Summer / Winter School 2022
26 July 2022
One line of thought in contemporary philosophy has tried to study meaning by thinking about belief reports.
This is an introduction to that line of thought.
Propositions are things that we believe, doubt, say, deny etc.
All of the following are intelligible:
Alex believes that Conrad is an author.
Chris doubts it (i.e. that Conrad is an author).
Alex believes something that Chris doubts (i.e. that Conrad is an author).
What Alex believes is true.
What Alex believes might have been false.
If we take those claims at face value, there are things that people believe and doubt.
There are also things that are true, but not necessarily.
Sentences stand in relations to propositions which are the contents of those sentences: a sentence is true if and only if its content is.
We can ask questions about propositions, including questions about how many of them there are, and how they are related to sentences.
One of these questions is about how ‘fine-grained’ propositions are: how many different sentences have the same proposition as their content?
Conrad is an author.
Korzeniowski is an author.
en.wikipedia.org/wiki/Joseph_Conrad
It is natural to think that (1) and (2) have the same content.
A belief report is a sentence of the form \(\text{\textit{A} believes that \textit{S}}\).
Alex believes that Conrad is an author.
Alex believes that Korzeniowski is an author.
It is easy to imagine a situation where it seems that (3) is true, but (4) is false.
A belief report is true if and only if the subject of the report believes the proposition that is the content of the sentence in the ‘that’-clause of the report.
So, (3) is true if and only if Alex believes the content of (1).
If (1) and (2) have the same content, then (3) and (4) have the same content.
If (3) and (4) have the same content, then, necessarily, they are either both true or both false.
It is possible that (3) is true but (4) is false.
So, (1) and (2) do not have the same content.
Accept the conclusion.
Reject the simple theory of belief reports, and then reject premise 1.
Reject premise 3, and accept that our judgements about the truth of sentences can be deeply misleading.
It is natural to think of the content of a sentence as its meaning, at least in one sense of ‘meaning’.
If we accept the first response to the substitution argument, then we have an argument for the conclusion that (1) and (2) have different meanings.
The meaning of a sentence depends on the meanings of the words in it.
(This is generally taken as a fundamental principle about language.)
So, if (1) and (2) have different meanings, then ‘Conrad’ and ‘Korzeniowski’ have different meanings.
At this point there is a puzzle, because we seem to have an argument for the claim that two names for the same object can have different meanings.
This is in tension with the natural thought that the meaning of a name just is the object that the name denotes.
Or, we could reject the substitution argument, which requires either rejecting the simple theory of belief, or accepting that our judgements can be deeply misleading.
German: Frege (1892)
English: Frege (1948)
King, Soames, and Speaks (2014)
Saul (2007)