* Friday, 2011-10-14 at 11:39 +0100 - And Rosta <and.rosta@gmail.com>:
> Martin Bays, On 13/10/2011 05:33:
> > To take a simple example: when the {lo} is read generically, what does
> > {lo remna cu prami ri} mean? There are two obvious possibilities
> > - "humans love humans" (both generic) and "humans love themselves". The
> > first is natural only if we admit kinds.
>
> The debate may have moved on, but back in the day, I'd have understood
> it to mean "the human loves themself" (or, equivalently, "the human
> loves the human", just as "John loves himself" and "John loves John"
> are equivalent in logic or Lojban), i.e. a reading in which the two
> obvious possibilities you mention are in fact nondistinct (because
> there's only one human). It's true that, given that "the human loves
> themself", one is unsure whether one should infer that "humans loves
> humans" or that "humans love themselves", but that is a metaphysical
> matter rather than a linguistic one, and hence not something for
> Lojban or Lojbanology to address.
So this seems to coincide with my understanding of xorxes' approach.
Kinds are possible elements of our domain; whether a kind satisfies
a predicate is often eventually determined by the predicates satisfied
by the corresponding mundane individuals, but what that relation is
varies from predicate to predicate, and is considered part of the
lexicon.
I agree that this is internally consistent, but I remain averse to it
for some reasons I'll try to (re)summarise:
(i) Although we can leave it to the lexicon in the first instance, the
fact remains that in natural languages kind predication often resolves
to existential or generic predication over corresponding mundane
individuals. Presumably the same would hold for kinds in lojban. But
once we perform this resolution to the level of mundanes, we find that
different interpretations of {lo} resolve to different logical forms.
For example, {na ku lo cinfo cu zvati lo mi purdi} has at least the two
following meanings in terms of actual lions:
1. {lo cinfo} is interpreted as a plurality of mundane lions, giving
roughly:
For L some (contextually relevant) lions: \not in(L, my garden)
(which probably means that there exists a lion among L which is not in
my garden)
2. {lo cinfo} is interpreted as the kind Lions, giving
\not in(Lions, my garden)
which is then resolved existentially, giving
\not \exists l:lion(l). in(l, my garden) .
So subtleties aside, we have a straightforward ambiguity between
\exists l:lion(l). \not in(l, my garden)
and
\not \exists l:lion(l). in(l, my garden) .
This seems toljbo to me.
Worse, we have no obvious way to disambiguate to case 1 (with its
subtleties included).
(ii) kinds and mundanes intefere when they are both in the universe, in
a way they don't in natural languages. That's because we refer to
individuals by their properties rather than having nouns, so if
brodakind brodas then, according to the usual rules, {su'o broda} and
{da poi broda} can pick up brodakind. One fix for this is to have the
universe snap to one which excludes mundane brodas when we want to talk
about brodakind - but that's so dramatically inconsistent with the kind
of semantics I'd expect a logical language to have that I have trouble
even taking it seriously, still less imagining how it would work.
An alternative is simply to declare that these constructions *don't*
pick up kinds; but this doesn't smell all that much less like a hack
than the domain-switching approach, and it does block direct
translations of natural language constructions like "there are two
whales in this sea - the killer whale and the hump-backed whale", or
xorxes' "humans have two legs - the right leg and the left leg".
(iii) I don't believe that it's obvious from the gimste or dictionary
efforts what the meanings of selbri are when applied to kinds. For
example, I think xorxes claimed that when {nelci} has a kind in x2, it's
gives a pure-kind predication like that of the english "I like dogs",
and never has a generic or existential meaning. Is this information
really something you can glean from the gimste definition of {nelci}?
> > (For nastier a example, consider the apparently classic {ro te cange poi
> > ponse lo xasli cu darxi ri}... although I'd be happy simply considering
> > this to be meaningless)
>
> Do you mean the Lojban is meaningless, because of the inadequacy of
> the rules for identifying and interpreting the antecedent of {ri} (in
> which case I'm sure you're right)?
I did mean that.
(Although I realised that there is probably a mistake in the lojban
there - isn't what I wrote equivalent to {ro da poi te cange poi ponse
lo xaslu cu darxi da}? Anyway, replace with {goi ko'a} as required)
> The proposition intended by donkey sentences is easy to grasp, and
> pretty commonplace, but hard to formulate in ordinary logic; a logical
> language should find a way to render the proposition into logic and
> express it succinctly.
Yes.
Martin
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