Nicene and Post-Nicene Fathers, Vol. V:
A Treatise Against Two Letters of the...: Chapter 26

Chapter 26 [X.]—The Pelagians Still Strive After a Hiding-Place, by Introducing the Needless Question of the Origin of the Soul.

The Pelagians, indeed, add to the clouds which envelop their lurking-places the unnecessary question concerning the origin of the soul, for the purpose of erecting a hiding-place by disturbing manifest things by the obscurity of other matters. For they say “that we guard the continuous propagation of souls with the continuous propagation of sin.” And where and when they have read this, either in the addresses or in the writings of those who maintain the catholic faith against this, I do not know; because, although I find something written by catholics on the subject, yet the defence of the truth had not yet been undertaken against those men, neither was there any anxiety to answer them. But this I say, that according to the Holy Scriptures original sin is so manifest, and that this is put away in infants by the laver of regeneration is confirmed by such antiquity and authority of the catholic faith, notorious by such a clear concurrent testimony of the Church, that what is argued by the inquiry or affirmation of anybody concerning the origin of the soul, if it is contrary to this, cannot be true. Wherefore, whoever builds up, either concerning the soul or any other obscure matter, any edifice whence he may destroy this, which is true, best founded, and best known, whether he is a son or an enemy of the Church, must either be corrected or avoided. But let this be the end of this Book, that the things which follow may have another beginning.