My Jottings on Reduplication have caused some perplexity, so I thought a clarificatory post was in order. So here's my thought on the general 'lay of the land' when it comes to reduplication.
First, it needs to be understood that the original context of 'the reduplicative strategy' really isn't the question of whether the Incarnation as understood by Chalcedon is contradictory. On the contrary, reduplicative phrasing is something that comes very naturally to anyone who comes from a background based on the Chalcedonian Definition and the Tome of Leo. Its primary purpose is simply to avoid sounding like an Arian, Nestorian, or Monophysite in various contexts. (Aquinas, for instance, is often associated with 'the reduplicative strategy', but he doesn't, so far as I know, use it to deal with accusations of contradiction. On the contrary, he is simply interested in it for itself, because of its value for clarifying Christological language. It makes it easier to talk about the sense in which Christ is subject to the Father, and the sense in which He is not, for instance.)
Is the reduplicative strategy relevant in allegations of contradictions in traditional Christology? Absolutely, because the natural reply to any such allegation is reduplicative. If someone says, "There is a contradiction in your Christology because it requires that Christ be both mutable and immutable," it is an entirely reasonable reply to say, "The contradiction is only apparent; Christ is mutable as man and immutable as God." And so on with any other similar allegation.
Now, my Jottings were primarily concerned with pointing out that there is no structural flaw whatsoever with a reduplicative reply. It is a reasonable reply and not, as Morris claims, "a muddying of the waters"; it is not, as is sometimes claimed, simply a complicated way of stating the contradiction. First, because there are perfectly reasonable reduplications which are clearly not contradictory, e.g., "As father, Tom does not have a responsibility for the city, but as mayor he certainly does." Second, because on an explanatory account of reduplication it can be seen that reduplications like these are, in fact, claims that the predicates apply "in different respects." Any attempt to try to draw out a contradiction from the reduplication itself will simply fail, because reduplication itself blocks any such attempt.
Now, reduplication is not a Christology; it is one relatively minor element of any Christology of the Incarnation. And thus, it is entirely possible to deny that we can reduplicate in the case of Christ. This, however, is an entirely different argument; it is not an argument about reduplication itself but about one person possessing two natures, and what that would mean. It is not a contradiction drawn from the reduplication but an argument that reduplication is impossible. This, indeed, is required by reduplication itself, since one of the effects of reduplication is that it shows where the real issues lie. For example, if we say "Christ as man is mutable but as God is immutable," this shows that the real issue is not that Christ is both mutable or immutable, but the way in which we can talk about Christ's manhood being distinct from His Godhead.
My own view is that any position that allows that Christ is both God and man must necessarily allow some sort of reduplication (or claim that there is no distinction between being God and being man at all). If this is so, the real issue when people are talking about reduplication is not reduplication at all, but conciliar Christology itself.
