Of the Universal Way of the Soul's Deliverance, Which Porphyry Did Not Find Because He Did Not Rightly Seek It, and Which the Grace of Christ Has Alone Thrown Open
And therefore, in these ten books, though not meeting, I dare say, the expectation of some, yet I have, as the true God and Lord has vouchsafed to aid me, satisfied the desire of certain persons, by refuting the objections of the ungodly, who prefer their own gods to the Founder of the holy city, about which we undertook to speak. Of these ten books, the first five were directed against those who think we should worship the gods for the sake of the blessings of this life, and the second five against those who think we should worship them for the sake of the life which is to be after death. And now, in fulfillment of the promise I made in the first book, I shall go on to say, as God shall aid me, what I think needs to be said regarding the origin, history, and deserved ends of the two cities, which, as already remarked, are in this world commingled and implicated with one another.
Source: City of God (New Advent)