"But that no one might have occasion to say, that though I had refuted the tenets of other men, I had omitted to establish my own, I devote to this object the second part of this work, which comprises twelve books, although I have not scrupled, as occasion offered, either to advance my own opinions in the first ten books, or to demolish the arguments of my opponents in the last twelve. Of these twelve books, the first four contain an account of the origin of these two cities--the city of God, and the city of the world. The second four treat of their history or progress; the third and last four, of their deserved destinies. And so, though all these twenty-two books refer to both cities, yet I have named them after the better city, and called them The City of God." Such is the account given by Augustine himself[2] of the occasion and plan of this his greatest work. But in addition to this explicit information, we learn from the correspondence[3] of Augustine, that it was due to the importunity of his friend Marcellinus that this defence of Christianity extended beyond the limits of a few letters. Shortly before the fall of Rome, Marcellinus had been sent to Africa by the Emperor Honorius to arrange a settlement of the differences between the Donatists and the Catholics. This brought him into contact not only with Augustine, but with Volusian, the proconsul of Africa, and a man of rare intelligence and candour. Finding that Volusian, though as yet a pagan, took an interest in the Christian religion, Marcellinus set his heart on converting him to the true faith. The details of the subsequent significant intercourse between the learned and courtly bishop and the two imperial statesmen, are unfortunately almost entirely lost to us; but the impression conveyed by the extant correspondence is, that Marcellinus was the means of bringing his two friends into communication with one another. The first overture was on Augustine's part, in the shape of a simple and manly request that Volusian would carefully peruse the Scriptures, accompanied by a frank offer to do his best to solve any difficulties that might arise in such a course of inquiry. Volusian accordingly enters into correspondence with Augustine; and in order to illustrate the kind of difficulties experienced by men in his position, he gives some graphic notes of a conversation in which he had recently taken part at a gathering of some of his friends. The difficulty to which most weight is attached in this letter, is the apparent impossibility of believing in the Incarnation. But a letter which Marcellinus immediately despatched to Augustine, urging him to reply to Volusian at large, brought the intelligence that the difficulties and objections to Christianity were thus limited merely out of a courteous regard to the preciousness of the bishop's time, and the vast number of his engagements. This letter, in short, brought out the important fact, that a removal of speculative doubts