This fragment (Migne xxvi. 1261) is given by Facundus, Def. Tr. Cap. iv. 2, who claims it as addressed to Diodorus of Tarsus, the famous Antiochene confessor and master of Chrysostom and Theodore. Unfortunately this is impossible, as Diodore became bishop of Tarsus not before 378, i.e. after Athan. was dead. The letter itself decides for Diodorus of Tyre, whom Paulinus of Antioch had quite unwarrantably ordained to this see (cf. Rufin, H. E. ii. 21). Whether (as has been held on the authority of Rufinus) Diodorus, or (as Le Quien, Or. Chr. ii. 865 sq. holds) Zeno, the nominee of Meletius, was first in the field in the unseemly scramble, is doubtful. Zeno is already bishop in 365 (Soz. vi. 12); the date of the appointment of Diodorus, whose claim is at any rate no better than that of Paulinus himself, is quite uncertain (see also Prolegg. ch. ii. §§9, 10). Diodorus was the friend and correspondent of Epiphanius, and of Timothy, bishop of Alexandria, second from Athanasius. Facundus confuses him in these particulars also with his namesake of Tarsus, but the mistake is thoroughly sifted by Tillemont, Mem. viii. pp. 238, 712. The letter is important, along with Letter 56, and the correspondence of S. Basil, as illustrating the attitude of Athanasius with regard to the unhappy schism of Antioch.
Editorial footnote · Personal Letters (Robertson translation), Letter 64, editorial note cite_note-1 · Original source