5 Wherefore the holy Cyprian, whose dignity is only increased by his humility, who so loved the pattern set by Peter as to use the words, "Giving us thereby a pattern of concord and patience, that we should not pertinaciously love our own opinions, but should rather account as our own any true and rightful suggestions of our brethren and colleagues, for the common health and good," — he, I say, abundantly shows that he was most willing to correct his own opinion, if any one should prove to him that it is as certain that the baptism of Christ can be given by those who have strayed from the fold, as that it could not be lost when they strayed; on which subject we have already said much.
Nor should we ourselves venture to assert anything of the kind, were we not supported by the unanimous authority of the whole Church, to which he himself would unquestionably have yielded, if at that time the truth of this question had been placed beyond dispute by the investigation and decree of a plenary Council. For if he quotes Peter as an example for his allowing himself quietly and peacefully to be corrected by one junior colleague, how much more readily would he himself, with the Council of his province, have yielded to the authority of the whole world, when the truth had been thus brought to light?
For, indeed, so holy and peaceful a soul would have been most ready to assent to the arguments of any single person who could prove to him the truth; and perhaps he even did so, though we have no knowledge of the fact. For it was neither possible that all the proceedings which took place between the bishops at that time should have been committed to writing, nor are we acquainted with all that was so committed. For how could a matter which was involved in such mists of disputation even have been brought to the full illumination and authoritative decision of a plenary Council, had it not first been known to be discussed for some considerable time in the various districts of the world, with many discussions and comparisons of the views of the bishop on every side?
But this is one effect of the soundness of peace, that when any doubtful points are long under investigation, and when, on account of the difficulty of arriving at the truth, they produce difference of opinion in the course of brotherly disputation, till men at last arrive at the unalloyed truth; yet the bond of unity remains, lest in the part that is cut away there should be found the incurable wound of deadly error.
Source: On Baptism, Against the Donatists (New Advent)