A Blacked-Out City

----- By J. L. Speranza


---------------- IN OTHER threads we are discussing Grice's



A: Did Charlie watch "Star Trek" tonight?
B: He was in Boston.



Surely, Grice says ("Logic and Conversation", Way of Words, iii):

+> No.



i.e. the implicature is "no".

For A and B both know as per the following

(p) A and B know that Boston was blacked-out
yesterday and (p).


We need the recursive loop, because it's not just a matter of A knowing

(B) Boston was blacked-out yesterday

and B knowing (B) too; they have to each know (if you excuse me the split) that (B) and so ad infinitum, which is best understood as (p). It cannot be 'non-controversial' topic (as Grice's other example: My aunt's cousin went to that concert) because this _trades_ on common-ground status, as Grice calls it.

Common-ground status Grice symbolises by square brackets

[Boston was blacked-out yesterday]

Applying PERE (principle of economy of rational effort) on the ground that the stakes are not TOO high, we DO NOT say "No", knowing that the negation or negative answer to the yes/no question is thus 'implicated' in a defeasible way.

On the other hand, he can go, "Why do you ask?" Etc.