But since some have attempted to stigmatize even Eusebius Pamphilus himself as having favored the Arian views in his works, it may not be irrelevant here to make a few remarks respecting him. In the first place then he was both present at the council of Nicæa, which defined the doctrine of the homoousion and gave his assent to what was there determined. And in the third book of the Life of Constantine, he expressed himself in these words: The emperor incited all to unanimity, until he had rendered them united in judgment on those points on which they were previously at variance; so that they were quite agreed at Nicæa in matters of faith.' Since therefore Eusebius, in mentioning the Nicene Synod, says that all differences were removed, and that all came to unity of sentiment, what ground is there for assuming that he was himself an Arian? The Arians are also certainly deceived in supposing him to be a favorer of their tenets. But some one will perhaps say that in his discourses he seems to have adopted the opinions of Arius, because of his frequently saying through Christ,
Christianity · Church History · Ecclesiastical History
Book II, Ch. 21 — Defense of Eusebius Pamphilus.
Ecclesiastical History · Socrates Scholasticus