Christian theologians and philosophers have made use of qua predications to remove apparent contradictions in the Incarnation. To use Tim Pawl’s example, Christ is passible and Christ is impassible. The apparent contradiction is then supposed to be removed by saying:
Christ is passible qua human
Christ is impassible qua divine.
A very similar move is made by non-presentist endurantists in regard to changing properties. That Alice is sitting and that Alice is standing appear to be contradictory, but we can remove the contradiction by qualifying with a time:
Alice is sitting at t1
Alice is standing at t2.
Tim Pawl lists four interpretations of what the qua modifies in the Christological case, and there are also four parallel interpretations of what the at modifies in the time case (as Pawl himself has noted). I want to focus on two of the four:
Predicate: Christ is passible-qua-human and impassible-qua-divine.
Copula: Christ is-qua-human passible and is-_qua_divine impassible.
Similar points will apply to the time case.
I think there is something suspicious going on here. Start with the observation that there are languages that don’t use a separate word as a copula for predication. Indeed, this is even true of English when what we are predicating is an active verb. “Socrates talked”, “Socrates talks” and “Socrates will talk” have no separate words as copulas. It is tempting to say that this is a cheap shot. One may say that the linguistic effect of the copula in such cases is effected not by a separate word, but by the word order or some other syntactic feature, or else by the context.
Now continue to a second observation. In standard philosophical usage, “sitting” is not a predicate. The predicate is “is sitting”. If we were to add a copula to the predicate, we would have the non-sentence:
- Alice is is sitting.
A (unary) predicate is an incomplete expression, which generates a sentence when it is completed with a referring expression. The meaning of the resulting sentence is determined by the meaning of the predicate and the referring expression. In a Montague-style grammar, we will think of a predicate syntactically as a method of transforming referring expressions to sentence, and we will think of a predicate semantically as a function from meanings of referring expressions to meanings of sentences (i.e., to propositions). On this picture, in a simple subject-predicate sentence, there is no copula. There is a referring expression—“the subject”—and there is a predicate applied to it. The application of the predicate is not itself something that figures in the grammar beyond the predicate. The meanings of the predicate and of the subject are sufficient to determine the meaning of the sentence we get by applying the predicate to the subject.
In a Montague-style grammar, the predicate need not be a separate “piece”. For instance, we could have a language where by writing a referring expression in bold, we express the proposition that the subject referred to is bald. Thus, the predicate transforms the referring expression “Bob”, whose meaning is a simple rigid reference to Bob, to the sentence “Bob”, whose meaning is that Bob is bald. There is no copula, nor can there be, as the transformation from the referring expression to the sentence is entirely effected by the predicate. A subject-predicate sentence in standard compositional semantics has only two compositional ingredients: subject and the predicate.
If this is right, then the idea of modifying the copula with qua or of tensing the copula sounds badly confused. There is nothing like that in the sentence, compositionally speaking, to modify. One might as well talk of modifying the first “to” in “He desires to eat pie” (or even the “o”).
But maybe we can try to reconstruct what the people who talk of “modifying the copula” might be doing. They may be thinking—and quite possibly correctly so—that there is a finer structure than at of predicates. There may be something we can call a “pre-predicate”. Examples in English might be intransitive verbs in the infinitive or adjectives. Pre-predicates aren’t predicates. One can’t just apply them to a referring expression and get a sentence: they lack crucial determinations, such as of tense or respect. At this point, we have a choice between two ways to represent things that are likely equivalent. We can think of a copula semantically as a function from meanings of referring expressions and meanings of pre-predicates to meanings of sentences (with a corresponding syntactic transformation from referring expressions and pre-predicates to sentences). Or we can think of a copula as a function from meanings of pre-predicates to meanings of predicates (i.e., functions from meanings of referring expressions to meanings of sentences).
In any case, the additional structure afforded by pre-predicates and copulas captures the idea that there is something with a greater incompleteness than a predicate—something that doesn’t just apply directly to a referring expression to generate a sentence. And we can now straightfowardly distinguish modifying the pre-predicate versus modifying the copula.
The challenge of this approach, however, is to give an account of the meaning of a pre-predicate. I don’t know how to do that.
Disclaimers: I am not a linguist. I am not even a philosopher of language. The above is probably messed up in places that will make experts cringe.
No comments:
Post a Comment