Re: knowledge and belief

["Mark E. Shoulson" <shoulson@CS.COLUMBIA.EDU>]

>Date:         Mon, 12 Jan 1998 20:25:22 -0300
>From: "=?iso-8859-1?Q?Jorge_J._Llamb=EDas?=" <jorge@INTERMEDIA.COM.AR>
>
> la ~mark cusku di'e
>>Let's take Jorge's reading for now (which I rather like), that "X knows Y"
>>is the same as "X believes Y, and incidentally the I (the speaker) also
>>believe Y."  (which would make using "know" in first person redundant,
>>btw).
>
>Actually, in my reading the presupposition is stronger than that the
>speaker believes Y. The presupposition is that Y is true. To see that
>there is a difference consider these:

Um... what's the difference?  If I'm saying something is true, isn't that
the same as saying that I believe that it's true (assuming I am not lying)?
So saying "Fred knows that Steve died" is saying (a) Fred believes that
Steve died, and (b) Steve really did die... or rather, *I* think so (I
could be wrong of course, but I don't think so).  What's the difference
between asserting something to be true and saying that I believe it to be
true?

>- John knows that lojbab goes to the market.
>- na'i John can't know that because lojbab does not go to the market.

Is the second sentence said by the same person or someone else?  If the
latter, then he is correcting the first person's belief as well.

>- John believes that lojbab goes to the market, and so do I.
>- You two may well believe it, but the truth is that he isn't going.

Oh, I see.  But when I say "John believes that lojbab goes to the market,
and so do I," then so far as I know, it's *true* (or I wouldn't be
believing it.  I do not believe people knowingly believe falsehoods).

>In the first case, there is a failure of presupposition. In the second
>case there is nothing but mistaken beliefs. So using "know" does
>not just require that the speaker believes it, but more than that,
>it requires that the speaker take for granted that the audience
>also believes it.

Isn't presupposition a belief?  I'm not sure I see the difference.

~mark