In this post I’d like to propose two theses for the use of christological language of ‘persons’ and ‘natures.’ Apologies to all that this post is long and rather technical, but writing it has helped me to sort it out a bit for myself, and hopefully the one or two of you out there who are also interested in Christology will find it of some use. I don’t think either point is particularly controversial, although both challenge the way that theologians tend to speak about what Christ has done as Mediator, one who is fully God and fully human.

I

One of the more ‘metaphysical’ insights in the doctrine of the incarnation that the Protestant scholastics clued in on is what I will call the functional distinction between the Chalcedonian categories of persons and natures (or essences). In short: only persons are acting subjects, who perform acts (like healing a blind man) and have acts done to them (like being crucified).

A corollary to this is that only persons may properly be the object of adjectival predication. For example: strictly speaking, Christ’s divine nature is not “eternal,” but rather having a divine nature means that Christ himself has the attribute of being eternal. (There are exceptions here, in that some predicates are fitting to natures — such as ‘assumption.’  But I’d wager that all such examples we could come up with would have direct reference to the person in whom that nature subsists.)

Natures, on the other hand, do not act and may not properly be objects of verbal (in the grammatical sense) predication.  It is not proper to the metaphysics of Chalcedon to say that divine nature ‘creates,’ or that human nature ‘sleeps.’ A nature is, generally speaking, a summation of all attributes essential that that sort of being — a dialogical shorthand for talking about one kind of being in distinction from others.  (One may, therefore, predicate an adjective of a nature — “divine nature is eternal” — since what we are doing here is effectively calling out one attribute that is important to the description of that nature as a representative of the whole construct.)

Let’s call this the ‘formal logic‘ of Chalcedon. Persons, not natures, act.

Now this rule for theological grammar gets pushed aside all the time by the fluidity of the way we use language, in conversation but also in more precise works of theology. My point is that we should be attentive to the fact that such use is improper to the way in which the historic confessions have defined persons, natures, and the relationship of subsistence. Activity is located on the level of personal subjectivity, not on the level of the attributes that describe the subject.

The result of being careful with this distinction is that Christian theology may say, for example, that “Christ died” but not that “Christ’s human nature died.” It is metaphysically impermissible to predicate the verb ‘to die’ of a nature, because natures are themselves predicates.

II

Grunewald's Christ (Isenheim Alterpiece Detail)

This restriction on the use of ‘nature’ language is critical when it comes to applying the doctrine of the two natures of Christ to the biblical narrative and working out the complex problems of his ‘theanthropic’ (divine-human) life. The church has rightly insisted that when Jesus Christ does something — whether it is a divinely-colored miracle, such as walking on water, performing a healing or an exorcism, or multiplying the loaves and fishes; or a very mortal-looking activity, such as walking, sleeping, weeping, or dying — he does it in his full, theandric unity. His humanity is not watching from the sidelines when he works a miracle; divinity doesn’t take a timeout when he is nailed to the cross. Jesus Christ, vere Deus vere homo, is the subject of all of these acts.

What do we make, then, of Chalcedon’s basic insistence that the two natures of Christ are united yet distinguishable? The Council teaches that humanity and divinity are united “without division or separation” but also “without confusion or change.” In other words, though the unity obtains ‘all the way down,’ the two natures don’t lose their distinctives or alter one another, nor are they combined into a third thing. Likewise, what is rightly predicated of one nature (e.g. mortality) is not therefore rightly predicated of the other nature. It is, however, rightly predicated of the theandric person. So, for example, if we say that Jesus’ human nature is mortal we can (and must!) also say that Jesus (simiplicter) is mortal. (We do not, however, invoke some transitive property and say that his divine nature is mortal.)

This is the ‘material logic‘ of Chalcedon, which we should note applies the formal logic of what ‘persons’ and ‘natures’ are, and how they may be interrelated viz. the language of predication.

A too-common mishandling of this principle of unity-in-distinction is to use it as license to predicate acts of Christ to his existence according to just one nature — as if, functionally, for the sake of that act Christ has only one nature and not two. An example can be spotted in James Anderson’s post this week at the Gospel Coalition blog. Addressing the question of whether the incarnation brought about a change in God’s being, Anderson writes:

According to the Definition of Chalcedon, Jesus Christ is one person with two natures, a perfect divine nature and a perfect human nature, and while those natures are united in one person they must nevertheless be distinguished. The properties of each nature can be ascribed to the one person, Jesus Christ, but not necessarily to the other nature.

