Apropos to the feast of St. Mark of Ephesus

…may the Lord deliver us from such delusion: and may there be given to you a hatred against the serpent, that as they lie in wait for the heel, so you may trample on their head.
St. Cyril of Jerusalem

Middle doctrine

'Many were tempted by the idea,' [St.] Mark [of Ephesus] continued, 'that one can find a medium between two doctrines. True: one can find such expressions which, having a double meaning, could at the same time express something between the two doctrines. But a doctrine midway between two contrary doctrines on the same subject is impossible; for in this case it must be something between truth and falsehood, between an affirmation and a negation. Thus, if the Latin doctrine of the Spirit’s procession from the Son is just, then ours is false. What middle doctrine can there be here?'

Orthodoxy...

...We see from all this that we teach conformably with Holy Scripture, and the holy Fathers, and Teachers, nothing changing or misrepresenting in the dogmas handed down to us, nothing adding to them, or taking from them, and adding nothing new.
St. Mark of Ephesus

Apropos to the "Afterfeast" of St. Mark of Ephesus

The Patriarch also had an interview with Mark, and entreated him in the name of all the Saints, and for the sake of his father's memory, to agree to the union with the Church of Rome. But this venerable man remained firm against all entreaties. He had already been asked to agree to union, even if it were apparently for the sake of others. His answer was: "In deeds of faith there must be no concessions, no waverings." And when the difference between the two confessions was shown as insignificant, Mark answered: "You speak just like the prefect, who entreated Theodorus to receive heretics into communion only once, and then to act as he liked." The saint answered: "Thy request is like, as if a person said, Allow me to cut your head off, and then you may go wherever you like." Following up this example, Mark remained firm to the end.

Apropos to the feast of St. Mark of Ephesus

From the interview of St. Mark with Pope Eugenius:

The Councils of the Church have condemned as rebels those who have transgressed against some dogma and have preached thus and fought for this, for which reason also they are called 'heretics'; and from the beginning the Church has condemned the heresy itself, and only then has it condemned the leaders of the heresy and its defenders. But I have by no means preached my own teaching, nor have I introduced anything new in the Church, nor defended any foreign and false doctrine; but I have held only that teaching which the Church received in perfect form from our Saviour, and in which it has steadfastly remained to this day: the teaching which the Holy Church of Rome, before the schism that occurred between us, possessed no less than our Eastern Church; the teaching which, as holy, you formerly were wont to praise, and often at this very Council you mentioned with respect and honor, and which no one could reproach or dispute. And if I hold it and do not allow myself to depart from it, what Council will subject me to the interdiction to which heretics are subject? What sound and pious mind will act thus with me? For first of all one must condemn the teaching which I hold; but if you acknowledge it as pious and Orthodox, then why am I deserving of punishment?