Thus far we have been considering the logical puzzle of how an omniscient God could possibly become a human being. The basic problem we face is one of incompossibility of properties: i.e. there are many properties that Christians believe God exemplifies of necessity which are incompatible with attributes human beings exemplify. (Note I haven't yet said that human beings exemplify these properties of necessity. More on that in a subsequent post.) And our sample contradiction thus far has been concerned with the incompossibility of divine omniscience and human ignorance.
We noted that the Gospel of Luke describes Jesus learning, a fact which entails that he was not omniscient. This is coupled by the inconceivability of a blastocyst (or even a full term fetus, or even a toddler!) being omniscient. Thus we seem forced into a dilemma. If Jesus did not exemplify an essential attribute of deity then how could the incarnation possibly be true?
Many theologians have invoked a response to this dilemma which is known as "reduplicative predication". One begins by admitting that it is contradictory to say, without qualification, that Jesus was simultaneously ignorant and omniscient. But then reduplicative predication comes to the rescue by proposing that you can reduplicate your predications, that is qualifying each with respect to the human or divine nature. In other words, you cannot say
Jesus was ignorant
Jesus was omniscient
because this is obviously contradictory. But supposedly you can say:
With respect to (or qua) his human nature Jesus was ignorant
With respect to (or qua) his divine nature Jesus was omniscient
And presumably you can repeat this same method for every potential contradiction. Qua his human nature Jesus was peccable, temporal and weak, but qua his divine nature he was impeccable, atemporal and omnipotent.
Although this remains a popular solution to the paradoxes (or contradictions) of incarnation, it seems to me to be unworkable for a simple reason: insofar as it makes any sense it leads to Nestorianism.
"What is Nestorianism Tentative Apologist?"
Good question. It is a heresy that arose in the fifth century which posited two agents in the incarnation. In other words, Nestoriansm responded to the problems of incarnation by saying that "God became flesh" means that the Son of God united in an intimate way with the man Jesus, but not that the Son of God became the man Jesus.
"So how does reduplicative predication lead to Nestorianism?"
Let's begin by defining the concept of nature. A "nature" is merely a kind-essential set of properties. To exemplify a human nature (and thus to be human) means that you exemplify the set of properties essential for being human. The same goes for any other nature: tree nature, rock nature, divine nature, and so on.
"Okay, so I am human because I exemplify the set of properties necessary to be human."
Correct, and the claim of Christian doctrine is that Jesus simultaneously exemplified two sets of kind essential properties or natures, that which is necessary to be human and that which is necessary to be divine.
"So what's the problem?"
The problem is that it is not the natures that exemplify their constitutive properties, rather it is Jesus. It is not the human nature that is ignorant but rather Jesus. It is not the divine nature that is omniscient but rather Jesus.
Thus it makes no sense to say that Jesus was ignorant qua his humanity but omniscient qua his divinity. You're still saying that Jesus was simultaneously ignorant and omniscient which is a contradiction.
"So where does Nestorianism come in?"
Because the only way to make sense of reduplicative predication is to assume tacitly that there really are two different agents in the incarnation - the Son of God and the man Jesus - such that each exemplifies one of the natures.
"So either reduplicative predication offers no response to the problem at all or it offers a response that leans toward a heresy?"