Nicene and Post-Nicene Fathers, Vol. IV:
Writings in Connection with the Donatist Controversy.: Chapter 45

Chapter 45.—54.  But that neither he nor any one of you might say that, when any one of concealed bad character is the baptizer, then he whom he baptizes is not his fruit, but the fruit of Christ, I went on immediately to point out what a foolish error is consequent also on that opinion; and I repeated, though in other words, what I had said shortly before:  If, when the quality of the tree is concealed, but evil, any one who may have been baptized by it is born, not of it but of Christ, then they are justified with greater holiness who are baptized by wicked men, whose wickedness is concealed, than they who are baptized by men that are genuinely and manifestly good. 2416   Petilianus then, being hemmed in by these embarrassing straits, said nothing about the earlier part on which these remarks depended, and in his answer so quoted his absurd consequence of his error as though I had stated it as my own opinion, whereas it was really stated in order that he might perceive the amount of evil consequent on his opinion, and so be forced to alter it.  Imposing, therefore, this deceit on those who hear and read his words, and never for a moment supposing that what we have written could be read, he begins a vehement and petulant invective against me, as though I had thought that all who are baptized ought to wish that they might have as their baptizers men who are faithless, without knowing this themselves, since, however good the men might be whom they had to baptize them, Christ is incomparably better, who will then be the head of the person baptized, if the faithless baptizer conceal his true character.  As though, too, I had thought that those were justified with greater holiness who are baptized by evil men, whose character is concealed, than those who are baptized by men that are genuinely and manifestly good; when this marvellous piece of madness was only mentioned by me as following necessarily on the opinion of those who think with Petilianus, that a man, when baptized, bears the same relation to his baptizer as fruit does to the tree from which it springs,—good fruit springing from a good tree, evil fruit from an evil tree,—seeing that p. 619 they, when they are bidden by me to answer whose fruit they think a man that is baptized to be when he is baptized by one of secretly bad character, since they do not venture to rebaptize him, are compelled to answer, that then he is not the fruit of that man of secretly bad character, but that he is the fruit of Christ.  And so they are followed by a consequence contrary to their inclination, which none but a madman would entertain,—that if a man is the fruit of his baptizer when he is baptized by one that is genuinely and manifestly good, but when he is baptized by one of secretly bad character, he is then not his fruit, but the fruit of Christ,—it cannot but follow that they are justified with greater holiness who are baptized by men of secretly bad character, than those who are baptized by men who are genuinely and manifestly good.

Footnotes

See Book I. cc. 7, 8, 8, 9.