Presupposition General definition: entailment under negation. I don’t regret saying it. I regret saying it. A topic of much interest in philosophy: the background against which truth is computed A topic of much interest in linguistics: presuppositions of parts of a sentence may not become presuppositions of the sentence

Philosophy: The Work of Frege That the name ‘Kepler’ designates something is just as much a presupposition of the assertion ‘Kepler died in misery’ as for the [negative] assertion’. Sense vs. reference. When there is no Kepler, there is no reference, and the truth value of the sentence cannot be determined.

Russell’s alternative: the theory of descriptions A complex logical translation for definite descriptions. ‘The king of France is bald.’  x (King (x) & ~  y ((y≠x) & King (y)) & Bald (x)) The sentence is meaningful: it is false. Scope ambiguity. The king of France is not bald. [He has hair/There is no king of France.]

Strawson:Pragmatics A statement A presupposes a statement B just in case B is a precondition for evaluating the truth or falsity of A. An attempt to avoid tautology. A presupposition must always be true. A= the king of France is bald. B=there is a king of France. Strawson’s solution: truth gaps.

More problems with semantic presupposition Defeasibility. Presupposition can be canceled or ‘suspended’. The projection problem. Complex sentences affect whether presuppositions are interpreted as commitments of the speaker.

Defeasibility Factive verbs. John doesn’t know that Bill showed up late. vs. I don’t know that Bill showed up late. Temporal conjunctions. Sue cried before she finished her thesis. vs. Sue died before she finished her thesis. Background. If Bill Maher invites Susan Faludi, he’ll regret inviting a feminist.

The Projection Problem Presuppositions survive where entailments don’t. It’s possible that the chief constable detained three men. Loony old Harry believes he’s the king of France. If Irv installs a disposal, he’ll regret doing it.

Filters (Karttunen 1973) Either Irv will not install a disposal or he will regret doing it. In a sentence of the form p or q, the presupposition of the parts will be inherited by the whole unless q presupposes r and ~p entails r.

Pragmatic theories Problem with semantic theories. Presuppositions are not stable, and therefore are not context-independent aspects of meaning. Pragmatic theories account for accommodation (Stalnaker). I’m sorry I’m late. My car broke down.

Gazdar: Cancellation Presuppositions are unrelated to truth. Inferences are ordered and must cohere: 1. the entailments of the sentence 2. the clausal implicatures of the sentence 3. the scalar implicatures of the sentence 4. the presuppositions of the sentence

Example Four police officers, if not more, beat up the protestor, if there was one. Entailment. {3,2,1} police officers. Clausal implicature. More than four police possible. Possibly no protestor. Scalar implicature. At most four. Presupposition. There were four police officers.

Conclusion Presupposition is both semantic (lexico- grammatical) and pragmatic (subject to cancellation in context). We conclude that presupposition remains, ninety years after Frege’s remarks on the subject, still only partially understood, and an important ground for the study of how semantics and pragmatics interact. (Levinson p. 224)