Willard Van Orman Quine

Quine on Reference and Ontology 135
Here, in the gap between the significance of the sentence and the significance
of its parts, Quine sees empirical slack, which is manifest
in ontological relativity.
We have already seen a clear example of the gap between the significance
of the whole sentence and the significance of its constituent
parts. In the case of observation sentences, we saw that, taken as
wholes, they get their meaning simply from their relation to sensory
stimulation. If we think of them in that way, as responses to stimulation,
we have no reason to view them as making any ontological
claims. It becomes possible to see them as making such claims only
when we take them to be part of a more sophisticated theory, which
includes the notion of identity, plurals, and so on. To repeat the point
of §I, the relation between language and the world by which our language
comes to have empirical meaning and empirical content is not
a relation between names and objects but rather a relation between
sentences and sensory stimulations.
This idea is fundamental for all of Quine’s views about language,
and it underlies ontological relativity. For the idea applies not only
to observation sentences but also to all sentences – to language as a
whole. It is most clearly seen in the case of an observation sentence.
One’s propensity to accept or reject such a sentence depends only on
one’s current sensory stimulations. Other sentences are responsive
not only to current stimulations but also to the other beliefs that
one has. If two scientists, say, agree about what they are now seeing
but disagree about whether it is evidence for a given claim, this will
surely be because of some other disagreements. The claim is thus
answerable not only to what they are then observing but also to
the other things about which they disagree. The empirical meaning
of such a sentence is not exhausted by its links to stimulations;
it also consists of its links to other sentences. These sentence-tosentence
links, and the dependencies of meaning they set up, are far
too complex and many-sided for us be able to reconstruct them in
detail.
Let us quote a passage from Word and Object on this point. Quine
is considering the inference that a chemist may make from seeing a
greenish tint in a test tube to thinking that the substance contains
copper. Such an inference – from the observation sentence ‘It’s greenish’,
let’s say, to ‘There was copper in it’ – obviously draws on the
general background knowledge that our chemist possesses. Quine
Cambridge Companions Online © Cambridge University Press, 2006