Athanasius Ad Ant., 3-5

3. The ‘Meletians’ to be acknowledged, and all who renounce heresy, especially as to the Holy Spirit. As many then as desire peace with us, and specially those who assemble in the Old [Church] and those again who are seceding from the Arians, do ye call to yourselves, and receive them as parents their sons, and welcome them as tutors and guardians; and unite them to our beloved Paulinus and his people, without requiring more from them than to anathematise the Arian heresy and confess the faith confessed by the holy fathers at Nicæa, and to anathematise also those who say that the Holy Spirit is a Creature and separate from the Essence of Christ. For this is in truth a complete renunciation of the abominable heresy of the Arians, to refuse to divide the Holy Trinity, or to say that any part of it is a creature. For those who, while pretending to cite the faith confessed at Nicæa, venture to blaspheme the Holy Spirit, do nothing more than in words deny the Arian heresy while they retain it in thought. But let the impiety of Sabellius and of Paul of Samosata also be anathematised by all, and the madness of Valentinian and Basilides, and the folly of the Manichæans. For if this be done, all evil suspicion will be removed on all hands, and the faith of the Catholic Church alone be exhibited in purity.

4. The parties at Antioch to unite. But that we, and they who have ever remained in communion with us, hold this faith, we think no one of yourselves nor any one else is ignorant. But since we rejoice with all those who desire re-union, but especially with those that assemble in the Old [church], and as we glorify the Lord exceedingly, as for all things so especially for the good purpose of these men, we exhort you that concord be established with them on these terms, and, as we said above, without further conditions, without namely any further demand upon yourselves on the part of those who assemble in the Old [church], or Paulinus and his fellows propounding anything else, or aught beyond the Nicene definition.

5. The creed of Sardica not an authorised formula. Question of ‘hypostasis.’ And prohibit even the reading or publication of the paper, much talked of by some, as having been drawn up concerning the Faith at the synod of Sardica. For the synod made no definition of the kind. For whereas some demanded, on the ground that the Nicene synod was defective, the drafting of a creed, and in their haste even attempted it, the holy synod assembled in Sardica was indignant, and decreed that no statement of faith should be drafted, but that they should be content with the Faith confessed by the fathers at Nicæa, inasmuch as it lacked nothing but was full of piety, and that it was undesirable for a second creed to be promulged, lest that drafted at Nicæa should be deemed imperfect, and a pretext be given to those who were often wishing to draft and define a creed. So that if a man propound the above or any other paper, stop them, and persuade them rather to keep the peace. For in such men we perceive no motive save only contentiousness. For as to those whom some were blaming for speaking of three Subsistences, on the ground that the phrase is unscriptural and therefore suspicious, we thought it right indeed to require nothing beyond the confession of Nicæa, but on account of the contention we made enquiry of them, whether they meant, like the Arian madmen, subsistences foreign and strange, and alien in essence from one another, and that each Subsistence was divided apart by itself, as is the case with creatures in general and in particular with those begotten of men, or like different substances, such as gold, silver, or brass;—or whether, like other heretics, they meant three Beginnings and three Gods, by speaking of three Subsistences. They assured us in reply that they neither meant this nor had ever held it. But upon our asking them ‘what then do you mean by it, or why do you use such expressions?’ they replied, Because they believed in a Holy Trinity, not a trinity in name only, but existing and subsisting in truth, ‘both a Father truly existing and subsisting, and a Son truly substantial and subsisting, and a Holy Spirit subsisting and really existing do we acknowledge,’ and that neither had they said there were three Gods or three beginnings, nor would they at all tolerate such as said or held so, but that they acknowledged a Holy Trinity but One Godhead, and one Beginning, and that the Son is coessential with the Father, as the fathers said; while the Holy Spirit is not a creature, nor external, but proper to and inseparable from the Essence of the Father and the Son.