Nicene and Post-Nicene Fathers, Vol. IV:
Writings in Connection with the Donatist Controversy.: Chapter 15

Chapter 15.—17.  Read now the most profuse revilings which he has poured forth whilst puffed up with indignation against me, and see whether he has given me any answer, when I ask what means are to be found for cleansing one who receives baptism when the conscience of the giver is polluted, without the knowledge of him who receives the sacrament at his hands.  I beg of you to search minutely, to examine every page, to reckon every line, to ponder every word, to sift the meaning of each syllable, and tell me, if you can discover it, where he has made answer to the question, What means are to be found for cleansing the conscience of the recipient who is unaware that the conscience of the giver is polluted?

18.  For how did it bear upon the point that he added a phrase which he said was suppressed by me, maintaining that he had written in the following terms:  "The conscience of him who gives in holiness is what we look for to cleanse the conscience of the recipient?"  For to prove to you that it was not suppressed by me, its addition in no way hinders my inquiry, or makes up the deficiency which was found in him.  For in the face of those very words I ask again, and I beg of you to see whether he has given any answer, If "the conscience of him who gives in holiness is what we look for to cleanse the conscience of the recipient," what means are to be found for cleansing the conscience of the recipient when the conscience of the giver is stained with guilt, without the knowledge of him who is to receive the sacrament at his hands?  I insist upon an answer being given to this.  Do not allow that any one should be prejudiced by revilings irrelevant to the matter in hand.  If the conscience of him who gives in holiness is what we look for,—observe that I do not say "the conscience of him who gives," but that I added the words, "of him who gives in holiness,"—if the conscience, then, of him who gives in holiness is what we look for, what means are to be found for cleansing one who receives baptism when the conscience of the giver is polluted, without the knowledge of him who is to receive the sacrament at his hands?