not to discourage the reader by too many words and prevent his paying adequate attention. In the foregoing book we said enough to make clear to those able to judge properly that the true and good God is the Creator of men; that marriage is a good which God instituted in the state and union of the...

Now that we have answered your first and second books, order demands we look at the contents of the third, and, with the Lord’s help, give your noxious efforts a wholesome answer. In accordance with our plan, we shall pass over irrelevant matters so that readers may learn our position with profit and without loss of time. Why need I say anything about the usual vain remarks at the beginning of your book, about how concerned you are in the cause of truth, and the lack of so-called prudent men whom you delight in pleasing? This is the cry of...

We have answered your third volume and now answer the fourth; with God’s help we shall give you charity as well as truth. Whoever has these two will never be guilty of folly or envy,¹ two vices discussed at length at the beginning of your volume. Error must yield to truth, envy to charity. When you speak of folly, saying: ‘It is the mother of all vices,’ you quote Scripture: ‘God loveth none but him that dwelleth with wisdom.’² Ask yourself seriously whether the childish vanity which man must necessarily pass through on his way from infancy can dwell with...