CHAP. I.—1. In the treatise which we wrote against the published epistle of Parmenianus to Tichonius, we promised that at some future time we would treat the question of baptism more thoroughly; and indeed, even if we had not made this promise, we are not unmindful that this is a debt fairly due from us to the prayers of our brethren. Wherefore in this treatise we have undertaken, with the help of God, not only to refute the objections which the Donatists have been wont to urge against us in this matter, but also to advance what God may enable us to say in respect of the authority of the blessed martyr Cyprian, which they endeavour to use as a prop, to prevent their perversity from falling before the attacks of truth. And this we propose to do, in order that all whose judgment is not blinded by party spirit may understand that, so far from Cyprian's authority being in their favour, it tends directly to their refutation and discomfiture.