Re: Logical?

And Rosta <a-rosta@...> wrote:

>Mike:
>> A conlang is logical if all well-formed statements (though
>> not questions and commands) are logical expressions.
>
>I don't think you need to exclude questions and commands. Rather,
>you need to enrich the vocabulary of logical expressions with a
>set of illocutionary operators.
In other words, a command like "Have a slice as pizza" could
be interpreted as "I am inviting you to have a slice a pizza".
The latter could be true or false depending on whether the
speaker was making a sincere invitation.  Is this what you
have in mind?  If so, then *I* agree with you that every
sentence in a language can be made logical.  I made the
weaker claim in anticipation that someone might not accept
that view.



>> An expression is logical if it evaluates to either true or
>> false, but not both.  In plainer language, every expression
>> in a loglang should *unambiguously* convey to the listener
>> an idea about the way the world would have to be in order
>> for the expression to be true.
>
>This is too high and too inappropriate demand. For example,
>the truth of a sentence containing a referential expression
>cannot be determined until the referent is determined, but
>the language itself does not determine the referent; when
>I say "I saw him/the man score", there is nothing in the
>sentence -- in the linguistically encoded/determined meaning
>-- that tells you "him/the man" refers to David Beckham.
>Rather, the reference is determined pragmatically, and the
>sentence encodes an *incomplete/underspecified* logical
>formula.
This gave me some food for thought.  There are two
possibilities here.

If "him/the man" is an anaphor for David Beckham, previously
established in discourse, then we have a bound variable, and
the sentence is totally logical.  I know this is not what
you had in mind, but I mention it to be thorough.

If "him/the man" is being newly introduced into the discourse,
we have what *appears* to be a free variable.  However,
I think this only holds if one insists there is no discernable
existential proposition inherent in the statement.  I am
inclined to argue that there is.  What we have is:

Ex [(x is a man) & (I saw x score)]

Whether or not the speaker has a much more specific referent
in mind than a simple existential does not, IMO, degrade
the logicality of the statement as given.  The speaker might
simply choose not to mention that data, just as he may
choose not to mention what color shirt he was wearing.
IMO, the sentence has provided enough information to convey
to the listener an *idea* about the way the world would
have to be in order for the expression to be true, or false.

Incidentally, one might claim a non-veridical interpretation
for "the man" (as Lojban might); nevertheless, the sentence
implies that a score took place, and that "I" saw the x1 that
did it;  IMO that is still satisfactory as a logical statement.
BTW, I think that Lojban descriptors are its greatest feature;
they turn examples like the one you give into explicitly
logical propositions.



>> All natural languages are logical for the most part, but not
>> rigorously.  A language designed for logicality will pay
>> careful attention to the logical implications of its
>> constructions and will attempt to make the rules for logical
>> evaluation straightforward and consistent.
>
>"will tend to attempt" would be better.
>
>> In order to be logical, a language is required to have
>> an unambiguous syntax (i.e. all phrases are bound), an
>> unambiguous lexicon (i.e. no homonyms are allowed; the
>> morphology self-segregates), and unambiguous pragmatics
>> (i.e. prescribed literalism--the speaker must say what
>> he means; words are interpreted at face value).
>
>Self-segreting morphology is not necessarily a requirement;
>nonselfsegregating morphology will not necessarily result
>in lexical ambuity, and nonselfsegregating words result
>only in holistic ambiguity, not in specifically syntactic
>ambiguity.
True.  Of course, a designer ignores self-segregation at
his loglang's risk.  As language grows, ambiguity will
almost certainly eventually creep in.



>As for 'unambiguous pragmatics', much as I attribute it to
>Livagian culture, it would be a cultural rather than a
>strictly linguistic phenomenon, since a fully logical
>language may nevertheless be used illogically.
On reflection, I might have overstated the need for unambiguous
pragmatics.  To use a not-so-great example, if the English
phrase "kick the bucket" is so commonplace for "die" that
it is essentially rendered a lexical entry, then of course
the speaker and listener will have an understanding and
logicality is served.  This seems perilous though.  How
do you express veridically when a bucket really is kicked?


Regards

---   Mike

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