A dear pastor friend shared with us his insights into the mystery of the Son of God assuming human nature. He writes,
My human nature is not added to who I am. Just as we do not speak in a way that separates our identity/suppositum from our human nature (body and soul), so also in the case of Jesus Christ. The Divine Son is the suppositum who supplies personhood to the human body and soul of Jesus, making him a unified God-man. Therefore, we must neither speak of His divine nature as subtracted nor His human nature added.
This understanding is somewhat new to me, even though I've read James Dolezal's All That Is in God. I used to teach that the incarnation involves not a subtraction of deity but an addition of human nature.1 Yet this view encounters difficulties—much like the idea of a divestment of deity. Thankfully, a friend shared with me a resource that clarified the issue. No contemporary theologian articulates this more clearly than Dr. James Dolezal. His work, Neither Subtraction Nor Addition: The Word's Terminative Assumption of a Human Nature, sheds crucial light on this mystery.2
This concern about divine perfection is one Thomas takes seriously, and he grants the objector's major premise: no addition can be made to that which is already perfect in being. But he does not grant that assumption entails addition. He offers the following reply: "Since the Divine Person is infinite, no addition can be made to it (non potest ei fieri additio): Hence Cyril says: 'We do not conceive the mode of conjunction to be according to addition'; just as in the union of man with God, nothing is added to God by the grace of adoption, but what is Divine is united to man; hence, not God but man is perfected."53 As Thomas says elsewhere, "the person of the Son of God . . . was not in any way augmented or perfected by the assumed human nature."3
Dr. Dolezal provides a helpful illustration to understand this concept of terminative assumption, where the classical theist is not bound to choose between the two problematic options (divestitive and augmentative).
In order to appreciate what motivates the doctrine of terminative assumption, the reasons for rejecting augmentative assumption must be grasped. Several classical theologians deny that the Word's assumption of a human nature involves an addition he makes to himself.4
This understanding of the assumption of human nature aligns with the theology of the high orthodox Reformed theologian Francis Turretin. He argues that
by hypostatic union, by which the Word indeed has assumed a human nature in one hypostasis, but he is not composed with it as part with part. But he has himself toward it as perfecting and sustaining, toward an essential adjunct to be perfected and sustained, so that the human nature thence indeed is perfected, but nothing on that account accedes to the divine nature.5
The reader is encouraged to engage with the full 23-page academic paper to fully grasp the argument Dr. Dolezal presents in correcting these two problematic views. My goal here, however, is more modest: to better understand the truth through the illustrative example he provides. Here's a long quote…
Finally, it will be helpful if we can illustrate what we mean when we speak of termination as requiring neither subtraction nor addition in the terminus. Garrigou-Lagrange, in denying the Word receives anything by assuming a human nature, uses the analogies of a point terminating a line and a seen object terminating one's visual faculty: That the Word possesses the human nature in a receptive sense, this I deny; in a terminative sense, this I concede. To possess a form in a receptive sense is to be the subject of this form, just as matter receives its form, or a substance receives accidental forms; but such is not the case when a subject has some form in a personal or terminative sense. The Word, however, possesses the human nature not in a receptive sense, because He is not in passive potency to receive it; but He possesses it personally and terminatively, in so far as He is its intrinsic terminus, intrinsically completing it and terminating it, just as the point terminates the line, or the object seen terminates the visual faculty.87 A line-segment is perfected or completed by the points that terminate it. But a point is not in any way altered, neither diminished nor enlarged, by its terminative role since points have no length, thickness, or depth; and they are complete in themselves whether or not any line-segment terminates in them. A point receives nothing but a relation of reason in becoming the terminus of some line-segment, even though it becomes intrinsic to the line-segment itself. Point A [and B], for instance, undergoes no change in itself by becoming a terminus for Line-Segment AB. The relation to the point is real in the line-segment; it is only rational in the point. The point really perfects the line-segment in being, but without undergoing any change in itself. The same can be said for visible objects terminating a viewer's vision. The seen object actualizes sight in the viewer's visual faculty, moving it from passive potency to completion in act. In the viewer there is a real relation to the visible object seen; but the seen object receives nothing from the visual faculty it actualizes and terminates. In both of these analogies it should be noted that the terminus perfects the being of that which it brings to completion, and even becomes intrinsic to it, but is not further perfected in itself. And so it is also with the divine Word, who terminates his assumed human nature by perfecting it in being and subsistence, even becoming intrinsic to it and subsisting in it, but is himself utterly undiminished and unimproved by the hypostatic union that results.6
I created a visual illustration to help you easily understand this.
The line segment (AB) is the human nature. The point (B) is the Divine Word (the Eternal Son of God). The line needs the point to be finished/perfected (just like human nature needs a person). But the point doesn't need the line — it stays the same, perfect and unchanged. Jesus didn't "become" a human person by changing who He is. Instead, He united a human nature to Himself, and that human nature is completed or perfected by belonging to Him. It is the human nature that is perfected, not the Eternal Son of God. As God, He is already perfected, pure act, boundless, and full of life.
The seen object — the thing the eye is looking at — stands for the divine Word (the Eternal Son of God). The object doesn't change or receive anything from the eye, but the eye is activated and completed by looking at it. In the same way, when Jesus assumes human nature, the human nature is completed by being united to Him. But the Son of God Himself is not changed or affected by taking on the human nature — He doesn't receive anything or become greater. He simply actualizes it. He is the endpoint (terminus), not a receiver.
In both cases, the terminus (the endpoint, the perfecter) is the Divine Word. The thing that gets completed (line segment or visual faculty) is the human nature. The Word is not changed, but the human nature is perfected by being united to the Word.
In essence, the rejection of "addition" language safeguards the classical understanding of God's absolute perfection, simplicity, and immutability, ensuring that the Incarnation is understood as an act by which the Divine Word exalts human nature by uniting it to His already complete and perfect Person, rather than acquiring anything new or undergoing any intrinsic change.
Any real addition would bring a new perfection of being to the subject and so an infinite being, which as such is unboundedly perfect in being, cannot assume a human nature to itself by way of addition. Infinity and absolute perfection simply cannot be augmented. All augmentation, like all mutation, requires a privation of being in the subject.7
The concept of "terminative assumption" is advanced within classical Christian theology to articulate the Incarnation in a way that is consistent with core doctrines about God's nature, such as divine simplicity, immutability, and impassibility. However, it is crucial to understand that a terminative assumption does not fully resolve or "render comprehensible" the mysteries of the Incarnation. We maintain with Stephen Charnock, "Though we cannot comprehend him as he is, we must be careful not to fancy him to be what he is not."
Soli Deo Trino Gloria!
Footnotes
-
The curious reader can download it freely from Academia. ↩
-
Dolezal, James E. "Neither Subtraction, Nor Addition: The Word's Terminative Assumption of a Human Nature." Nova et vetera, vol. 20 no. 1, 2022, p. 133–157. Project MUSE, https://dx.doi.org/10.1353/nov.2022.0014. ↩
-
Ibid. ↩
-
As quoted by Duby, Steven J. Divine Simplicity. Bloomsbury Publishing, 17 Dec. 2015. 87. ↩
-
Ibid. ↩
-
Ibid. ↩