An interesting conclusion can be drawn from David Luy’s ‘Dominus Mortis’. Stated bluntly, the conclusion is this: passibilism, the idea that God suffers, follows the same logic as Nestorianism. That’s an extraordinary claim, but as with all claims, it requires but sufficient evidence.
A bit more precisely, let’s define the passibilist thesis broadly as the idea that the being of God is conditioned by events in salvation history. Here, passibilism is a distinctly historicist thesis, and vice versa. Luy summarizes:
‘God becomes truly vulnerable in Christ by entering into the depths of human corruption. Christ resolves the defects of sinful existence by subsuming them within the historical process of God’s own dialectically mediated self-existence. Those in union with Christ through faith are caught up into the sequential process of divine becoming. In Christ, God identifies God’s own being with sinful humanity. In doing so, God offers them a share in God’s eschatalogical future.’ (Dominus Mortis’, pp. 171)
The semantic logic behind this thesis roughly cashes out to this: If God suffers, divinity suffers. Jesus is God, therefore, divinity suffers. Nestorius, wanting to preserve the integrity of deity (as opposed to simply importing a pagan Greek concept of God, according to Luther), argues that God cannot suffer:
‘Luther does not chastise Nestorius because he assumes that divinity is incapable of suffering. He criticizes the fifth-century bishop for rejecting orthodox christological speech on the basis of faulty logic. Nestorius wrongly assumes that an ascription of human predicates to God must entail a coextensive application of the same predicates to Christ’s divinty. The entailment does not follow. Nestorius’s failure to understand this leads him to speak as if Christ were two distinct persons.’ (pp. 175)
For Luther, this orthodox christological speech was the communication of attributes – that is, the predication of both divine and human attributes to the one person Christ in virtue of his divine and human natures. An example of this would be, say, that God suffers, and a man created the heavens (both of which were said, actually, by Luther and late scholastic theologians). Both of these are true in virtue of the fact that, according to his human nature, Jesus suffered, and according to his divine nature, Jesus created the heavens (rough and oversimplified, of course). Thus, the opposite of the passibilist thesis: God suffers does not entail that divinity suffers. God suffers, not because Jesus and therefore divinity suffers, but because Jesus, the God-Man, is one subject with two natures, of whom we can predicate things both human and divine. Luther here invokes two-natures language as well as the medieval idea of ‘concrete’ predications:
‘We are told here that Christ, true God and born as true man, descended according to His humanity, that God’s son died, descended into hell, and ascended again into heaven; that at the same time God remained in heaven, for the Godhead does not move about hither and thither but is omnipresent; and that according to His human nature, Christ ascended up above all. One may properly say that since there are two natures on one Being and Person, God’s Son came down and entered into the Virgin’s womb and God’s son descended into hell. Although this really applied only to the human nature, by virtue of the personal union in Christ it is also ascribed to the other nature. “That which applies to the one nature, applies to the entire person in the concrete”.’ (‘Luther Works’, 22:328, quoted in ‘Dominus Mortis’, pp. 136)
Luther’s christological semantic here invokes a distinction between ‘abstract’ and ‘concrete’ predicates. It is worth paying close attention to, especially on account of its precedence in medieval scholastic theology:
‘The primary intent of the distinction’s application during this period is to distinguish between predicates that refer to the single person of Christ (concrete) and those that denote each nature as such (abstract). Thomas Aquinas, for instance, distinguishes concrete terms as predications that refer to natures as they are possessed by the subject, whereas abstract terms refer to natures per se. This distinction regulates the grain of christological description for Aquinas and other medieval thinkers. Concrete terms may apply to any subject that possesses the “nature” to which a particular abstract terms belongs. Human properties may therefore be ascribed to the son of God (in the concrete) by virtue of the fact that the humanity of Christ is “possessed”, so to speak, by a divine subject. The predications may not run in reverse. Concrete terms do not necessarily apply to each of Christ’s natures. Hence, the Son of God suffers (abstract to concrete) but divinity does not suffer (concrete to abstract).’ (pp. 151-152)
It should be noted that Luy argues that it is precisely these two ideas, the communication of attributes and concrete/abstract predications, that show Luther did not endorse a bidirectional communication of attributes:
‘Luther’s prolific use of the distinction between abstract and concrete predication…makes it abundantly clear that, despite whatever ambiguities may exist in his descriptive vocabulary, his intent is consistently to affirm the single subjectivity of Christ as the rightful recipient of predicates belonging to the divinity and humanity. In expressing this intent, Luther specifically rejects any notion that the divine nature is directly conditioned by human properties of Christ. He prohibits this implication by enlisting medieval qualificatory discourse. God suffers, for Luther, only in the sense that the one person who is both God and man suffers on account of of his genuine humanity.’ (p. 159)
With the concrete/abstract distinction as well as the communication of attributes in mind, it becomes easier to see just how the passibilist thesis runs on the same logic as Nestorius. Nestorius’s failure to adopt the communication of attributes forces him, on pain of accepting a suffering deity, to refuse predicating human attributes of God:
‘Nestorius imagines that the application of creaturely predicates to God logically demands that Christ’s divinity is ontologically conditioned…He [Luther] agrees that Christ’s divinity is not derived from Mary’s womb. And yet, because Christ is a single person, the predicates of both natures must apply to God. It is thus not Nestorius’s doctrine of God that misleads him, but his lack of logical sophistication.’ (pp. 177)
What Luy takes to be the key consequence is this: by affirming that God suffers, one does not logically have to accept the suffering of divinity. However, if one rejects the idea that God suffers, one must logically reject the incarnation. Because Jesus is truly God and truly man, God suffers. But because Jesus is truly God, divinity does not suffer. Luther argues that Nestorius’s error lies in his semantic – of his refusing to predicate human attributes of God because of his belief that a suffering God = a suffering divinity. The passibilist thesis, which holds that Christ’s suffering = divine suffering, can thus be seen to run on Nestorian logic.