2 Touching the very difficult question of will and grace, I have felt no need of treating it further in this letter, having given them another letter also when they were about to return in greater haste. I have written a book likewise for you, and if you, by the Lord's help, read it, and have a lively understanding of it, I think that no further dissension on this subject will arise among you. They take with them other documents besides, which, as we supposed, ought to be sent to you, in order that from these you may ascertain what means the Catholic Church has adopted for repelling, in God's mercy, the poison of the Pelagian heresy.
For the letters to Pope Innocent, Bishop of Rome, from the Council of the province of Carthage, and from the Council of Numidia, and one written with exceeding care by five bishops, and what he wrote back to these three; our letter also to Pope Zosimus about the African Council, and his answer addressed to all bishops throughout the world; and a brief constitution, which we drew up against the error itself at a later plenary Council of all Africa; and the above-mentioned book of mine, which I have just written for you,--all these we have both read over with them, while they were with us, and have now dispatched by their hands to you.
Source: Letters (New Advent)