Online Papers - Brian Weatherson

Epistemic Modals in Context 290
just overheard, it would be perfectly natural—and pretty clearly correct, so long as
nothing funny is going on behind the scenes—for Watson to assert (47). A view that
tells us that Watson’s saying something crazy relative to everybody who’s likely to be
a member of his audience is in pretty serious conflict with our pretheoretical judgements
about the case. (Enlarging the context to include both Holmes and Watson
obviously doesn’t help, either.)
The second problem concerns the social function of assertion. In particular, it
causes difficulties for an attractive part of the Stalnakerian story about assertion,
that the central role of an assertion is to add the proposition asserted to the stock
of conversational presuppositions (Stalnaker, 1978). On the content relativist view,
it can’t be that the essential effect of assertion is to add the proposition asserted to
the stock of common presuppositions, because there’s no such thing as the proposition
asserted. There will be a different proposition asserted relative to each audience
member. That’s not part of an attractive theory. And it’s not terribly clear what
the replacement story about the essential effect of assertion—about the fundamental
role of assertion in communication—is going to be. It may be that there’s a story to
be told about assertability—about when Moriarty is entitled to assert, for example,
“it might be that Holmes is in Paris”—but there’s no obvious story about what he’s
up to when he’s making that assertion—about what the assertion is supposed to accomplish.
(And if you think that appropriateness of assertion’s got to be tied up with
what your assertion’s supposed to accomplish, then you’ll be sceptical about even the
first part.)
The third problem concerns epistemic modals in the scope of temporal modifiers.
The content relativist has difficulties explaining what’s going on with sentences like
(48).
(48) The Trojans were hesitant in attacking because Achilles might have been with
the Greek army.
On the content relativist view, (48) will be false relative to pretty much everybody—
certainly relative to everybody alive today. It’s certainly false that the Trojans were
hesitant because, as far as we know, Achilles was with the Greek army. (Or worse,
because, as far as we knew then, Achilles was with the Greek army.) But, depending
on how the Trojan war went, (48) could be true relative to everybody. 37
Finally, content relativism has a problem with commands. Keith’s Mom says:
(49) For all days d, you should carry an umbrella on d if and only if it might rain
on d.
37 We don’t take any stand here on just how the war went, if it happened at all. The important point is
that whether (48) is true when said of a particular battle is a wide-open empirical question, not one that
can be settled by appeal to the semantics of might. The content relativist says, falsely, that it can be thus
settled.