Nicene and Post-Nicene Fathers, Ser. II, Vol. XIV:
The Canons of the Council in Trullo; Often Called The Quinisext Council.: Canon XCV

Canon XCV.

Those who from the heretics come over to orthodoxy, and to the number of those who should be saved, we receive according to the following order and custom.  Arians, Macedonians, Novatians, who call themselves Cathari, Aristeri, and Testareskaidecatitæ, or Tetraditæ, and Apollinarians, we receive on their presentation of certificates and on their anathematizing every heresy which does not hold as does the holy Apostolic Church of God:  then first of all we anoint them with the holy chrism on their foreheads, eyes, nostrils, mouth and ears; and as we seal them we say—“The seal of the gift of the Holy Ghost.”

But concerning the Paulianists it has been determined by the Catholic Church that they shall by all means be rebaptized.  The Eunomeans also, who baptize with one immersion; and the Montanists, who here are called Phrygians; and the Sabellians, who consider the Son to be the same as the Father, and are guilty in certain other grave matters, and all the other heresies—for there are many heretics here, especially those who come from the region of the Galatians—all of their number who are desirous of coming to the Orthodox faith, we receive as Gentiles.  And on the first day we make them Christians, on the second Catechumens, then on the third day we exorcise them, at the same time also breathing thrice upon their faces and ears; and thus we initiate them, and we make them spend time in church and hear the Scriptures; and then we baptize them.

And the Manichæans, and Valentinians and Marcionites and all of similar heresies must give certificates and anathematize each his own heresy, and also Nestorius, Eutyches, Dioscorus, Severus, and the other chiefs of such heresies, and those who think with them, and all the aforesaid heresies; and so they become partakers of the holy Communion.

Notes.

Ancient Epitome of Canon XCV.

Thus we admit those converted from the heretics.  We anoint with the holy chrism, upon the brow, eyes, nostrils, mouth, and ears, Arians, Macedonians, Novatians (who are called Cathari), Aristerians (who are called Quartadecimans or Tetraditæ), and Apollinarians when they anathematize every heresy; and sign them with the cross as we say, “The Seal of the gift of the Holy Ghost.  Amen.”

Compare with this Canon vij. of Laodicea, and the so-called vijth. canon of the First Council of Constantinople.

The text I have translated is that ordinarily given, I now present to the reader Hefele’s argument for its worthlessness.

Hefele.

This text is undoubtedly false, for (a) the baptism of the Gnostics was, according to the recognized ecclesiastical principle, invalid, and a Gnostic coming into the Church was required to be baptized anew; (b) besides, it would have us first to require of a Gnostic an anathema on Nestorius, Eutyches, etc.  More accurate, therefore, is the text, as it is given by Beveridge, and as Balsamon had it, to the effect that:  “In the same way (as the preceding) are the Manichæans, Valentinians, Marcionites, and similar heretics to be treated (i.e., to be baptized anew); but the Nestorians must (merely) present certificates, and anathematize their heresy, Nestorius, Eutyches, etc.”  Here we have only this misp. 406 take, that the Nestorians must anathematize, among others, also Eutyches, which they would certainly have done very willingly.  At the best, we must suppose that there is a gap in the text, and that after, “all of similar heresies,” we must add “the later heretics must present certificates and anathematize Nestorius, Eutyches, etc.”

There seems but little doubt that whatever may be the truth in the matter, the early theologians and fathers held that even though the external rite of Holy Baptism might be validly performed by schismatics and heretics, yet that by it the person so baptized did not receive the Holy Ghost, and this opinion was not confined to the East, but was also prevalent in the West.  Vide Rupertus, De Divinis Officiis, Lib. X., Cap. xxv.