Presuppositions and Pronouns - Nijmegen Centre for Semantics

Modals 193
The discourse in (39) is awkward, and this has to do with the types of modality
that can and may allow for, and in particular with their presuppositional
requirements. As before, may in (39) can be read either epistemically or
deontically, which doesn't however make a relevant difference to its
presuppositional requirements. The modal can in (39), on the other hand, is
modal-
most likely to get an 'ability' interpretation: the first sentence in (39) prefers
a reading on which it states that Fred masters a certain skill. This ability
interpretation can be characterized as follows. Let the domain of can be a set
s of states that agree with the current state in that Fred has, say, the same
acrobatic skills that he has here and now; its co-domain is that extension s¢ s$
of s in which Fred balances a banana on the tip of his nose. What the first
sentence in (39) says, then, is that s$ s¢ is not empty.
Intuitively, there are two ways in which one might view the temporal
connection between the domain of an ability modal and the utterance time.
On the one hand, one might say that the temporal dimension is irrelevant
to the interpretation of ability modals. On this type of account ability
modals are basically timeless, and the domain of can in (39), that is (j, o,
contains all states in which Fred has the same skills that he has here and
now, regardless of whether these states lie in the past, present, or future. On
the other hand, one might hold that the states in (j o must be contemporaneous
with the current state. Both alternatives seem plausible enough,
but fortunately there is no need to choose between them here, for either
contem-
choice allows us to explain the data. Suppose that we opt for the first
alternative; (j o will then be some set of states whose temporal index is
arbitrary, and the same will hold for (j', o', which is the co-domain of can. But
since the second modal requires as its domain a given set of future states,
the co-domain of can is not an appropriate antecedent, and modal
subordination is blocked. The same conclusion follows if we take (j o to be a
set of contemporaneous states. So in either case we obtain an explanation
for the awkwardness of (39).
To sum up, I have presented a number of cases in which modal subordination
was possible and some in which it was not, and I have argued that
subordi-
these facts could be explained within the framework outlined in the previous
section. In each case, an explanation could be given in terms of what modals
presuppose (their domains) and the objects that they introduce (their co-
codomains).
Every modal -— more accurately: every occurrence of a modal —-
imposes certain restrictions on its domain and co-domain, and it is these
restrictions that decide if modal subordination is possible or not. My claim is
that what I have done here for a handful of examples can be done for
sequences of modals in general, and if that is correct, we don't need a special
theory of modal subordination. The facts about modal subordination are
accounted for by the binding theory in conjunction with an adequate
semantics of modal expressions.