Online Papers - Brian Weatherson

Epistemic Modals in Context 288
The correct norm is that one should only say something that’s true when evaluated
in the context you are in. We assume here that contexts can include more than
just the speaker. If Vinny the Vulture is speaking to a group of humans he arguably
cannot say Rotting flesh tastes great. The reason is that rotting flesh does not taste
great to the group of speakers in the conversation, most of whom are humans. This
norm gives us the nice result that Myles’s statement is appropriate, as is Moriarty’s,
even though in each case their most prominent audience member knows they speak
falsely. 34
This helps explain, we think, the somewhat ambivalent attitude we have towards
speakers who express epistemic modals that are false relative to our context, but true
relative to their own. What the speaker said wasn’t true, so we don’t want to endorse
what they said. Still, there’s still a distinction between such a speaker and someone
who says that the sky is green or that grass is blue. That speaker would violate the
properly relativised version of the only say true things rule, and Myles and Moriarty
do not violate that rule.
As MacFarlane notes, relativist theories deny ABSOLUTENESS OF UTTERANCE
TRUTH, the claim that if an utterance is true relative to one context of evaluation it
is true relative to all of them. It is uncontroversial of course that the truth value of an
utterance type can be contextually variable, the interesting claim that relativists make
is that the truth value of utterance tokens can also be different relative to different
contexts. So they must deny one or more premises in any argument for ABSOLUTE-
NESS OF UTTERANCE TRUTH, such as this one.
1. ABSOLUTENESS OF PROPOSITIONAL CONTENT: If an utterance expresses
the proposition p relative to some context of evaluation, then it expresses that
proposition relative to all contexts of evaluation.
2. ABSOLUTENESS OF PROPOSITIONAL TRUTH VALUE: If a proposition p is
true relative to one context in a world it is true relative to all contexts in that
world; therefore,
3. ABSOLUTENESS OF UTTERANCE TRUTH
This argument provides a nice way of classifying relativist theories. One relativist
approach is to say that Moriarty (or anyone else who utters an epistemic modal)
says something different relative to each context of evaluation. Call this approach
content relativism. Another approach is to say that there is a single proposition that
he expresses with respect to every context, but the truth value of that proposition
is contextually variable. Call this approach truth relativism. (So that the meaning
of ‘proposition’ is sufficiently understood here, let us stipulate that we understand
propositions to be the things that are believed and asserted and thus, relatedly, the
semantic values of ‘that’-clauses.)
It might look like some of our behaviour is directly inconsistent with any sort of
relativism. Consider the following dialogue.
34 Can we even say that someone speaks falsely here now that truth and falsity is always relative to a
context of evaluation? It turns out we can, indeed we must, although the matter is a little delicate. We
return to this point below.