PH130 Meaning & Communication
Extra notes for Lecture 2
Time was running out towards the end of lecture 2, so I thought a summary of the
main ideas of that lecture might be a good idea.
Summarising the idea of a theory of meaning…….
We treat ‘meaning’ functionally’.
So, the meaning of a sentence is whatever it is you know that enables you to grasp
the proposition expressed by an utterance of the sentence. The meaning of a word
is whatever it is you know that contributes to you being able to grasp the proposition
expressed by utterances of sentences in which the word figures. Intuitive idea here
is that meaning is compositional. The meaning of sentences is composed out of the
meanings of words plus the rules for composition. Where composition deploys
further connective words – things like ‘or’, ‘and’, ‘if…then__’, the meaning of such
words is, once again, whatever it is you know that contributes to you being able to
grasp the proposition expressed by utterances of sentences in which the word
figures. In the case of the propositional calculus connectives, what you know is the
truth-tables for the connectives.
Now, a proposition is what is expressed by an utterance of a sentence; it is what gets
to be either true or false. Davidson’s key insight is that knowing the meaning of a
sentence is knowing what proposition it expresses and that amounts to knowing what
it is for an utterance of a sentence to be true. It is knowing the truth conditions of the
sentence. That is why we don’t need to mention meaning or use words synonymous
with ‘meaning’ in giving an account of what you know when you grasp what
proposition is expressed by an utterance of a sentence. If for any given sentence ‘S’,
you know enough to be able to derive knowledge of,
(W) ‘S’ is true if and only if S
then you have knowledge that enables you to derive knowledge of the truth
conditions for ‘S’. Knowing the truth conditions just is knowing the meaning.
Two big points about this: (a) knowing instances of (W) is not trivial; (b) the claim is
that your knowledge of instances of (W) is derived from your knowledge of other
things that exploits the compositional structure of language.
On (a) first. Note, in (W) the sentence ‘S’ is mentioned on the left-had side and used
on the right-hand side. On the left of (W) we have a name for a sentence, for there
are quotation marks around the sentence. On the right-had side the sentence is
used to state the conditions under which the name sentence is true. So although, if
we give an instance of (W), e.g.
‘Jeremy Hunt remains in office’ is true if and only if Jeremy Hunt
remains in office
you might think it looks trivial; it is not. Compare the following instance of (W)
‘Yr mae’r ddraig goch’ is true if and only if Yr mae’r ddraig goch.
That is not trivial and it doesn’t even look trivial unless you’re a Welsh speaker. If
you are not, then you do not know this. And, critically, you do not know this precisely
because you don’t understand Welsh. What distinguishes a competent Welsh
speaker from you? Exactly the thing that Davidson claims. They know the above,
you don’t. So, knowing things like the above is knowing the sort of thing that gives
you grasp of the proposition expressed by utterances of the sentence ‘Yr mae’r
ddraig goch’.
On (b). This sets up a program for a systematic theory of meaning. You understand
a natural language like English in virtue of knowing a load of stuff. For each
sentence of English you know what proposition utterances of that sentence
expresses. The compositionality of the program is key to making sense of this.
Without compositionality, what you know for each sentence would be discrete,
separate from your knowledge of other sentences. But linguistic understanding is not
like that. It is systematic and productive. The value of a program for a compositional
theory of meaning is that it provides revealing granularity to what you know. You
know loads of stuff.
For example, for predicates of the language you know things like,
(1) The extension of ‘tall’ is the set of things that are tall
For names you know things like,
(2) ‘Jeremy Hunt’ stands for Jeremy Hunt
You might be tempted to think that knowing such things is trivial. You might think
that, putting it schematically, knowing for names all instances of the schema
(3) ‘a’ stands for a
is trivial. We spent some time discussing this. I claimed it was far from trivial.
Indeed, for instances using fictional names it’s false. Knowing instances of the
schema (3) is only possible if the object a exists. Knowing that ‘Jeremy Hunt’ stands
for Jeremy Hunt is to know that the name (sound/inscription) stands for a particular
real object. Having that knowledge is only possible if the object exists.
What’s the advantage of this idea of a theory of meaning? Suppose you know things
like (1) and (2) plus the relevant things about the rules of composition. Keep it
simple for now and consider only the rules of composition for the propositional
connectives, say negation and disjunction. Suppose you know the truth tables for
those two and (1) and (2). We have now supposed you know enough to be able to
understand an infinite number of propositions, those expressed by sentences
compiled out of the name ‘Jeremy Hunt’, the predicate ‘…is tall’ and the sentential
connectives ‘or’ and ‘not’. We can show how you know instances of (W) for an
infinite range of sentences like,
Jeremy Hunt is tall
Jeremy Hunt is not tall
Jeremy Hunt is tall or Jeremy is tall
Jeremy Hunt is tall or Jeremy Hunt is not tall
It is not the case that (Jeremy Hunt is tall or Jeremy Hunt is not tall)
……..and so on.
Okay, those are some pretty boring sentences. But you get the idea. Positing the
relevant knowledge of the structural components of the language (stuff like (1) and
(2)) we can explain the systematicity and productivity of linguistic understanding.
Thus far, there is no other explanation around for the systematicity and productivity
of linguistic understanding. The program is not uncontentious, precisely because it is
not trivial. But there is nothing else like it that comes close to making sense of how
linguistic communication in all its systematicity and productivity is possible.
ML
27 April 2012.