PHIL 012 – Symbolic Logic
March 28, 2001
Announcements
Exam 1 – hand back Monday
Homework 7 – come to my office after class or I’ll bring them to class on Friday
Homework 9 – due Monday 1-22 except #15, 17, 21. Note that #2 is an exercise.
Sara Leland will be out of town next week. Her office hours will be cancelled. However, she’ll have extra hours on Saturday 4/7 at 3:00.
Implicature vs. meaning.
HP Grice: Semantics vs. Pragmatics
Semantics – meaning
Pragmatics - use
“Mars appears to be red” was once thought to imply that Mars can’t actually be red.
However, if we distinguish meaning from use, the meaning of the statement doesn’t have any bearing on Mars’ actual color. The “implication” that Mars isn’t actually red” is a consequence of use.
“Mary believes that Armand is having an affair.” Could be thought to imply that Mary doesn’t know that Armand is having an affair. However, if we distinguish meaning from use, then we see that the second claim is not part of the meaning of the first, but might only arise from the context of use.
The meaning of a statement must be contained within the statement.
A conversational implicature is something that we conclude not from the statement itself (its meaning), but from the fact that a person utters the statement.
The authors use “You can have either soup or salad.” To illustrate the claim that the exclusive interpretation of disjunction is a result of conversational implicature whereas the exclusive interpretation is its actual meaning.
Grice’s test:
Statement 1: You can have soup or salad.
Statement 2: You can’t have both.
If it makes sense to add additional statements that deny statement 2 without directly contradicting statement 1, then statement 2 is a conversational implicature.
On the other hand, if in order to deny statement 2 we must contradict statement 1, then statement 2 is a meaning of statement 1.
The waiter could say “You can have soup or salad or, you could have both.” This denies statement 2 without directly contradicting statement 1, therefore statement 2 is just a conversational implicature, not a meaning of statement 1.
Max is at home unless Claire is at home.
~Home(Claire) -> Home(Max)
not
~Home(Claire) <-> Home(Max)
Home(Claire)Home(Max)~Home(Claire) -> Home(Max)
TTFTT
TFFTF
FTTTT
FFTFF
Home(Claire)Home(Max)~Home(Claire) <-> Home(Max)
TTFFT
TFFTF
FTTTT
FFTFF
Because the speaker could go on to add If Claire is at home, I have no idea where Max is without contradicting the original statement, we see that the second implication of the biconditional is a conversational implicature, not part of the meaning of the statement.
~Home(Claire) <-> Home(Max)
~Home(Claire)->Home(Max) ^ Home(Max)->~Home(Claire)
Problem 12. Suppose Claire asserts the sentence Max managed to get Carl home. Does this logically imply, or merely implicate, that it was hard to get Carl home? Justify your answer.
Problem 13. Suppose Max asserts the sentence We can walk to the movie or we can drive. Does his assertion logically imply, or merely implicate that we cannot both walk and drive? How does this differ from the soup or salad example?
Soup or salad: The waiter says Does his assertion logically imply, or merely implicate that we cannot both walk and drive? How does this differ from the soup or salad example?
Soup or salad: The waiter says, You can have either soup or salad.