Subject: Re: [lojban] Re: [loglanists] Sets

From: [email-masked]
Date: Mon, 18 Feb 2002 20:37:09 EST

In a message dated 2/18/2002 6:12:37 PM Central Standard Time, [email-masked] 
writes:

> Nobody has ever claimed that existential ("some") statements did not
> have existential import. The whole point of saying "Some swans are
> white" is to assert that there *are*, indeed, swans that are white.
> 

Well, some have claimed it for negative particulars ("Some S are not P"). In 
fact, Aristotle apprears to have done so at least occasionally.

<> Lewis Carroll, as I recall, tried to
> compromise by giving existential import to "some" statements, but not to
> "all" statements (so that, by his scheme, "All unicorns are white" is
> acceptable, but "Some unicorns have halitosis" is not).

Carroll took the traditional view: both have existential import.>

Carroll is a hard case. He published two logic books and wrote a third and 
through all of them he waffles. Not about "all" and "some", but about "no" 
and "some... not." The right answer, for all sorts of reasons, is that 
neither of these has existential import, but are simply the negations of 
their diagonal opposites, but that was too radical for Dodo, so he tried 
making "no" free but keeping "some...not ..." existential, then a bit of the 
oposite and finally a half-hearted return to orthodoxy, with the clear 
recognition that it was wrong. (The chief virtue of the affirmative- 
existential, negative -not system is that all the possibilities are definable 
in it. And, of course, that it is Aristotle's final system.see 
http://plato.stanford.edu/entries/square/.)

<Lojban takes the second view, since both forms can be expressed:
one using number + predicate directly (= "All swans"), the other
using a bound variable and a relative clause ("All X such that").>

At last! Can I take this as the official word? No more changing next week, 
when I try to rely on this? No smooth-talking logicians muddying the water?
And what about the negative cases?
Wait! Just to be sure: the first {ro broda} is esistential, the second {ro da 
poi broda} is not. Right?