John of Damascus: Exposition of the Orthodox Faith 50That in one of its subsistences the divine nature is united in its entirety to the human nature, in its entirety and not only part to part.

What is common and general is predicated of the included particulars. Essence, then, is common as being a form, while subsistence is particular. It is particular not as though it had part of the nature and had not the rest, but particular in a numerical sense, as being individual. For it is in number and not in nature that the difference between subsistences is said to lie. Essence, therefore, is predicated of subsistence, because in each subsistence of the same form the essence is perfect. Wherefore subsistences do not differ from each other in essence but in the accidents which indeed are the characteristic properties, but characteristic of subsistence and not of nature. For indeed they define subsistence as essence along with accidents. So that the subsistence contains both the general and the particular, and has an independent existence, while essence has not an independent existence but is contemplated in the subsistences. Accordingly when one of the subsistences suffers, the whole essence, being capable of suffering, is held to have suffered in one of its subsistences as much as the subsistence suffered, but it does not necessarily follow, however, that all the subsistences of the same class should suffer along with the suffering subsistence.

Thus, therefore, we confess that the nature of the Godhead is wholly and perfectly in each of its subsistences, wholly in the Father, wholly in the Son, and wholly in the Holy Spirit. Wherefore also the Father is perfect God, the Son is perfect God, and the Holy Spirit is perfect God. In like manner, too, in the Incarnation of the Trinity of the One God the Word of the Holy Trinity, we hold that in one of its subsistences the nature of the Godhead is wholly and perfectly united with the whole nature of humanity, and not part united to part. The divine Apostle in truth says that in Him dwelleth all the fulness of the Godhead bodily, that is to say in His flesh. And His divinely-inspired disciple, Dionysius, who had so deep a knowledge of things divine, said that the Godhead as a whole had fellowship with us in one of its own subsistences. But we shall not be driven to hold that all the subsistences of the Holy Godhead, to wit the three, are made one in subsistence with all the subsistences of humanity. For in no other respect did the Father and the Holy Spirit take part in the incarnation of God the Word than according to good will and pleasure. But we hold that to the whole of human nature the whole essence of the Godhead was united. For God the Word omitted none of the things which He implanted in our nature when He formed us in the beginning, but took them all upon Himself, body and soul both intelligent and rational, and all their properties. For the creature that is devoid of one of these is not man. But He in His fulness took upon Himself me in my fulness, and was united whole to whole that He might in His grace bestow salvation on the whole man. For what has not been taken cannot be healed.

The Word of God, then, was united to flesh through the medium of mind which is intermediate between the purity of God and the grossness of flesh. For the mind holds sway over soul and body, but while the mind is the purest part of the soul God is that of the mind. And when it is allowed by that which is more excellent, the mind of Christ gives proof of its own authority, but it is under the dominion of and obedient to that which is more excellent, and does those things which the divine will purposes.

Further the mind has become the seat of the divinity united with it in subsistence, just as is evidently the case with the body too, not as an inmate, which is the impious error into which the heretics fall when they say that one bushel cannot contain two bushels, for they are judging what is immaterial by material standards. How indeed could Christ be called perfect God and perfect man, and be said to be of like essence with the Father and with us, if only part of the divine nature is joined in Him to part of the human nature?

We hold, moreover, that our nature has been raised from the dead and has ascended to the heavens and taken its seat at the right hand of the Father: not that all the persons of men have risen from the dead and taken their seat at the right hand of the Father, but that this has happened to the whole of our nature in the subsistence of Christ. Verily the divine Apostle says, God hath raised us up together and made us sit together in Christ.

And this further we hold, that the union took place through common essences. For every essence is common to the subsistences contained in it, and there cannot be found a partial and particular nature, that is to say, essence: for otherwise we would have to hold that the same subsistences are at once the same and different in essence, and that the Holy Trinity in respect of the divinity is at once the same and different in essence. So then the same nature is to be observed in each of the subsistences, and when we said that the nature of the word became flesh, as did the blessed Athanasius and Cyrillus, we mean that the divinity was joined to the flesh. Hence we cannot say "The nature of the Word suffered;" for the divinity in it did not suffer, but we say that the human nature, not by any means, however, meaning all the subsistences of men, suffered in Christ, and we confess further that Christ suffered in His human nature. So that when we speak of the nature of the Word we mean the Word Himself. And the Word has both the general element of essence and the particular element of subsistence.