Arius the namesake of madness
Eustathius is addressing Emperor Constantine and has just urged him to keep the faith walled about and let no heretic dishonor any person of the Trinity; now he names Arius as the source of the present disturbance.
Arius is the one responsible for this word and this gathering—the namesake of the madness. Somehow, without our knowing how, he was enrolled in the presbytery of the Church of the Alexandrians, and he escaped our notice, though he was a stranger to the teaching of the thrice-blessed prophets and apostles. He is not ashamed to rob the only-begotten Son and Word of the Father of his consubstantiality with the Father, and this worshiper of what is created is eager to number the Creator together with creation.
Greek
Ἄρειος ἡμῖν ὁ τῆς μανίας ἐπώνυμος τοῦ λόγου καὶ τῆς συνελεύσεως αἴτιος· ὃς, ὡς οὐκ ἴσμεν ὅπως, τῷ πρεσβυτερίῳ τῆς Ἀλεξανδρέων ἐγκαταλεγεὶς Ἐκκλησίας, ἐλάνθανεν ἡμᾶς, τῆς τῶν τρισμακαρίων προφητῶν καὶ ἀποστόλων διδασκαλίας ὑπάρχων ἀλλότριος. Τὸν γὰρ μονογενῆ Υἱὸν καὶ Λόγον τοῦ Πατρὸς ἀποστερεῖν τῆς ὁμοουσιότητος τοῦ Πατρὸς οὐκ ἐντρέπεται, καὶ τῇ κτίσει τὸν κτίστην ὁ κτιστολάτρης συναριθμεῖν ἐπείγεται.