A Treatise on the predestination of the saints,
by aurelius augustin, bishop of hippo;
The First Book, 3413
addressed to prosper and hilary. 
a.d. 428 or 429
Wherein the truth of predestination and grace is defended against the semi-Pelagians,—those people to wit, who by no means withdraw altogether from the Pelagian heresy, in that they contend that the beginning of salvation and of faith is of ourselves; so that in virtue, as it were, of this precedent merit, the other good gifts of God are attained. Augustin shows that not only the increase, but the very beginning also of faith is in Gods gift. On this matter he does not disavow that he once thought differently, and that in some small works, written before his episcopate, he was in error, as in that exposition, which they object to him, of propositions from the epistle to the Romans. But he points out that he was subsequently convinced chiefly by this testimony, “but what hast thou that thou hast not received?” which he proves is to be taken as a testimony concerning faith itself also. He says that faith is to be counted among other works, which the apostle denies to anticipate Gods grace when He says, “not of works.” He declares that the hardness of the heart is taken away by grace, and that all come to Christ who are taught to come by the Father; but that those whom He teaches, He teaches in mercy, while those whom He teaches not, in judgment He teaches not. That the passage from his hundred and second epistle, Question 2, “concerning the time of the Christian religion” which is alleged by the semi-Pelagians, may rightly be explained without detriment to the doctrine of grace and predestination. He teaches what is the difference between grace and predestination. Further, he says that God in his predestination foreknew what he had purposed to do. He marvels greatly that the adversaries of predestination, who are said to be unwilling to be dependent on the uncertainty of Gods will, prefer rather to trust themselves to their own weakness than to p. 498 the strength of Gods promise. He clearly points out that they abuse this authority, “If thou believest, thou shalt be saved.” That the truth of grace and perseverance shines forth in the case of infants that are saved, who are distinguished by no merits of their own from others who perish. For that there is no difference between them arising from the foreknowledge of merits which they would have had if they had lived longer. That testimony is wrongfully rejected by the adversaries as being uncanonical, which he adduced for the purpose of this discussion, “he was taken away lest wickedness,” etc. That the most illustrious instance of predestination and grace is the Saviour Himself, in whom a man obtained the privilege of being the Saviour and the Only-begotten Son of God, through being assumed into oneness of person by the Word co-eternal with the Father, on account of no precedent merits, either of works or of faith. That the predestinated are called by some certain calling peculiar to the elect, and that they have been elected before the foundation of the world; not because they were foreknown as men who would believe and would be holy, but in order that by means of that very election of grace they might be such, etc.
This Treatise is the first portion of a work, of which the following, On the Gift of Perseverance, is the second.