ON THE PERSONAL UNION OF THE TWO

ERIST. I know that you posit a verbal communication of properties, and, as I said, I oppose it.

ORTH. If you weigh the matter rightly, whatever this doctrine may be, you will by no means be able to censure it unless you abjure the truth. Since, therefore, the eternal Son of God united human nature to himself by a wondrous covenant so that now God and man are one person, and there are two entire and distinct natures in this one person, each of which preserves its essential properties safe and unconfused: from this it follows by inevitable conclusion that we neither must nor can speak of this mystery other than as the thing itself, as it is in itself, permits. For these modes of speaking declare what was done, so that those who deny what was done may be refuted, or [so that those who] mix into this mystery of the incarnation something that was not done and has not been handed down by divine voice [may be refuted]. Because there is one person, not two, the speech must also be fashioned so that we are not perceived to be speaking of multiple persons. On the other hand, since there are two natures, and there are two distinct essences and essential properties and operations of the same, and not one nature, property, or operation, one must pronounce concerning them in such a way that we either encompass the concrete, or, if we are about to speak of either nature, we assign to each its own property, from which the nature can be recognized; so that, if we either take away what is due or attribute what is repugnant to either, we are not rendered prevaricators against the person of Christ. This custom we see both Holy Scripture and the orthodox Church to have observed piously and learnedly.

The communicatio idiomatum, which is so called in the Church, is such a predication or form of speaking in which a property suitable to one nature is attributed to the person in the concrete, because these two natures, the Logos Word and the assumed nature, are one hyphistamenon subsistent; and it does not escape you what dialecticians mean by the word "concrete" and what they mean by "abstract."

Things are called abstract when we encompass and contemplate the very nature and forms of things by themselves