So, for example, we’re told that Jesus was omniscient (John 16:30) but also that he increased in wisdom (Luke 2:52). To be precise, however, we should say that Jesus was omniscient with respect to his divine nature and gained wisdom with respect to his human nature. On this basis, it seems natural to say that God the Son is timeless and unchangeable with respect to his divine nature but temporal and changeable with respect to his human nature. Since Jesus’ death and resurrection pertained to his human nature, this standard Christological distinction suggests a way to reconcile the events of Jesus’ life with the immutability of God.

On the surface, this approach seems to adhere to the formal rule that natures do not act, arguing instead that the person of Christ acts in one nature or according to one nature (and, by implication, not the other). This is an extremely common way of speaking about the incarnation (so apologies to Dr. Anderson for picking on him). Its pedigree begins with none less than Leo the Great, whose Tome is a seminal document from the Council of Chalcedon. Leo writes:

Each ‘form’ [nature] does the acts which belong to it, in communion with the other; the Word, that is, performing what belongs to the Word, and the flesh carrying out what belongs to the flesh; the one of these shines out in miracles, the other succumbs to injuries.

In my doctoral thesis I hope to demonstrate in more depth just why I think such ‘prepositional’ language (in, according to, with respect to) is problematic.  It merely pushes the activity predicated of a nature back under the shield of the ‘person,’ in order to cohere with the rules of Chalcedon’s formal logic. In doing so, however, it runs the risk of transgressing the material logic of the confession — that what is true of the person with respect to one nature is also true of that person simpliciter (or, in his divine-human unity).

When used well, what prepositional language does for us is to specify that Jesus is able to do this or that by virtue of an attribute which is proper to one of his natures. Omniscience is proper only to his divine nature, so what Anderson ought to have in mind in the quotation above is that Jesus knows all things because this is an attribute of divine nature, which he possesses.  But the emphasis in this affirmation ought to be on Jesus, the acting person (who also has another nature, one that happens to lack the attribute of omniscience), and not on the divine nature. Otherwise we’ve slipped subtly back into the idea that natures act, only camouflaged under an apparently right use of formal logic. In my experience, the strong use of prepositional language does tend to emphasize the nature by which “Jesus” is being qualified — particularly with respect to the difficult questions of his suffering and death, which challenge our understanding of deity.

When we specify that “Jesus is omniscient with respect to his divine nature,” are we uncomfortable also saying “Jesus is omniscient” without qualification?

III

In sum: To say that the theandric person of Jesus Christ ever acts according to one nature but not the other in fact sacrifices the formal logic of Chalcedon, with appeal to the material logic (“without confusion”) as justification.  It divides the person of Christ either by predicating an act of a nature but not of the person simpliciter, or (less likely) by speculatively positing that Jesus has the unique ability to exclude one of his natures from an act.  The use of the language of predication here is simply all wrong.

A set of examples illustrates the various distinctions I am drawing:

  • Good:  “Jesus died.” (person as subject)
  • Bad: “Jesus’ humanity died.” (nature as subject)
  • Good: “Jesus died with respect to his human nature.” (nature provides the person with the predicate of ‘able to die’)
  • Bad: “Jesus died only with respect to his human nature.” (divides the unity of natures and, ultimately, really only wants to predicate death of the nature and not the theandric person)
  • Bad: “Jesus died with respect to his divine nature, too.” (‘able to die’ is improper to divinity)
  • Good: “Jesus (simpliciter) died.” (without the qualification of either nature, this is still true of the theandric person)
  • Good: “The God-man died.” (still accurate — doesn’t predicate death of the divine nature itself, but of the one who has a divine nature)
  • “God the Son died.” (Good or Bad? I’ll leave that up for the comments thread.)

To recap, I’ve offered two theses for your consideration:

  1. According to the metaphysics of classic orthodoxy, persons and not natures are acting subjects. Natures are linguistic constructs by which we summarize essential attributes, and of themselves can neither act nor be acted upon. Natures subsist in persons; and persons can act with respect to natures. This is the formal logic of Chalcedon.
  2. The two natures of Christ exist in a relation of unity-in-distinction, “without division or separation” and “without confusion or change.”  What is true of one nature is therefore true of the person in whom that nature subsists, but not of the other nature. However, this distinction of natures does not give us license to predicate acts of the person with respect to only one nature and not also to the person simpliciter. This is the material logic of Chalcedon.

And that, my friends, is far more technical than anyone should be on a blog. I won’t blame you for not commenting, and next week I’ll write something about worship music or the effects of My Little Pony on our daughters.