Re: Knowledge and belief

["Jorge J. Llambías" <jorge@INTERMEDIA.COM.AR>]

Lojbab:
>>No argument against that. You can claim djuno as long as you
>>presuppose jetnu. If later you find out that jetnu doesn't hold, then
>>you will withdraw the djuno claim as well.
>
>But this I think is wrong.  if I claim djuno, and we agree that it is
>true now,

But we don't agree that it is "true now". Rather, we "now agree"
that it is true. We might later realize that we were wrong.

>but then if it turns out that it is false (through presupposition
>failure or some other reasoning) then at that time we can say that it is
>false, but I do  not see how we can make the former knowing "false".

Just as we made the former being true "false". We were wrong,
that's all.

> What
>has happened is that the universe of discourse aboiut which the former
>claim was made, turned out not to be the real world.

Is that really what happened? Couldn't it be that we simply made a
mistake about the real world? I don't think the universe of discourse can
be changed like that so as to force a claim to be true.

> This makes the
>statement not far removed from "I know that Sherlock Holmes lived on Baker
>Street".

Your presupposition there is that Sherlock Holmes lived on Baker Street,
which is true in context.

>In any event, WITH the epistemology place present, something false by one
>epistemology (hindsight) can be true by another epistemology.

My point was that {djuno ko'a fo ko'e} presupposes {ko'a jetnu ko'e}.
Same ko'a and same ko'e.

>I find it hard to accept that a statement can be true at time T, and then
at
>time X which is after T, we can say that it was NOT true at time T.

Personally, I prefer to think of truth values as outside of time as
well. Just like the number 5 does not have a duration in time, neither
does a truth value. But our agreement at time T that a statement is
true does not mean that we cannot later change our minds and
admit that we were wrong.

> It seems
>to me that there are presuppositions in every sentence, and involing hidden

>presuppositions in order to make things work out makes it hard to claim
that
>the language is working as a "logical language".  If there are
presuppositions,
>that fact should be plainly evident in the claim.

In the case of djuno, the presupposition is plainly evident, isn't it?

>I am also bothered by the fact that time is critical to the truth of such a
>claim. Lojban of course has tense optional.  I am bothered that truth of a
given
>proposition at a given time could depend on when the proposition is stated.

I'm not sure I understand what you mean here. When a given sentence
is uttered can certainly make a difference as to the truth value.

co'o mi'e xorxes