"Epistemic Modals and Conditionals Revisited",
a colloquium presentation by Kai von Fintel (MIT).

Abstract

In this talk, I will compare two nonstandard approaches to the formal
semantics of epistemic modals and indicative conditionals. The talk has
the following structure:

I. The Problem

1. As a reminder, I will sketch the epistemic analysis of indicative
conditionals, suggested by Kratzer (1986) as the proper response to the
contextdependency problem uncovered by Gibbard (1981).

2. Many philosophers (Adams, Gibbard, Stalnaker, Edgington, et.al.) have
responded to the Gibbard problem (and some other facts, which I will not
explore in detail) with the doctrine that indicative conditionals have no
truth conditions, do not have propositions as their semantic values. The
main reason they reject a Kratzer-style analysis is that indicative
conditionals do not appear to be treated in discourse (questioning,
agreeing, denying, etc.) as reports on the speakers state of knowledge
(see Bennett 2003 for an explicit argument of this nature). The
consequences of the no-truth-conditions doctrine for a systematic natural
language semantics, however, are disturbing.

3. At the same time, and quite independently, many linguists say that
epistemic modals (and evidential markers) combine with a sentence to
convey the speakers attitude (confidence, evidence) towards the
proposition expressed by the sentence, rather than directly contributing
to the proposition expressed. Again, it is unclear how this idea should
fit into a formal semantics.

II. Layered Meanings?

1. Recently, in work very familiar to the UMass audience (in particular by
Kaplan, Kratzer, and Potts), there has been much progress in formal
research on an extrapropositional (expressive rather than assertive) layer
of meaning. I explore the outlook for utilizing this work, together with
insights from Fallers work on evidentials in Quechua (Faller 2002), to
sketch a formal reconstruction of the traditional epistemic modal =
comment view.

2. Once we have such an analysis in place, we can pursue the idea that in
indicative conditionals, the 'if'-clause is restricting (in Kratzer's
sense) an extrapropositional epistemic operator. We will explore whether
this picture can make sense of the behavior of epistemic modals and
indicative conditionals in natural language. One crucial point is that the
speech acts that are performed with sentences that have complex layered
meanings are predicted to be more variegated that in a simple assertion
model of discourse.

III. Relative Truth?

1. In very recent work by MacFarlane (2003) and Egan et al. (2003), a
puzzle about the properties of epistemically modalized sentences in
discourse has given rise to a different analysis of epistemic modality.
This analysis relies on a new kind of indexical ("assessment relative")
semantics. I will explicate the analysis (drawing also on Papafragou 2003)
and compare it to the layered semantics sketched in the previous section.
I will also look at connections to the dynamic analysis of epistemic
modals and conditionals first proposed by Veltman and recently fleshed out
by Gillies (2003).

2. I will then consider whether the assessment-relative semantics can be
carried over to the case of indicative conditionals. Note: This is rich
and complex terrain. The talk will have to skim over a lot of the
details. I hope to be able to share with you at least a rough draft of the
paper before the talk.

Bibliography

BENNETT, Jonathan: 2003. A Philosophical Guide to Conditionals. Oxford
University Press.
EGAN, Andy, HAWTHORNE, John, & WEATHERSON, Brian: 2003. Epistemic Modals
in Context. URL http://www.brown.edu/Departments/Philosophy/homepages/
weatherson/em.pdf.
FALLER, Martina: 2002. Semantics and Pragmatics of Evidentials in Cuzco
Quechua. Ph.D. thesis, Stanford. URL
http://www.mpi.nl/world/persons/profession/marfal.html.
GIBBARD, Alan: 1981. Two Recent Theories of Conditionals. In William
Harper, Robert Stalnaker, & Glenn Pearce (Editors) Ifs: Conditionals,
Belief, Decision, Chance, and Time, pages 211247. Dordrecht: Reidel.
GILLIES, Anthony S.: 2003. Epistemic Conditionals and Conditional
Epistemics. URL http://www.people.fas.harvard.edu/~gillies/epist_cond.pdf.
Accepted for publication in Nous.
KRATZER, Angelika: 1986. Conditionals. Chicago Linguistics Society, 22(2):
115.
MACFARLANE, John: 2003. Epistemic Modalities and Relative Truth. URL http:
//socrates.berkeley.edu/~jmacf/epistmod.pdf.
PAPAFRAGOU, Anna: 2003. EpistemicModality and Truth Conditions. URL
http://www.cis.upenn.edu/~anna4/papers/epmodtruth.pdf. To appear in A. Klinge &
H. Muller (eds.), Perspectives on Modality (provisional title). Amsterdam:
Benjamins.