Re: On {lo} and existence

[jorge@PHYAST.PITT.EDU]

And:
> > > I am immune to arguments from pragmatics.
> > How are we supposed to understand what things nanmu in that imaginary
> > world? Only by analogy with the real world, otherwise "I told a story
> > about a man with three heads" would be equivalent to "I told a story
> > about a woman with seven legs".
> I have been supposing that predicates are independent of worlds.

No, you haven't. In some world you accept that "x1 is a man" can be
satisfied by something with three heads. That means that that predicate
is not world independent. In one world, being a man does not exclude
having three heads, and in another world it does. That makes the
predicate world dependent.

If you define the predicate by listing the things that satisfy it,
then obviously it is world dependent. If you define it by listing the
properties of the things that satisfy it, then again it is world
dependent, because "having three heads" is allowed in one but not in
the other.

> If I wanted to say "I told a story about a man (who may or may not
> exist in this world)", I'd say {mi te cfika lo dahi nanmu}.

I don't understand. If you predicate about something, that something
either exists or doesn't exist in this world. If you say {mi te cfika
da}, I can ask {xu da poi se te cfika do xanri}, and the answer should
be either yes or no. It may be that you don't know the answer, but
in predicate logic it is either true or false.

> If we accept that my attempt to uphold the view that {lo} does not
> {da poi} will not win consensus, then {mi te cfika lo nanmu} will
> be equivalent to {da poi dahinai nanmu zohu mi te cfika da}, which
> says - to me - that the man exists in this world.

Yes, only if it is true that {ro da poi nanmu cu zasti}. The man exists
because being a man entails existing, i.e. it is part of the meaning
of {nanmu}, nothing else.

> > It is a matter of what do we accept as a nanmu. In English, we quite
> > happily accept a character of fiction to be a man. We could do the
> > same in Lojban, and then there would be no problem with {mi te cfika
> > lo cibyselstedu nanmu noi nanmu}, but yes with {ro nanmu cu morsi}.
> I quite happily accept that a character of fiction be a man *in that
> fictional world* but not in this world.

We are failing to communicate. The background world is the world where
the utterance takes place. In that world, each predicate is supposedly
well defined. I can talk *in this world*, i.e. in the world where I'm
making the utterance, about fictional characters. When I say in English
that Sherlock Holmes is a man, I am saying that of a character of fiction
in this world. I am not entering the fictional world where Sherlock
really exists and becoming myself a fictional character in order to
make the utterance. Thus, I am talking of something that satisfies
*in this world* the predicate "...is a fictional character". Then,
in English, the predicate man() can be satisfied *in this world*,
by characters of fiction. On the other hand, the same word has a
different meaning *also in this world*, when I say "all men are
mortal". This is because in English, like in any natlang I suppose,
words don't have fixed meanings. In predicate calculus, we probably
don't want to use the same word for several different predicates.
In Lojban, I suppose we don't want that either. So nanmu() probably
cannot be truthfully predicated of fictional characters. Or maybe
it can, in which case {ro nanmu cu morsi} is false.

> What I've been trying to
> get at is that for most predications to be true in universe X, their
> sumti must also exist in universe X. E.g.:
>
>  Real    Fictional
>  false   true         Sherlock Holmes solved many crimes.

Agreed that it is false, but not because there is no Sherlock Holmes,
since obviously there is. The name "Sherlock Holmes" has a well defined
referent, namely the fictional character that is a fictional character
in this world. It is false because it is false that characters of fiction
can solve real crimes. On the other hand, the predication "Sherlock Holmes
du Sherlock Holmes" is true, and so is "Sherlock Holmes is a character
of fiction".

> while for a few predicates to be true in universe X, certain of their
> sumti needn't exist in universe X. E.g.:
>
>  Real    Fictional
>  true    false        I mentioned Sherlock Holmes.

Unless the utterance is produced in that fictional world, I don't see
how can you evaluate its truth value there. Utterances only make sense
in the world where they are produced. The sentence you wrote corresponds
to two different utterances. It would seem to be a sentence that by
simply uttering it, it becomes true, so if someone utters it in that
fictional world, it is a true utterance.

> > My question is, is that a mlatu? Does it satisfy the predicate "mlatu"?
> > If it does, then I have no problem to say you draw {lo mlatu}. If it
> > doesn't, then you drew something else, perhaps {lo cibyselstedu mlatu}.
> My answer is: Yes, it is a mlatu, and yes it satisfies the predicate
> "mlatu", but that {da poi mlatu zohu mi te pixra da}, which
> is equivalent to {da poi dahinai mlatu zohu mi te pixra da},
> is false.

Then it doesn't satisfy the predicate {mlatu}. {le se pixra cu mlatu} is
false. I don't care what the truth value of another utterance of the
same sentence would be in some other world, because I'm speaking in this
world, so I only know the meaning of words in this world. Utterances
have truth values only in the world in which they are uttered.
Sentences don't have truth values.

> The way I hope we can agree to say this is {mi te pixra lo dahi mlatu}.

Yes, meaning "I draw something that is not quite a cat, but has enough
of the properties of cats that I can call it cat and you can understand
what I mean, even though da poi mi te pixra na mlatu."

No recourse to imaginary universes that take us outside the scope of the
language by redefining its predicates.

