Continuing with John’s Exposition of the Orthodox Faith, we read about the unity of the Godhead. Now it must be understood that our contemporary manner of speaking, with clear and easy references to “the essence” and “the persons” is not the positive methodology of John. He certainly distinguishes between ousia and hypostasis, but he also makes reference to the nature (physis) and the energy. There is also the concept of names which will come up later. Rather than simply using our modern notion of “essence,” it is better to speak of “the unity.” The value of paying attention to the unity will become clear.
John writes:
And this may be perceived throughout the whole of creation, but in the case of the holy and superessential and incomprehensible Trinity, far removed from everything, it is quite the reverse. For there the community and unity are observed in fact, through the co-eternity of the subsistences, and through their having the same essence and energy and will and concord of mind, and then being identical in authority and power and goodness—I do not say similar but identical—and then movement by one impulse. For there is one essence, one goodness, one power, one will, one energy, one authority, one and the same, I repeat, not three resembling each other. But the three subsistences have one and the same movement. For each one of them is related as closely to the other as to itself: that is to say that the Father, the Son, and the Holy Spirit are one in all respects, save those of not being begotten, of birth and of procession. But it is by thought that the difference is perceived. For we recognise one God: but only in the attributes of Fatherhood, Sonship, and Procession, both in respect of cause and effect and perfection of subsistence, that is, manner of existence, do we perceive difference. For with reference to the uncircumscribed Deity we cannot speak of separation in space, as we can in our own case. For the subsistences dwell in one another, in no wise confused but cleaving together, according to the word of the Lord, I am in the father, and the father in Me: nor can one admit difference in will or judgment or energy or power or anything else whatsoever which may produce actual and absolute separation in our case. Wherefore we do not speak of three Gods, the Father, the Son, and the Holy Spirit, but rather of one God, the holy Trinity, the Son and Spirit being referred to one cause, and not compounded or coalesced according to the synæresis of Sabellius. For, as we said, they are made one not so as to commingle, but so as to cleave to each other, and they have their being in each other without any coalescence or commingling. Nor do the Son and the Spirit stand apart, nor are they sundered in essence according to the diæresis of Arias. For the Deity is undivided amongst things divided, to put it concisely: and it is just like three suns cleaving to each other without separation and giving out light mingled and conjoined into one. When, then, we turn our eyes to the Divinity, and the first cause and the sovereignty and the oneness and sameness, so to speak, of the movement and will of the Divinity, and the identity in essence and power and energy and lordship, what is seen by us is unity.
~1.8
What is of interest here is John’s statement that “the difference is perceived” only in “the manner of existence.” It should not be difficult to understand how Thomas Aquinas could make such use of the Damascene, as well as Pseudo-Denys. The “Person” is a “manner of existence,” and this is also a relationship of “cause and effect”: Sonship and Procession. There is much to say about this language of “cause and effect,” and John is clear that this has nothing to do with priority of time or nature. It is only an ordering of relation.
To show that this is indeed what Western thinkers mean by God’s essence, we need to notice John’s language of “one motion.” In the Trinity:
the community and unity are observed in fact, through the co-eternity of the subsistences, and through their having the same essence and energy and will and concord of mind, and then being identical in authority and power and goodness—I do not say similar but identical—and then movement by one impulse. For there is one essence, one goodness, one power, one will, one energy, one authority, one and the same, I repeat, not three resembling each other. But the three subsistences have one and the same movement.
John does not merely use the term “essence” or “nature,” but he does include these, as well as will, mind, power, energy, and other descriptions under the category of “unity.” He concludes:
When, then, we turn our eyes to the Divinity, and the first cause and the sovereignty and the oneness and sameness, so to speak, of the movement and will of the Divinity, and the identity in essence and power and energy and lordship, what is seen by us is unity.
When we turn our eyes to the Divinity, what is seen by us is unity.
