OK, here's something else about how knowledge ascriptions suggest/presuppose truth; it may not be more coherent, but it should be shorter (never mind) or funnier.
Usually, I think, it would be odd to respond to:
Did you know that they stopped making lead paint in the 1940s?
the proper response is not
I don't know that
but
They didn't stop till 1978!
(And there's a pretty easy Gricean explanation. "I don't know that" isn't as informative as "They didn't stop till 1978!") Nevertheless, "I don't know that" would strictly speaking be true, as would "Nobody knows that." If you wanted to be properly sarcastic, you could say "Nobody knows that" and convey that it's not true.
Here, I think the knowledge-that question definitely suggests, if it doesn't presuppose, the truth of the embedded claim. (If you ask "Do we know that..." it doesn't presuppose it, I guess; or any other first-person ascription. Then if you knew that the presupposition was true you would already have the answer to the question.)
Now you might think that the "Nobody knows that!" response isn't available to knowledge-wh questions. If you ask
Do you know where the game is?
and I say
Nobody knows where the game is!
the only obvious reason is that, well, that information isn't available. Maybe the location is yet to be determined. Since "Somebody knows where the game is" doesn't entail the truth of any particular embedded proposition, saying "Nobody knows where the game is" doesn't suggest the denial of any particular embedded proposition.
However: A friend of mine once told me of a dream of hers involving mysterious voices telling her, "Beware of the quilted cohina!" I replied (over e-mail) that I didn't know what a cohina was, but as I was in a library I should go look it up. The response:
No one knows what a cohina is!
meaning, it wasn't a real word, but only a word in the dream. In this case "Someone knows what a cohina is" entails or presupposes that there is an answer to the question, "What is a cohina?" and that is false. Nevertheless, ordinarily this would be an odd way of saying "There is no such thing as a cohina." Why it worked this time, I don't know.
Posted by Matt Weiner at November 9, 2005 01:55 PMI think that "Do you know where the game is?" clearly presupposes that there is a game and that it has a determinate location. I thought that "Noone knows where the game is" would be natural if there were no game at all, even before reading down to your dream example.
Posted by: P.D. at November 9, 2005 03:08 PMI second P.D: in the case where there is no game, "no one knows where the game is" struck me as exactly as correct as "nobody knows that" above. "x knows where the game is" does entail that there is a p which is an answer to the question "where is the game?" and x knows p.
Posted by: Anders Weinstein at November 9, 2005 09:34 PMI'm not claiming that "Nobody knows where the game is" is incorrect when there is no game; it's just that to me, it didn't seem to convey presupposition failure in the way that "Nobody knows what a cohina is." Of course, since I made the example up, my intuitions are particularly suspect here.
Actually I do have a theory about any alleged difference. It would be impossible or at least very unusual for "cohina" to have a meaning as a word of English and for no one to know what that meaning is. And in this situation my assumption was that the dreamer knew what the word meant. So the only available interpretation is that nobody knows it because the presupposition of the question fails.
That's not the case in the game example; it could be that no one in the relevant domain knows where the game is.
Posted by: Matt Weiner at November 10, 2005 07:36 AMHere's another case, though I don't know it to shed additional light on the matter.
Consider what would happen if the pilot made the following announcement, on a flight bound from New York to LA:
"Ladies and gentlemen, none of you know that this flight will crash in the Andes before reaching its final destination."
My guess: Panic and confusion. When the co-pilot explains:
"None of you know it because it isn't true. This plane will not crash in the Andes."
The passengers are apt to think the pilot has played a not-very-funny joke, misleadingly telling them that the plane will crash in the Andes.
Posted by: Chase Wrenn at November 10, 2005 01:26 PMA mis-hearing of an Eagles lyric ("warm smell of coleus" as "warm smell of cohinas")?
Posted by: Ken Houghton at November 11, 2005 09:04 AM