> > > Or, put another way, it is possible for
> > > the model to exist only in an imaginary world created by the picture.
> > By "exist" here you don't mean logical E. The model, or subject, obviously
> > has to exist (E) to satisfy {mi te pixra da}. Now, why would you
> > call it a mlatu if it doesn't mlatu?
> It does mlatu. But it is in the picture-world that it is a mlatu.

But that doesn't make sense. The utterance is not produced in the
picture-world. I can only make utterances with sumti that have referents,
(not necessarlly flesh and blood ones) in this world.

> In the world where I create the picture, it does not mlatu; it is
> nought but a se pixra.

And you are referring to it in this world, so it doesn't make any sense
to say that in some world it does mlatu. It would be equally informative
(except for pragmatics) to say that in some other world it does gerku.
The advantage of using the word {mlatu} over the word {gerku} in this
case, is not that the object does mlatu in some given universe, because
it is equally the case that it does gerku in some other universe. The
advantage of {mlatu} is that the object does something very similar
if not quite exactly the same of mlatu *in this universe*.

> > That it is a mlatu in another world tells us nothing, because we only
> > know what predicates mean in this world.
> Crucially, I disagree. For example, {slabu} means "exists for a long
> time", and is independent of the universe in which that existence
> occurs.

Total digression: {slabu} does not mean that. It means "familiar,
well known", and has nothing to do with elapsed time. The gismu
list uses it to make lujvo for "ancient", "age", and "historical",
but that to me doesn't make any sense.

The gismu list also says that {citno} means both "young" and "short
in elapsed duration". Those two are different meanings. "Young" only
applies to living things, or by extension to things with an expected
maximal duration. For example, I never understood whether we would
use {citno zdani} for "new house", since houses don't really have
expected durations, so we don't say that they are young. Also, would
we say that a short event is a {citno fasnu}, a "young event"?
I don't think so. I think {citno} will only be used for living things
or other things with "lifetimes".

"Long in elapsed duration" and "short in elapsed duration" are
{clani temci} and {tordu temci}. I don't think {citno} has much
to do with this.

A reason that I want to keep the meaning of {slabu} safe from
the contamination by "old" is that it is the perfect translation of
the other meaning of "know", the one not covered by {djuno}.
I have used and will continue to use {selsau} for Spanish "conocer",
Esperanto "koni", French "connaitre", etc.

Now, back to our discussion, let's take {temci} instead of {slabu}.
You say that the meaning "time elapsed between two events" is
independent of the universe. Ok, but it doesn't really matter,
since all my utterances in this universe must refer to objects
of this universe (real or imaginary ones, but of this universe).

> Another example: if we are told that Aragorn's eyes are blue
> then it is legitimate for us to conclude that were we to behold his
> eyes we should perceive their colour as blue.

Right. The question is, how is {blanu} defined? Is it true that
characters of fiction can be blue? Is it true that characters of
fiction can have eyes? This has to do with the definition of
{blanu} and {kanla}. If they can, then there is no problem.
If they can't, then {la Aragorn se kanla lo blanu} is simply
false, because the character Aragorn is not in relationship
"se kanla" with any blue thing. It boils down to the definition
of {kanla}.

In other words, our conclusion may be legitimate, but we may be
starting from a false premise. It depends on what things can be
said to have eyes in our language. I don't see any reason to
suppose that characters can't be said to have eyes, but then
eyes don't have to be flesh and blood objects.

> > > I guess life
> > > would be easiest for all concerned if we agreed that by default
> > >    <selbri> = dahinai <selbri>
> > >    nu = dahi nu
> > > and that the inconsistency is an accident of history.
> > I insist that it is an inconsistency only if you view it through the
> > many worlds interpretation. If you let the {nu broda}s of this world be
> > things that never happen, then there is no inconsistency, just a very
> > generous definition for what counts as a {nu broda}.
> I have yet to see such a definition. As I've said before, I don't
> think something can be an event if it doesn't happen, just as, say,
> something can't be wine if it is not material.

And I agree with you. I'm saying that a different definition of {nu}
is possible and consistent, not that it is desirable. You can define it
along the lines of guaspi's definitions. For each <bridi>, give a list
of all things, real and imaginary, that satisfy the predicate {nu<bridi>}.
I'm sure you won't budge at the impracticality of it.

> In both cases, though,
> we can conceive of imaginary events that don't happen in this world
> and imaginary wine that is not material in this world.

Right, by analogy, but I thought you wanted to leave pragmatics out
of it.

> So if {nu}
> is defined as something that is not necessarily manifest, while everything
> else is defined as by default something that is manifest,

Everything else? How about {crida}, {xanri}, {namcu}, etc?
What do you mean by manifest?

> then there is
> an inconsistency. I've given additional reasons for why {nu} is
> inconsistent (its guaranteed non-emptiness, its unverifiability).

It would be as verifiable as {xanri}.

> Your "very generous definition for what counts as a {nu broda}" amounts
> to an inconsistency, since no other predicate has a definition of
> such generosity.

{xanri} would seem to be pretty generous too.

> The worst thing about your definition is that {lo dahi nu} and
> {lo dahinai nu} would mean the same thing. We should have no easy
> way to guarantee that we are talking about an actually happening
> event.

You would have to make the claim that the event ca'a fasnu, but
I agree with you it is not a nice definition. It is not a definition
that I like, and I don't advocate it. I only say it wouldn't be
inconsistent. It would often be counterintuitive.

Jorge