Translated by Cardinal Newman.
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 agenetos 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, demiourgein, 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 gennetos and agennetos, 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 agennetos. In the present tract and in Orat. i. 30, he has agenetos 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 agenetos, uncreated or without a 'becoming.' Accordingly although the word gennethenta 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. Haer. 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. S:7, Thilo, ubi supra, Introd. p. 14, and Harnack, Dg. 2, p. 193 note).
De Decretis or Defence of the Nicene Definition
Reference address : https://www.elpenor.org/athanasius/defence-nicene-definition.asp