II. Maximus is to keep the churches of the East free from these two opposite heresies.
And therefore, beloved brother, you must with all your heart consider over which church the Lord has set you to preside, and remember that system of doctrine of which the chief of all the Apostles, the blessed Peter, laid the foundation, not only by his uniform preaching throughout the world, but especially by his teaching in the cities of Antioch and Rome: so that you may understand that he demands of him who is set over the home of his own renown those institutions which he handed down, as he received them from the Truth Itself, which he confessed. And in the churches of the East, and especially in those which the canons of the most holy Fathers at Nicæa assigned to the See of Antioch, you must not by any means allow unscrupulous heretics to make assaults on the Gospel, and the dogmas of either Nestorius or Eutyches to be maintained by any one. Since, as I have said, the rock (petra) of the Catholic Faith, from which the blessed Apostle Peter took his name at the Lord's hands, rejects every trace of either heresy; for it openly and clearly anathematizes Nestorius for separating the nature of the Word and of the flesh in the blessed Virgin's conception, for dividing the one Christ into two, and for wishing to distinguish between the person of the Godhead and the person of the Manhood: because He is altogether one and the same who in His eternal Deity was born of the Father without time, and in His true flesh was born of His mother in time; and similarly it eschews Eutyches for ignoring the reality of the human flesh in the Lord Jesus Christ, and asserting the transformation of the Word Himself into flesh, so that His birth, nurture, growth, suffering, death and burial, and resurrection on the third day, all belonged to His Deity only, which put on not the reality but the semblance of the form of a slave.
But maybe I'm not understanding what's being talked about here...
