From LOJBAN%CUVMB.BITNET@uga.cc.uga.edu Mon Feb 20 20:37:48 1995
Message-Id: <199502210137.AA23310@nfs2.digex.net>
Date: Mon Feb 20 20:37:48 1995
From: ucleaar <ucleaar@ucl.ac.uk>
Subject:      Re: Existence and occurrence of events (was: ago24 & replies)

pc:
> > > > For all events, there is (he says omnisciently) a universe in which
> > > > the event is possible.
> > >       What about the event (state indeed) of being both blue and
> > > non-blue all over at the same time?  Or do you allow impossible universes
> > > (in which case, I withdraw my comments).
> > I allow universes in which what is impossible in other universes is
> > possible. So yes, I mean to allow impossible universes.
>         Not quite an answer to my question, since that does not say
> whether you allow universes which contain LOGICALLY impossible events.

I mean to allow events logically impossible in this universe & any
others we might try to imagine, for two reasons. First, I think we
are capable of hypothesizing an illogical universe. Second, one
notional way of capturing in logical terms the difference in meaning
between "it is now blue and non-blue" and "it is now red and non-red"
is to define the meaning as the set of universes in which the proposition
is true. If we don't allow logically impossible universes then that
method doesn't work.

> And, if you do (as I gather you intend), does every such universe contain
> ALL events or are these universes distinguishable by containing different
> events -- and perhaps defined by different impossible events?

They're distinguishable by containing different events, some of which
might be impossible.

> Are your impossible universes, in short, classically impossible or
> something like (but perhaps different from) relevantly impossible?
> I'm not sure that this latter matters, but I would like to get your
> cosmontology sorted out.

I don't know what these kinds of impossibility are.

> Do we disagree about what _nu_ (which is surely not a selbri?) means?

{Nu} expresses a predicate, doesn't it?

> I thought the issue was about whether certain things existed.

This is relevant to the question of what {nu} means.

> To be sure, if we come at these things by words, we have to know what
> thewords mean to answer the question of whether there are any, but
> that is not enough. We also have to look and see in the appropriate
> place. I suspect we do not agree about where to look.  Following logic
> (in the way suggested and since this is a logical language in a very
> genetic way), I look to what the language says, which seems to be that
> any event we can name exists is some washed out sense of "exists" --
> which nonetheless embraces _da_.

I hope you're not thereby ruling the possibility of truthfully asserting
that no member of some namable category exists - e.g. "-Ex beeblejig(x)".

> You want (apparently) to look in the
> (or some) greater extralinguistic world.  Happily, you have now expanded
> that world to the point where it can (should? must?) include all the
> guys I want in, so we ought to be back in synch.

I think we are in synch. And I am reassured by {da'i(nai)} which - in
your terms - will serve to indicate whether the existence is strong
or weak. I would still like to know whether by default {da poi broda}
is equivalent to {da poi da'inai broda} (strong existence, in the time
of this world) or to {da poi da'i broda} (weak existence, in the time
of some world). I very very very much hope that the default is
{dahinai}, else if the default is {dahi} then all utterances without
explicit {dahinai} will be true.

---
And