Subject: Re: [lojban] Predicate logic and childhood.

From: "Bob LeChevalier (lojbab)" <[email-masked]>
Date: Mon, 30 Apr 2001 19:10:06 -0400

At 03:47 PM 04/30/2001 -0700, Robin Lee Powell wrote:
>On Mon, Apr 30, 2001 at 06:44:27PM -0400, Bob LeChevalier (lojbab) wrote:
> > At 02:48 PM 04/30/2001 -0700, Robin Lee Powell wrote:
> > >2. What is the use of conditionals other than .e?
> >
> > Well, "a" expressing alternation (and anai for conditional) has a pretty
> > clear usage, and onai for exclusive-or does as well.
>
>anai does not have a clear usage, or we wouldn't be having this
>discussion.

It has a clear meaning and usage, but it just happens that this clear 
meaning and usage is NOT that of the colloquial language "conditional", 
which is usually a time or causal connection. There are times when it is 
the right thing to use, and this again is going to be mostly about logical 
arguments wherein statements could either be true or false and it is 
indeterminate for purposes of the argument which is the case. For 
statements about reality, we are generally ONLY concerned with true 
statements and do not generally express false ones without explicitly 
marking them as hypotheticals or suppositionals or counterfactuals of some 
kind.

> > But the use of logical connectives in general is based on the
> > assumption, probably false, that language is attempting to express
> > logical truth. By insisting that the language connectives follow the
> > rules of logic strictly, people will either start thinking in a manner
> > that reflects those rules or they will avoid the use of connectives
> > (or they will break the rules). This is a key design feature for the
> > original purpose of the language as a test of Sapir-Whorf, though I
> > personally think that the formal logical aspects of Lojban don't come
> > into play enough that it will matter much.
>
>Thank you for failing to answer the question. 8)

You're welcome $%)

>No-one has yet managed to tell me what possible use, in actual
>communication, things like o and anai have.

.anai is probably a proper usage to translate "If wishes were horses, then 
beggars would ride". My wife and I HAVE used .anai and na.a on occasion in 
Lojban conversation. "o" is possibly useful when one wants to say that two 
sentences mean essentially the same thing or would be true under the same 
conditions; I am not sure that I have ever used it unless it fell out of an 
onai involving a negation.

But you seem to be denying the possibility that logical argument is a valid 
purpose of "actual communication". Political discussions seem like ripe 
possibilities for logical connectives. But political discussions are not 
statements about reality, but rather about ideas, so that the truth 
conditions are somewhat more uncertain than when you are telling your kid 
what to do.

lojbab
--
lojbab [email-masked]
Bob LeChevalier, President, The Logical Language Group, Inc.
2904 Beau Lane, Fairfax VA 22031-1303 USA 703-385-0273
Artificial language Loglan/Lojban: http://www.lojban.org