Willard Van Orman Quine

138 peter hylton
scientific enterprise. They are related by structure, and objects figure as
mere nodes of the structure. What particular objects there may be is indifferent
to the truth of observation sentences, indifferent to the support they
lend to theoretical sentences, indifferent to the success of the theory in its
predictions. (PTb 31)
Objects, along with reference to objects, are central to our theory of
the world, for we cannot get by without analyzing our sentences so
as to reveal structure: Otherwise we could never master the sentenceto-sentence
links that are essential to language beyond the observational
level. For all that, however, the role of objects is secondary;
the truth of sentences and their links to one another are primary.
Hence the idea that we could analyze sentences in more than one
way while leaving untouched both their truth-values and all the infinitely
complex links among them.
So far we have spoken of this idea as no more than an abstract
possibility. Quine, however, is in no doubt at all that there are such
alternative methods of analysis. He says, indeed, that the matter “admits
of trivial proof” (RJW 728). There are in fact a number of ways in
which Quine thinks the point can be demonstrated. Perhaps the simplest,
and certainly the one to which he most often appeals in recent
writings, employs the idea of a proxy function. The idea here is that
we take any one-to-one function f defined over the objects to which
our beliefs apparently commit us. (An example for spatiotemporal
objects, trivial but no worse for that, is spatiotemporal complement
of. This function maps any given object onto the rest of space-time,
i.e., to all of space-time excluding the given object.) Now we reinterpret
each sentence that appears to be about an object x as being
instead about f(x). And we also reconstrue each predicate so that it
holds of f(x) (the spatiotemporal complement of x, in our example)
just in case the original predicate held of x.
In one sense the reconstruals – of objects and of predicates – cancel
out, in trivial fashion, to leave the sentence unaffected. A reconstrued
sentence will be true under any particular circumstances just in case
the original version was also true under the same circumstances.
Since truth-values are unchanged, so also are inferential relations
among sentences and all of the sentence-to-sentence connections.
So at the level of sentences and truth, it seems as if talking in the
proxy-function language instead of our own would simply make no
difference at all; hence it might seem as if these are not two separate
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