Message-Id: <m0qnci4-00005XC@xiron.pc.helsinki.fi>
Date:         Thu, 22 Sep 1994 11:15:18 +1000
Reply-To:     Desmond Fearnley-Sander <dfs@HILBERT.MATHS.UTAS.EDU.AU>
Sender:       Lojban list <LOJBAN%CUVMB.bitnet@FINHUTC.hut.fi>
From:         Desmond Fearnley-Sander <dfs@HILBERT.MATHS.UTAS.EDU.AU>
Subject:      Re: any? (response to Desmond)
To:           Veijo Vilva <veion@XIRON.PC.HELSINKI.FI>
Content-Length: 1406
Lines: 29

 John Cowan:
>Three-valued logics can be made to work, but they are messy.
>
Although, it is true that in dr most sentences are neither true nor false,
I *absolutely do not* think that three-valued logics are the way to fix the
fact that classical logic does not model everyday reasoning.  Make that
"neatly model" if you prefer.

Desmond:
>> I may know a lot about Charles and Diana but not know whether
>> they live in the same county.  I lack that specific information.  For me
>> the sentence "Charles and Diana live in the same county." is neither true
>> nor false.  Of course *in fact* it is either true or false, but that is not
>> a linguistic matter.  (I like the idea that language and reality are
>> independent worlds, that language is for conveying and analysing
>> information and that matters of fact only impinge on language by
>> influencing what we find worth saying.  Philosopher's might have a field
>> day with this.  I'd better retract it.)
>>
John Cowan:
>Indeed.  I think that you are on firmer ground to say that "C. and D. live
>in the same county" is either true or false >tout court<, but that you don't
>know which.  This puts the problem onto knowledge (epistemology), which is
>known to be a sticky area, and leaves truth value simple.
>
Just different ground, I think.  Knowledge is what language deals in.
Simple truth values are fine for simple matters of fact.

Desmond