Presuppositions and Pronouns - Nijmegen Centre for Semantics

The satisfaction theory 105
Karttunen and Peters's: it takes as its point of departure the idea that the
predictions of the satisfaction theory are correct, but occasionally require
strengthening. The argument goes as follows: lO 10
(31) The argument/rom from improbability
a. The speaker is presupposing that %. X.
b. It is more plausible (or less controversial) to assume that xX
than to assume that X. %.
c. Therefore, the speaker is probably assuming that %. X.
This is similar to the first argument in that both assume that the conditional
presuppositions which cause the proviso problem are deficient in some way,
but in (31) Karttunen and Peters's original idea that these conditionals are
purely truth-functional has watered down to the assumption that they are
comparatively unlikely, or more controversial than their consequents.
Prima facie, the argument from improbability seems to be much more
plausible than the argument from truth-functionality, but on closer
inspection it turns out to be equally inadequate. To begin with, the argument
requires that X % be more plausible than but it is obviously impossible
for a proposition to be more plausible than a proposition which it entails.
Therefore, this argument will not work unless we give up our construal of
natural language conditionals in terms of the material implication. For
example, if we adopted '>' as defined in (14) instead of '—»', '~', 'if cp