|Council of Ephesus in 431, in the Basilica of Fourvière, Lyon|
The Pope summoned a Council to meet at Ephesus to deal with the teaching of Nestorius, and appointed St. Cyril as his Legate. More than two hundred Bishops assembled at Ephesus. Amongst them was Nestorius, surrounded by a bodyguard of soldiers which he had demanded of the Emperor. Three times summoned, the heretic refused to leave his lodgings, so the Council was compelled to proceed in his absence.
In the Council of Ephesus three stages may be distinguished; in the first the writings of Nestorius were read and set in contrast with the teaching of the Fathers, in the second we find the great discourse of St. Cyril, and in the last the sentence of the Pope promulgated by his Legate and proclaimed by the Bishops in definitive sentence and decree.
Before the Council St. Cyril had written to monks in Egypt:
"I do not know how to express my astonishment when I, see Christians hesitating to give the Holy Virgin the title of Mother of God. Since our Lord Jesus Christ is God, how can the Virgin, who gave Him birth, not be the Mother of God ? The Apostles have taught us this truth, even though the word Theotokos be not found in their writings. The Holy Fathers never hesitated to use the term. . . .
You may perhaps ask me: ' Was, then, the Holy Virgin Mother of the Divinity ?' We know that the Eternal Word existed before Mary, and that from all Eternity He abides in the Bosom of His Father. But in the Incarnation there is a Mystery, which we can in some measure compare to that of human generation. All men who have ever been born are made up of soul and body. Our mothers gave us the corporal substance into which God has infused a soul. This fact does not hinder us from saying that they gave birth to a man. . . . The union of soul and body makes up the one person who is called the man, therefore she who gives birth to a man is truly his mother. After the same manner that the soul is united so strictly to the body—so indissolubly that one cannot separate them in the human person without destroying the man—in the Incarnation the Word was united to Human Nature to be born in the one and Indivisible Person of Jesus Christ our Lord and God." (Epist, P.G., Tom. LXXVII., Cols. 1-40, passim.)