This letter must have been written in the interval between the return of Athanasius in 346 and his flight in 356. Acacius was already (§3) Bishop of Caesarea 339; Eusebius of Nicomedia is not referred to as though still living (he died 342). Moreover the language of §2 ("for in no long time they will turn to outrage," &c.) implies a period of actual peace, but with a prospect of the repetition of the scenes of the year 339. This actually occurred in 356. Accordingly we must probably place the tract under the sole reign of Constantius, between 351 and the end of 355.
It is written in answer to a friend who in disputing with Arians had been posed by their objection to the use of non-scriptural terms in the Nicene Definition. He accordingly asks for some account of what the council had done.
Athanasius begins his answer by stigmatising the evasions and inconsistency of the Arianisers, and describing their conduct at the council, and how they eventually subscribed to the terms now complained of (1-5). He then investigates the meaning of the divine Sonship (6-14), and how its true meaning is brought out by the other titles of the Son 15-17). Coming to the non-scriptural expressions he shews how they were forced upon the council by the evasions of the Arians (18-20), and that they express no sense not to be found in Scripture (21-24). Moreover, they had already been in use in the Church, as is shewn by extracts from Theognostus, the two Dionysii, and Origen (25-27). Lastly (28-32) he discusses the term agenhtoj, applied by the Arians (especially Asterius) to the Father, in contrast, not to the creation, but to the Son, who is thereby implied to be genhtoj. He insists on `Father' not `agenhtoj' as the divine title authorised by Scripture. Lastly he appends, in proof of what he states in §3, the letter of Eusebius to the people of Caesarea, containing the creed of the council, which, for reasons there stated, we have inserted above, pp. 73-76.
The interest of the letter is principally threefold; first on account of its notice of the proceedings at Nicaea (cf. ad Afr. 5), one of the few primary sources of our knowledge of what took place there: secondly, on account of its fragments of early writers, especially the Dionysii, of whom more will be said in the introduction to the next tract. With regard to Theognostus, the quotations in this tract and in Serap. iv. 9 are important in view of the somewhat damaging accounts of his teaching in the few other writers (Gregory of Nyssa, Photius) who mention him.
Thirdly, the term agenhtoj demands attention. It is impossible to give its exact force in idiomatic English: the rendering `Ingenerate' adopted by Newman is perhaps the most unfortunate one imaginable. `Uncreated,' a possible substitute, is also open to objection, firstly, as not distinguishing the word from the derivatives of ktizein, poiein, dhmiourgein, secondly, as giving it a passive sense, which does not inherently attach to it. For lack of a better word, `Unoriginate' may perhaps be adopted. `That which has not (or cannot) come to be,' `that which is not the result of a process,'-is what the word strictly signifies'-`das Ungewordene.' It was therefore strictly applicable to the Son as well as to the Father. But throughout the earlier stages of the Arian controversy the question was embarrassed by the homophones gennhtoj and agennhtoj, generate or begotten, and unbegotten. The confusion of thought due to the resemblance of sound is reflected in the confusion of readings in the mss. Athanasius himself (Orat. i. 56) perceives the distinctive sense of agennhtoj. In the present tract and in Orat. i. 30, he has agenhtoj only in view, the idea of begetting being absent. Here (and cf. de Syn. 46, note 5) he is denying that the Father is alone agenhtoj, uncreated or without a `becoming.' Accordingly although the word gennhqenta was consecrated and safeguarded in the Creed of Nicaea (Begotten not made), and although the distinctness of the derivatives of the two verbs was felt by Athanasius, and pointed out by others (Epiph. Hoer. 64, 8), the use of either group of words was avoided by Catholics as dangerous. A clear distinction of the words and of their respective applicability is made by John Damascene Fid. Orth. I. viii. (see Lightfoot, Ignat. vol. 2, excursus on Eph. §7, Thilo, ubi supra, Introd. p. 14, and Harnack, Dg. 2, p. 193 note).