The projection problemThere is a basic expectation that the presupposition of a simple sentence will continue to be true when that simple sentence becomes part of a more complex sentence.This is one version of the general idea that the meaning of the whole sentence is a combination of the meaning of its parts.However,the meaning of some presuppositions (as parts) doesnt survive to become the meaning of some complex sentences (as wholes).This is known as the projection problem.In example 12,we are going to see what happens to the presupposition q (Kelly was ill) which is assumed to be true in the simple structure 12c.,but which does not project into the complex structure 12h.In order to follow this type of analysis,we have to think of a situation in which a person might say: I imagined that Kelly was ill and nobody realized that she was ill.12a.Nobody realized that Kelly was ill.(=p)b.Kelly was ill.(=q)c.pq(At this point,the speaker uttering12a. presupposes12b.)d.I imagined that Kelly was ill.(=r)e.Kelly was not ill.(=NOT q)f.rNOT q(At this piont,the speaker uttering12d.presupposes12e.,the opposite of 12b.)g.I imagined that Kelly was ill and nobody realized that she was ill.(=r&p)h.r&pNOT q(At this piont,after combining r&p,the presupposition q can no longer be assumed to be true.)In an example like 12,the technical analysis may be straightforward,but it may be difficult to think of a context in which someone would talk like that.Perhaps example 13will contextualize better.In an episode of a TV soap opera,two characters have the dialog in 13.13Shirley:Its so sad.George regrets getting Mary pregnant.Jean:But he didnt get her pregnant.We know that now.If we combine two of the utterances from 13,we have the sequence, George regrets getting Mary pregnant;but he didnt get her pregnant.Identifying the different propositions involved,as in 14,we can see that the presupposition q in 14b. does not survive as a presupposition of the combined utterances in 14e.14a.George regrets getting Mary pregnant.(=p)b.George got Mary pregnant.(=q)c.pqd.He didnt get her her pregnant.(=r)e.George regrets getting Mary pregnant,but he didnt get her pregnant.(=p&r)f.p&r NOT qOne way to think about the whole sentence presented in 14e. is as an utterance by a person reporting what happened in the soap opera that day.That person will not assume the presupposition q (i.e. that George got Mary pregnant) is true when uttering 14e.A simple explanation for the fact that presuppositions dont project is that they are destroyed by entailments.Remember that an entailment is something that necessarily follows from what is asserted.In example 13,Jeans utterance of he didnt get her pregnant actually entails George didnt get Mary pregnant as a logical consequence.Thus,when the person who watched the soap opera tells you that George regrets getting Mary pregnant,but he didnt get her pregnant,you have a presupposition q and an entailment NOT q.The entailment (a necessary consequence of what is said) is simply more powerful than the presupposition (an earlier assumption).The power of entailment can also be used to cancel exastential presuppositions.Normally we assume that when a person uses a definite description of the type the X (for example, the King of England),he or she presupposes the existence of the entity described,as in the utterance of 15a.Also,in any utterance of the form X doesnt exist,as in 15b.,there is an entailment that there is no X.But does the speaker of 15b. also still have the presupposition of the existence of the entity described?15a.The King of England visired us.b.The King of England doesnt exist!Instead of thinking that a speaker who utters 15b. simultaneously believes that there is a King of England (=presupposition) and that there is not a King of England (=entailment),we recognize that the entailment is more powerful than the presupposition.We abandon the existential presupposition.As already emphasized,it may be best to think of all the types of presuppositions illustrated in Table 4.1 as potential presuppositions which only become actual presuppositions when intended by speakers to be recognized as such within utterances.Speakers can indeed indicate that the potential presupposition is not being presented as a strong assumption.Possessive constructions such as his car have a potential presupposition (i.e. he has a car) which can be presented tentatively via expressions such as or something,as in 16.16a.Whats that guy doing in the parking lot?b.Hes looking for his car or something.In 16b.,the speaker is not committed to the presupposition (he has a car) as an assumed fact.It is worth remembering that it is never the word or phrase that has a presupposition.Only speakers can have presuppositions.Ordered entailmentsGenerally spea