"And the Word was made flesh, and dwelt among us . . . . (John 1:14)
Physicalism is popular among philosophers these days. So it is no surprise that Christian philosophers are drawn to it as well, including those who subscribe to the central teaching that God the Son, the second person of the Trinity, the Logos or Word, became man in Jesus of Nazareth.
Incarnation, whatever else it involves, involves embodiment. How is God the Son during his earthly tenure related to his body? Trenton Merricks assumes that "God the Son . . . is related to his body just as you and I are related to our respective bodies." ("The Word Made Flesh," 261.) One might have thought that the embodiment relation that connects the Son to his body would have to be very special or even sui generis; after all, the Logos is sui generis and so it might naturally be thought that any relation into which it enters would inherit that sui-generic quality. Merricks, however, assumes that divine and human cases of embodiment are cases of one and the same embodiment relation. The divine case is just a special case. Call this the Same Relation assumption. (My tag, not Merrick's).
And what relation is that? On physicalism, "You have a body if and only if you are identical with that body." (294) So the Same Relation assumption in conjunction with physicalism yields the conclusion that the Incarnate Son is "identical with the body of Jesus." (294) So in becoming human, the Incarnate Son "became [numerically identical to] a body."
This does not make much sense to me and I find it more worthy of rejection than of acceptance. My problems begin with physicalism itself.
Physicalism
The physicalism in question is not physicalism about everything, but about beings like us, minded organisms, if you will, which include all human animals. (If there are so-called 'abstract objects,' then they are not physical, and presumably before the Incarnation, no member of the Trinity was a physical object.) Physicalism is "the claim that each of us is a physical object." (294). Now there is a sense in which it is obviously true that each of us is a physical object, and that is the sense in which it is obviously true that each of us has a body; but one quits the precincts of the obvious and the datanic and enters the space of philosophical theories when one claims that one has a body by being numerically identical to a body, or that the the 'is' in 'Each of us is a body' is the 'is' of identity.
For this is not obvious. How do you know that the 'is' in 'Each of us is a body' is not the 'is' of composition? (Compare: 'Each of these statues is bronze.' That can't mean that each of the statues is identical to bronze or to a particular hunk of bronze. A statue and its proximate matter have different persistence conditions both temporally and modally.)
But we are discussing physicalism. I am not asserting that we are composite beings. And I am not espousing substance dualism either. I am merely considering whether physicalism about minded organisms is an intellectually satisfying position. Does it command our assent? Merricks thinks it is "pretty obvious" that physicalism is true. (294) I don't find it obvious at all. And as Hilary Putnam once quipped, "It ain't obvious what's obvious."
On physicalism, I am identical to the living, breathing, sweating animal wearing my clothes. Of course, I am not always sweating and not always wearing clothes; but if I cease breathing, I cease living and, on physicalism, I cease existing. (The physicalist claim is obviously not that I am identical to a corpse or an inanimate hunk of human-looking flesh and bones wearing my clothes.) To underscore the obvious, when I speak of identity I mean numerical identity.
One might find physicalism hard to swallow. If x and y are identical, then whatever is true of x is true of y and vice versa. That is necessarily so, and part of what we mean by 'identity.' But it is true of me that I am a "spectator of all time and existence," (Plato, Republic VI) whereas that is not true of my body. So I can't be identical to my living body. To take a less grand example, I am now thinking of a girl I used to know. So is my body thinking of her? The whole body? Some proper part or parts thereof? Presumably not the plantar fascia in my left foot. My brain? The whole brain? Some proper part thereof? How could any portion of the brain be the subject of acts of thinking? That doesn't make much sense. In fact, it does not make any sense. A bit of highly organized meat is the subject of acts of thinking in the broad Cartesian sense of 'thinking' which includes memorial acts? Are you serious?
Could it nonetheless be true that what thinks in me when I think is the brain or some portion thereof? I suppose, but then it would be a mystery how it is true. The Incarnation may be a mystery, but if we are trying to understand the Incarnation physicalistically, then physicalism had better not be a mystery too. I'll come back to this point below.
The obviousness of physicalism seems to have vanished. Merrick does not give the following invalid argument, but what he says on 294 ff. suggests it:
Whatever has physical properties is a physical object.
Socrates has physical properties.
Therefore
Socrates is a physical object.
Therefore
Physicalism is true.
The argument is rendered invalid by an equivocation on 'is' as between the 'is' of class inclusion and the 'is' of identity.
What I have said does not refute physicalism, but it does show that physicalism is far from obvious and does not follow from such Moorean facts as that you and I have shape and mass. So I balk at Merricks' "it seems pretty obvious that physicalism . . . is true." (294) It is not obvious at all.
