Presupposition Projection: the New Debate

A powerful intuition behind much recent research is that a presupposition must be satisfied in its context of evaluation. The relevant notion of context is, in Stalnaker’s terminology (Stalnaker 1978), the ‘context set’, which encodes what the speech act participants take for granted (we will say ‘context’ for short). But the simplest version of this analysis faces immediate difficulties with complex sentences: John is incompetent and he knows that he is does not require that the speech act participants already take for granted that John is incompetent, since this proposition is asserted, not presupposed. The dynamic approach solves the problem by postulating that the second conjunct is evaluated with respect to a local context, obtained by updating the global one with the content of the first conjunct; this explains why the presupposition of the second conjunct is in this case automatically satisfied. This analysis is captured by the dynamic rule stated in (1): the update of a context C with a conjunction is the successive update of C with each conjunct.