Martin Chemnitz, The Two Natures of Christ, CPH, p. 371
Here, Chemnitz is quoting St. Cyril of Alexandria's, Epistola Synodica ). His book "The Two Natures of Christ" has remained THE standard on the subject in all the world for four and a half centuries. Charles Porterfield Krauth describes Chemnitz thus:
The learning of Chemnitz was something colossal, but it had no tinge of pedantry. His judgment was of the highest order. His modesty and simplicity, his clearness of thought, and his luminous style, his firmness in principle, and his gentleness in tone, the richness of his learning and the vigor of his thinking, have revealed themselves in such measure in his Loci, his Books on the Two Natures of our Lord, and on the True Presence, in his Examen of the Council of Trent, his Defence of the Formula of Concord, and his Harmony of the Gospels, as to render each a classic in its kind, and to mark their author as the greatest theologian of his time – one of the greatest theologians of all time. (Charles Porterfield Krauth, The Conservative Reformation and Its Theology [Philadelphia: General Council Publication Board, 1871], p. 310).
Today we mark his commemoration day of who it was said:
Si Martinus non fuisset, Martinus vix stetisset
"If Martin (Chemnitz) had not come along, Martin (Luther) would hardly have survived"