Property Dualism
Can these objections be met by adopting property dualism? Merricks' view is that while we are physical objects having physical properties, we are not merely physical objects: we also have mental properties. "Persons also have mental properties." (295) Furthermore, these mental properties are irreducible to physical properties. Merricks tells us that his physicalism is consistent with property dualism. (295) I think it is fair to say that with respect to beings like us, he is a substance monist and a property dualist.
The idea is that the human individual having properties is a physical object, but that it has two different mutually irreducible sorts of properties, physical properties and mental properties. But how does this help? I am thinking about a girl I used to know, a particular girl, Darci. Is there a mental property corresponding to the predicate '___ is thinking about Darci'? I doubt it, for reasons I don't have the space to go into, but suppose there is this strange property. Call it 'D.' Presumably it is an abstract object unfit to do any thinking. So it is not the subject of the thinking, that in me which thinks when I think.
Should we say that I am thinking about Darci in virtue of my instantiating of D? But who am I? On physicalism, I am identically this living body. So this animal body instantiates the mental property. But this brings us right back to our earlier question as to which part of the animal body does the thinking. Introducing a dualism of properties does not answer this question.
How Could a Non-Physical Object Become a Physical Object?
But even if physicalism is true, how could it, in tandem with the Same Relation assumption mentioned above, be used to make sense of the Incarnation, or rather the embodiment the Incarnation implies? How could the second person of the Trinity, a purely spiritual, nonphysical person, at a certain point in history become numerically identical to the body of Jesus? How could an immaterial being become a material being? I should think that an item's categorial status is essential to it. So if an abstract object such as the number 7 or the set of primes is nonphysical, then this object is nonphysical in all possible worlds in which it exists, and indeed in all possible worlds, full stop, given that 7 and the number of primes are necessary beings. If so, then in no possible world could the number 7 or the set of primes become a concrete item sporting causal properties and spatiotemporal locations.
Something similar holds for that necessary being which is the second person of the Trinity. Its purely spiritual, wholly nonphysical nature is essential to it. So, on the face of it, its embodiment in a particular human being cannot be understood as its becoming numerically identical to that human being. For then, per impossibile, it would have to quit its kind and become another kind of thing.
Rejecting Kind-Essentialism
Now the above is an obvious and obviously powerful objection to which Merricks makes a daring response. He recommends rejecting the kind-essentialism that is at the back of it:
Believers in the Incarnation must reject kind-essentialism. Once kind-essentialism is rejected, it is hard to see why the non-physical God the Son could not become [numerically identical to] a human organism. Perhaps this is the sort of thing that might not seem possible merely upon reflection, given no relevant revelation. But the same thing goes for God the Son's becoming human. This is the mystery. (296)
I don't follow the reasoning here. Let us assume that we accept as revealed truth that God became man in Jesus of Nazareth. And let us assume that the Incarnation is, as Merricks says, a mystery. Now faith seeks understanding. Fides quarens intellectum. In this case we want to understand how God became man. How is understanding helped by the rejection of what appears to the unaided intellect as obviously true, namely, kind-essentialism? Is its falsity supposed to be a mystery too?
If I want to understand the Incarnation, I have to use principles that to the unaided discursive intellect appear secure. If I use the Incarnation to reject kind-essentialism, which is one of the principles that appear secure to the finite intellect, then I haven't made sense of the Incarnation; I have wreaked havoc on the discursive intellect. Would it not be better simply to rest with the Incarnation as mystery and forgo desperate attempts to make sense of it that violate very secure principles that are arguably definitive of finite understanding?
Why Not Reject the 'Same Relation' Assumption?
Suppose one wants to retain one's physicalism about humans at all costs and to accept the Incarnation as well. Would it not be better to jettison the 'same relation' assumption? Would it not be better to say that embodiment in the divine case is a different relation from embodiment in (merely) human cases? Suppose that in the merely human cases, to have a body, i. e., to be embodied, is just to be a body, i.e., to be identical to a (living) body, while in the divine case to have a body is something else, something perhaps incomprehensible to us in our present state. One could then be a physicalist without rejecting kind-essentialism.
Note that Merricks is not a physicalist about God or any of the persons of the Trinity prior to the Incarnation. He does not hold that every mind is physical. He makes an exception for the divine mind. Well, then he can make an exception in the way a divine mind becomes embodied should such a mind become embodied.
There seems to be two ways to go for one who aims to accept the Incarnation while also accepting physicalism about minded organisms. Accept either package A or package B:
Package A
Incarnation; physicalism; 'same relation' assumption; rejection of kind-essentialism.
Package B
Incarnation; physicalism; 'different embodiment relation' assumption; acceptance of kind-essentialism.
I should think that Package B is the more attractive of the two.
Merricks' paper is here. Many thanks to Professor Andrew M. Bailey for uploading it! Ditto to Kevin Wong for drawing my attention to it and for supplying me with a bibliography of recent work on physicalist Christology. Mr. Wong is a gentleman and a scholar!