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510 Tutorial Sept/11/19

Assertion, presupposition, and

Assertion: “ in which something is claimed to hold” (SEP) — things that are “asserted” are part of the claims made by the

Example of assertion:

Speaker A: Did you read the book that John wrote?

Speaker B: Well, I read the book that Mary wrote. what is asserted by speaker B?

Asserted: That speaker B read Mary’s book

A sentence is true only if what it asserts is true

Presupposition: Presupposed is “taken for granted” in the utterance Information that is presupposed is not part of the “claims” made by the sentence.

Example of presupposition:

Speaker A: Did you read the book that John wrote?

Speaker B: Well, I read the book that Mary wrote. what is presupposed by speaker B?

Presupposed: That Mary wrote a book

A trick for detecting presuppositions!

Presuppositions “survive” .

A) I read the book that Mary wrote

B) I didn’t read the book that Mary wrote.

— In B, the assertion that speaker B read Mary’s book is “cancelled” by the negation didn’t — This negation has no effect on the presupposition that Mary wrote a book, which “survives” in both A and B

A sentence is true only if what it presupposes holds, and a sentence is also false only if what it presupposes holds

Implicature: Implied information is understood from an utterance but not explicitly stated — like presupposition, it is not part of the assertion (or “claims”) made by the sentence.

Example of implicature:

Speaker A: Did you read the book that John wrote?

Speaker B: Well, I read the book that Mary wrote. what is implied by speaker B?

Implied: That Speaker B didn’t read the book that John wrote

A trick for detecting implicature!

— The information that is implied is logically consistent with the utterance, but so will its negation:

A) Well, I read the book that Mary wrote, but I didn’t read John’s book (implied information)

B) Well, I read the book that Mary wrote, and I read John’s book (negation of implied information) -Well, I read the book that Mary wrote, and I didn’t not read John’s book (negation of implied information)

A sentence is logically consistent with its implication, and with the negation of its implication

Activities:

1. Consider the following dialog: Speaker A: Did you eat all three donuts?

Speaker B: Well, I ate the two pink donuts. a. What, if anything, does speaker B assert here?

Assertion: They ate the two pink donuts b. What, if anything, does speaker B presuppose?

Presupposition: There are two pink donuts c. What, if anything, does speaker B imply?

Implicature: They did not eat the third donut!

Clarification about this :

There was some discussion in as to whether the that the third donut is not pink was a presupposition. As we can see, this does pass our presupposition test:

A) I ate the two pink donuts B) I didn’t eat the two pink donuts

Negating speaker B’s sentence does not alter the that the third donut is not pink.

However, the presupposition here actually has to do with the third donut. Rather, the presupposition is about the uniqueness of the two pink donuts. This is something introduced by the definite determiner the. If the sentence I ate the two pink donuts is uttered outside of a where there is a third donut, we still have the intuition that the two mentioned donuts are the only pink ones, with no to any other possible donuts. Because a third donut was mentioned in this context, we infer that it cannot be pink if the two donuts mentioned by speaker B are uniquely pink, but the presupposition itself does not directly reference the third donut.