This paper discusses exceptional behavior of definite process nominals with full argument structure, as opposed to other nominals, in terms of their presuppositions. The author observes that in a sentence like John would protest the destruction of the city, the expected referent of a noun phrase like the destruction of the city need not be presupposed to exist, i.e., the city need not have been destroyed. This contrasts with a sentence like John would protest the war, where either there must be a war in the actual world, or a relevant hypothetical war must be under discussion. The author proposes an analysis of this and related phenomenon in terms of coercion into propositions; a process nominal can be coerced into a proposition which existentially closes the description within the noun phrase, while other noun phrases cannot be coerced in this way.