Nicene terminology defended by Athanasius of Alexandria in "De Decretis Nicaenae synodi" and the possible influence of Eusebius’ "Epistula ad Caesarienses"

Only two longer ancient narratives can be found in the theological debates at the Council of Nicaea (325) which preceded the subscription of the Nicene Creed. There is firstly a letter by Eusebius, the bishop of Caesarea in Palestine, addressed to Eusebius’ own diocese. In this letter written during the Council or shortly after, Eusebius explained the conditions upon which he was able to agree with the Nicene Creed. Eusebius’ Letter to his Diocese (Epistula ad Caesarienses) contains the first extant theological comments on the Nicene Creed2. Secondly, there is a treatise by the Alexandrian bishop Athanasius On the Decrees of Nicaea (De decretis Nicaenae synodi), composed during the 350s, at least a quarter of a century after the Council at Nicaea3. In this writing, Athanasius argued against the associates of Acacius, a successor of Eusebius in the episcopal see at Caesarea4, and developed the detailed defence of the Nicene terminology, not found in Athanasius’ earlier texts5. As the traditional name of the Athanasius’ writing indicates, De decretis Nicaenae synodi is not