The Weekly Newsletter of MIT Linguistics

LFRG 3/8 - Matthew Mandelkern

Speaker: Matthew Mandelkern
Title: Bounded Modality
Date and time: Wednesday, March 8, 1-2pm
Location: 32-D461

To what degree does the meaning of an epistemic modal claim like ‘It might be raining’ resemble the meaning of an avowal of ignorance like ‘For all I know, it’s raining’? Progress on this question has been made by exploring differences in how constructions along these lines embed—-in particular by exploring their behavior as part of larger constructions like Wittgenstein (1953)’s ‘It might be raining and it’s not’ and Moore (1942)’s ‘It’s raining and I don’t know it’, respectively. A variety of approaches have been developed to account for those differences. All approaches, however, agree that the infelicity of unembedded Moore sentences and unembedded Wittgenstein sentences is to be explained in roughly the same way: such sentences are classically consistent, but commitment to both conjuncts is incoherent.

In this paper I argue against this consensus. If this consensus were right, then disjoined Moore sentences, and disjoined Wittgenstein sentences, would be felicitous. This prediction is borne out for disjoined Moore sentences, but not for Wittgenstein sentence. This creates a puzzle, since there is decisive reason to think that ‘Might p’ is consistent with ‘Not p’. I propose a new theory of epistemic modals and their interaction with embedding operators which predicts that, while ‘Might p’ is indeed consistent with ‘Not p’, when evaluating their conjunction, ‘Might p and not p’, we are forced to do so relative to an accessibility relation which makes the conjunction false. I show that this theory accounts not only for Wittgenstein sentences and their disjunctions, but also for the subtle behavior of embedded modals across the board. The upshot is that there is much in common between ‘For all we know, p’ and the meaning of ‘Might p’—-and thus much that is correct in the standard semantics for the latter—-but also a crucial difference: interpretation of the latter, but not the former, depends in a striking way on the intersentential dynamics of information.