I have been spending some time working through the doctrine of the Incarnation and as such have been spending a great deal of time in Tom Morris's The Logic of God Incarnate. There are a number of questions that I plan to post on beginning with this post about reduplicative statements and Morris's two minds view.
I think most people who have brushed up against the doctrine of the Incarnation have probably heard some form of the reduplicative move. Reduplicative statements are supposed to block contradictions by showing that the Incarnate God held contradictory properties qua his two natures. These statements take the form of 'x qua A is N' or 'x as A is N.' Morris seems, rightly I think, to want to reject the reduplicative move because it is vulnerable to the rather serious objection that reduplicative statements result in saying that a subject holds a property and its logical compliment. The objection is that if we consider a conjunctive reduplicative proposition of the form 'x as A is N and x as B is not N' then the result is that x is both N and not N.
"If the subjects of the conjuncts are the same and the substituends of N are univocal across the conjunction, then as long as the reduplication predicates being A of x and predicates being B of x, and being N is entailed by being A, and not being N is entailed by being B, then the reduplicative form of predication accomplishes nothing except for muddying the waters, since in the end the contradiction stands of x being characterized as both N and not N." (TLGI 48,49)
So reduplicative statements such as, "Jesus Christ qua his divine nature never came into existence, but Jesus Christ qua his human nature did come into existence" would entail the one person, Jesus Christ, both did and did not come into existence. I think Morris is right about muddying the waters, and I don't see how reduplicative statements can free orthodox Christology from the charge of contradiction.
Morris does a nice bit of work arguing that we should consider natures as natural kinds. In which case it might not be impossible for something to belong to more than one natural kind. This account of natural kinds seems to be a good answer to the two natures problem that avoids the reduplicative move. However, when Morris gets to the two minds portion of his defense he brings the reduplication move back into the argument. Morris states that God qua his divine mind cannot be tempted, but God qua his human mind can be tempted. If the reduplicative objection holds then it results in God being both temptable and not temptable. We might also add that the statement could be formed such that God is both omniscient and not omniscient. If this is the case then Morris's defense fails to rescue the doctrine of the Incarnation form the logical incoherence charge.
"The objection is that if we consider a conjunctive reduplicative proposition of the form 'x as A is N and x as B is not N' then the result is that x is both N and not N."
Matthew, whenever I see this sort of objection, my response is always, "Yes, it would be -- if you didn't reduplicate." The error of it seems (as far as I can tell) to be in thinking that the 'as A' or 'as B' doesn't belong to the predicate. In English you can put it in all sorts of places in the sentence; but it always qualifies the predicate applies to the subject. Thus the real result you get is that X is N in being A; and it is not N in being B. This is no more troublesome than any other way in which N and not-N apply to X but don't violate the principle of noncontradiction because they apply to it 'in different respects'. In fact, that's the whole point of the reduplicative move.
I haven't read Morris on the natural kinds argument; to me it sounds like a more promising way to go, because it deals with something the reduplication move doesn't cover (because it's something it presupposes).
i don't think that works. Reform in the propositional calculus:
A
B
(X→A)→(X→N)
(X→B)→(X→-N)
therefore
N & -N
I am tempted to adapt an old argument: such a God would be subject to the laws of logic, but we can at least imagine a God that wasn't, so the God that is can't be the True God! Now, let
A = a God who in His infinte wisdom has revealed Himself to human beings, by incarnation or otherwise
B = a God who in His infinite mercy has hidden His face from us
both of which (I think) I could find Biblical quotes for, if I could be bothered to...
N = worshipability
I don't think your reformulation is accurate, because reduplicative phrases, as I noted, qualify the application of the predicate to the subject; and the reformulation doesn't capture this at all. A reduplicative phrase essentially says that P applies to s in this way or sense; and no direct contradiction can be drawn from saying "Both N (in X sense) and not-N (in Y sense)."
The reduplicative approach does work, provided that the object of our discussion can be separated into different parts. For example, someone could cut off part of a tree and make it into a book. Then the same tree "as a living organism" does not present words to a reader, while "as a book" it does. Because of the qualifier, the tree cannot simply be "X" in every part of an argument in symbolic form. It should be "L" for "the tree as living organism" and "B" for "the tree as book."
The really tricky part about using reduplication is positing parts in Christ: can God have one part which is tempted and experiences pain, but not another? Aquinas argues that Christ simply attaches (is unified with) one instance of human nature, so that that human mind and body become part of Christ, but at the same time Christ as God is perfectly simple and infinite. This seems to me the more interesting question.
Thankyou for that, M K Siebert. I am not at all sure that a "reduplicative predicate" is a helpful tool. What Aquinas is pointing to, surely, is the essentially mysterious nature of spiritual experience of which any complete account, considered purely logically, necessarily contains a contradiction. (In other words, the Incarnation is a member of a class. Philosophically, this is surely more comfortable than having to deal with as sui generis)
I would agree with the parthood comment, if we allow a very broad sense of the word 'part'. It's worth pointing out, though, that the second paragraph ultimately just boils down to whether there is a contradiction in saying "Christ is both God and Man" in the Chalcedonian sense of having two natures, one divine and one human. This is certainly presupposed by the reduplicative approach, and is, I agree, the more interesting question.
Innocent Abroad, I'm not sure I understand your comment about a complete account containing a contradiction if considered purely logically; if I understand this correctly, it certainly wouldn't be Aquinas's view.
My apologies for taking this long in responding. I think the point still stands that Morris has simply moved the location where orthodox Christians make reduplicative moves. Both MK Siebert and Brandon are on the right track that the reduplicative move requires a part/whole explanation. Stump and Leftow have done some recent work in this area that is informed by Aquinas, which I plan to comment on in another post. Tom Senor has a forthcoming paper that I think seriously calls into question Stump and Leftow's account for both philosophical and theological reasons. Most of what I have to say against part/whole accounts is due to having seen an early draft of this paper. Of course any errors in my part/whole rebuttal are qua my failed understanding, and anything I get right is qua Tom Senor's right thinking!
Here is a preview of part of the problem as I see it. If the attributes of the parts are rendered to the whole then the reduplicative move suffers from contradiction. However, if the attributes of the parts are restricted to the parts is what sense can the whole be said to have them. If the part Jesus Christ the man is non-omniscient, and the part God the Son is omniscient, then Jesus Christ ≠ God the Son.
MK Siebert-
I think you'll want a part/whole analogy that includes taking on a part, not losing one. Most people's intuition in your tree/book case is probably going to be that the book isn't a part of the tree at all. The kind of case you might want is something like a tree adding a new branch, where the branch is a new part. Of course this clearly isn't very much like the Incarnation part/whole relationship wherein a divine being is taking on a part that is in many respects not like the divine being at all. The Incarnation part/whole relationship might be more similar to tying a swing onto the tree. But does the swing part become part of the tree? I think most of us would think not. I think you are right that this is the more interesting question.
Hi, Matthew,
I look forward to your future post. I do think that the sense of 'parts' we need to consider is a very broad sense of the term - in the sense that, for instance, temporal parts are parts, or logical parts are parts. Parthood broadly considered, in other words. And this would force us to look more closely at the metaphysics of the sorts of parts that would be involved in the reduplicative strategy. And it sounds like the problem you are suggesting has to do with that. So, again, I look forward to it.