Inference, Entailment, Presupposition

Pragmatics

Deductive inference

• Cannot be cancelled - must be true if the premises are true

• Entailment is a form of deductive inference

• E.g.: All the beans in this bag are white —> this bean is from this bag = this bean is white

Induction

• Statistical generalisation

• Probable but not confirmed

• E.g.: million beans in bag, first 1000 are white —> all beans in this bag are white

Abduction

• Needed for hypothesis forming

• Produces hypotheses we can then test

• Uses set of observations to reach most likely conclusion

• Conclusion considered (likely) to be true, doesn't have to be

• Implicatures are abductive inferences - hypotheses the speaker can entertain

• Presuppositions are abductive in nature

Entailment

Something that must be true if the premises are true.

• semantic in nature

• not defeasible

• cannot disappear in any linguistic or non-linguistic context

Tests for entailment

• Lost with negation

• Lost with interrogation

• Cannot be directly contradicted (bought him roses but didn’t buy him flowers)

Presupposition

Piece of information or proposition whose truth is taken for granted in the utterance of a sentence

• Speakers or utterances carry presuppositions but not sentences

Tests for presupposition

• Holds if negated

• Holds in interrogation

• Cancellable/fallible (abductive in nature)

Presupposition triggers

• Factive verbs

• It-clefts

• Pseudo-clefts

• Definite determiners

• Temporal clauses

• Wh-questions (interrogation/negation tests don’t work here)

• Iterative expressions

• Counterfactual conditions

Things that do not presuppose

• Reporting verbs cancel a presupposition

• Clefting in French doesn't always carry the same presupposition that it would in English

• If-clauses/hypotheticals do not presuppose

• Inconsistency with background assumptions or real-world knowledge

  • Presuppostions can be suspended by ‘reduction arguments’ - arguments that proceed by eliminating each of the possibilities - in discourse

Truth conditions

Conditions that the world must meet for the sentence to be true

Upward entailment

From subset to set (every woman is roasting beef —> every woman is cooking)

Downward entailment

From set to subset (no woman is cooking —> no woman is roasting beef)