On 14/10/2015 22:10, And Rosta wrote:
> On 14 Oct 2015 15:25, J├Ârg Rhiemeier wrote:
>> The recent discussions of loglangs (as a tangent of the
>> (p)aaS thread) has raised a question in me.

I was thinking along similar lines as that thread neared its
end    :)

>> I have for long been of the opinion that loglangs are
>> beside the point because language and formal logic
>> serve "different purposes".

While natural language and formal logic may serve different
purposes, I don't think that in itself invalidates loglang
experiments.  In so far as they achieve or fail to achieve
their objectives, or have to be modified to be humanly
usable, they may give some insight into the way language works.

But I was left wondering both about their exact purpose and,
indeed, the definition of them.  I said in one of my emails
in that thread that my definition of loglang was probably
too narrow.

>> I used to say that the purpose of formal logic was to
>> prove or disprove assertions, but I have been
>> criticized for that here as being "too narrow".

To prove or disprove propositions was the purpose of
Aristotelian logic.  But, as I observed in an earlier email,
formal logic has moved on over the two and half thousand
centuries since Aristotle.  Mark gave a brief and rough
outline of some of these developments.

>> So, it is upon you: what is (or are) the purpose(s) of
>>  formal logic, in your eyes?  And how does language
>> benefit from designing a logical language?  (And, of
>> course, to which degree do such loglangs as Loglan or
>> Lojban actually implement formal logic?)

I'll pass on the first question.

As regards the second question, those who still pursue the 
centuries of goal of finding the "perfect language" will 
surely find modern logic formalism tools they would wish to 
use.  And suggested that James Cooke Brown was in fact in 
pursuit of just that language and that the Sapir-Worf thing 
was an afterthought.  He may well be right.   That is 
possibly still the pursuit of some loglangers.

(Umberto Eco's book "The Search for the Perfect Language" 
gives an interesting history of the pursuit over the centuries)

> I think your question implies a perhaps off-beam
> understanding of what loglangs are. Tho loglangs are
> described as "based on formal logic", that's really just
>  a quick and dirty approximation, and is needlessly vague
>  as a definition.

But not IMO nearly as vague as defining a loglang as a 
"logical language."  Many an auxlang enthusiast has claimed 
that her/his chosen auxlang is 'perfectly logical'.  When I 
was at school long years ago, our headmaster used to bang on 
about Latin being a logical language; I have seen that claim 
made for French - and I have not the slightest doubt that 
many have made similar claims about other natlangs.    :-)

> A loglang, in a definition that I use explicitly and that
> most loglangers use implicitly even if not fully aware of
> it, is a language that unambiguously encodes
> predicate--argument structure of unlimited complexity.


> Natural languages encode PASs of limited complexity and
> do it ambiguously;

To do unambiguously what natlangs do with ambiguity - this 
seems to smack of the search for the perfect language. 
Though would a language in which ambiguity is impossible 
really be a perfect language for us humans?

> natlang syntactic structure is in part
> a PAS (or representation thereof). So the value of a
> loglang is that it encodes thought with greater fidelity
> than natlangs do. There are thoughts that a loglang can
> encode fully and unambiguously that natlangs can encode
> only partially and ambiguously.

But, in fact, do any existing loglangs encode thoughts fully 
and unambiguously?  I think not.

Also are human thought themselves ever fully formed and 
unambiguous?  I somehow doubt this.  But, once more, I say 
that the aim to encode fully and unambiguously what natlangs 
do imperfectly and ambiguously is IMO the search for the 
perfect language.

> I haven't answered your question about the purposes of
> formal logic, because the answer probably isn't relevant
>  to loglangs. Another question one might pertinently ask
>  is what value logic has for linguistics.

I would say that it may give some insight into the workings 
of human language and that loglang _experiments_ may help in 
this regard.

Um - I must return to my Glossopoeia page and redefine 
'loglang', I think.  but it will have to wait as I am 
actually in the process of updating stuff on Britainese   ;)

"Ein Kopf, der auf seine eigenen Kosten denkt,
wird immer Eingriffe in die Sprache thun."
[J.G. Hamann, 1760]
"A mind that thinks at its own expense
will always interfere with language".