St. Gregory the Theologian on the Two Natures of Christ

St. Gregory the Thelogian ca. 329-389

And (if I am to speak concisely) the Saviour is made of elements which are distinct from one another (for the invisible is not the same with the visible, nor the timeless with that which is subject to time), yet He is not two Persons. God forbid! For both natures are one by the combination, the Deity being made Man, and the Manhood deified or however one should express it. And I say different Elements, because it is the reverse of what is the case in the Trinity; for There we acknowledge different Persons so as not to confound the persons; but not different Elements, for the Three are One and the same in Godhead.

Keep then the whole man, and mingle Godhead therewith, that you may benefit me in my completeness. But, [Apollinaris] asserts, “He could not contain Two perfect Natures.” Not if you only look at Him in a bodily fashion. For a bushel measure will not hold two bushels, nor will the space of one body hold two or more bodies. But if you will look at what is mental and incorporeal, remember that I in my one personality can contain soul and reason and mind and the Holy Spirit; and before me this world, by which I mean the system of things visible and invisible, contained Father, Son, and Holy Ghost. For such is the nature of intellectual Existences, that they can mingle with one another and with bodies, in corporeally and invisibly. For many sounds are comprehended by one ear; and the eyes of many are occupied by the same visible objects, and the smell by odours; nor are the senses narrowed by each other, or crowded out, nor the objects of sense diminished by the multitude of the perceptions. But where is there mind of man or angel so perfect in comparison of the Godhead that the presence of the greater must crowd out the other? The light is nothing compared with the sun, nor a little damp compared with a river, that we must first do away with the lesser, and take the light from a house, or the moisture from the earth, to enable it to contain the greater and more perfect. (Epistle 101: To Cledonius)