Much will always be obscure about the Council of Nicaea. No stenographic record of the proceedings was taken and no minutes were produced by anyone.
It is true that we have reports of different parts of the debates from four men who attended the council – Constantine himself, Eustathius the bishop of Antioch (frag. 32 Spanneut = Theodoretus, HE 1.8.1-5, cf. Barnes 1978a: 57-59), Eusebius of Caesarea (VC 3.6-22) and Athanasius, who attended as the deacon and assistant of Alexander of Alexandria and composed a very selective account of the council nearly thirty years later in a long letter which he probably addressed to Liberius, who became bishop of Rome on 17 May 352 (De decretis Nicaeni synodi [CPG 2120], cf. Barnes 1993a: 110-112, 198-200).
And later writers who were not at the council provide isolated snippets of information about it. such as that the creed was actually written by the Cappadocian priest Hermogenes (Basil of Caesarea, Epp. 81, 244.9, 263.3). But neither singly nor collectively do any of these provide more than discontinuous glimpses of the course of the debates.
Hang on … the creed was actually written by a Cappadocian priest named Hermogenes? Of course I had to look this up!
The reference is to letter 81 of the letters of Basil of Caesarea. This is online in several translations. It is, in fact, a letter of recommendation for a job, for the son of this Hermogenes. Here’s the NPNF version:
Not then to be at issue with you, but rather to have you on my side in my defence which I make in the presence of Christ I have, after looking round in the assembly of the presbyters of the city, chosen the very honourable vessel, the offspring of the blessed Hermogenes, who wrote the great and invincible creed in the great Synod. He is a presbyter of the Church, of many years standing, of steadfast character, skilled in canons, accurate in the faith, who has lived up to this time in continence and asceticdiscipline, although the severity of his austere life has now subdued the flesh; a man of poverty, with no resources in this world, so that he is not even provided with bare bread, but by the labour of his hands gets a living with the brethren who dwell with him. It is my intention to send him.
In order, therefore, that I may not come into litigation with you, but rather may find in you an associate in my defence before Christ, having looked about in the assembly of the presbyters belonging to this city, I have chosen that most worthy vessel, the offspring of the blessed Hermogenes — who, in the great Synod, wrote the great and invincible creed.
DeFerrari, the translator, adds the notes:
* He was the spiritual offspring of Hermogenes, having been ordained by him. Hermogenes was bishop of Caesarea in Cappadocia and predecessor of Dianius. Cf. Letters CCXLIV, CCLXIII.
* I.e., at Nicaea. Basil seems to forget that it was Leontius who was present at Nicaea as bishop of Caesarea, although Hermogenes may have been present in lower orders, and may have written the creed.
Neither note seems necessary, tho.
But what does the phrase “wrote the creed” (πίστιν γράψαντος) signify? It can’t mean “composed”, but rather “write down”, “note down”, i.e. from the discussion.
All the same, it is interesting to learn of this little piece of information!
If we followed the letter of Eusebius, preserved by Athanasius in De synodis Nicenis, we would suppose that the creed was the same as that which Eusebius offered to the council as his own confession, with only the addition of the word “homoousios” proposed by Constantine himself. But this never sounded very likely. I suspect that the text of Eusebius’ letter has suffered in transmission – probably some paragraphs have been omitted – and consequently misleads us.