Fragments of the Letter to Philemon

I indeed was giving my attention to reading the books of heretics and learning their traditions, for a time defiling my mind with their accursed opinions, yet deriving this benefit from them, that I refuted them in my own estimation and detested them far more greatly. And when a certain brother from the order of presbyters was dissuading me, and feared lest I be plunged into the same mire of wickedness; for he said, and truly as I myself felt, that my mind would be contaminated: I was confirmed by a vision divinely sent, and a word was addressed to me which plainly commanded me, saying: Read all things whatsoever shall come into your hands; for you are capable of examining and proving each thing: and from this there arose for you first the cause and occasion of believing. This vision I received as one consonant with the apostolic voice, which thus addresses those endowed with greater virtue: Be ye approved money-changers (I Thes. V, 21).

This rule and norm I received from our blessed pope Heraclas. For those who came from heresies, even if they had fallen away from the Church, or rather had not even fallen away, but while they were seen to frequent the assemblies of the faithful, had been accused of going to hear teachers of perverse doctrine, he cast out from the Church, and after many prayers did not admit them until they had publicly and openly recounted all that they had heard from the adversaries. Then at last he admitted them to the assemblies of the faithful, by no means requiring them to receive baptism a second time. For they had already previously received the Holy Spirit from him.

I have moreover learned that this custom was not introduced for the first time now among the Africans alone, but that even much earlier in the times of bishops of former days it had pleased the most populous churches, and the synods of brethren held at Iconium and Synnada, as well as very many others. To overturn their decisions and cast them into quarrels and contentions I would not wish. For it is said: Thou shalt not remove the landmarks of thy neighbour, which thy fathers have set.