The notion of semantics in Rosen's writings

[Carlos Limarino <***>]

In an essay called 'Syntactics and semantics in
Languages' Rosen makes some assertions. A very
problematic for me is this: 

"An essential part of any language resides in its
implication structure. This comprises a system of
entailments, which generally are expressed in the
terse form P → Q. The main property of such
implications, or entailments, is that they propagate
?truth? hereditarily across them; thus if P is assumed
to be ?true? (whatever truth may be, here), then Q
must be true also. It is often supposed that such
inferential entailments are part of the syntax of the
language and do not themselves depend on any external
referents or meanings; only the truth values arise
semantically. Of course, such truth values may simply
be posited, but in either case, they come from outside
the syntax itself. We shall not make this supposition
in advance; we leave open the possibility that the
entailment structure of the language itself can change
by virtue of what the language is about?that is, that
it can depend on semantic as well as syntactic
features. This kind of possibility is denied by the
claim that semantics can always be reduced to syntax."

Then he proposes something called 'modeling relation'.
In this 'modeling relation', he says, there is
'encoding' and 'decoding' between what he calls (at
least, in the book 'Life Itself') as 'natural system'
and 'formal system'. Rosen says that a 'natural
system' has a set of 'causal entailments' and a
'formal system' has a set of 'inferential
entailments'. 
The first problem I have is with the definition of
'encoding' and 'decoding'. Rosen defines in the book
Life Itself encoding and decoding as the 'translation'
between 'formalisms'. I understand this as the idea of
translating well-formed formulas given in a formal
language to well-formed formulas of another formal
language. But, what is 'encoding' and 'decoding'
between a formal language and a 'natural system'?
Also, is not very clear to me what qualifies as a
'natural system', since Rosen defines them as systems
"in the ambience or external world". I can't
understand Rosen's point very well, so I'd pleased to
know in what exact sense" the entailment structure of
the language itself can change by virtue of what the
language is about" and if Rosen effectively is
asserting this. Are the logical constants of the
formal language of a formal logic a candidate for
"entailment structure"?

Thank you


__________________________________________________
Correo Yahoo!
Espacio para todos tus mensajes, antivirus y antispam ¡gratis! 
¡Abrí tu cuenta ya! - http://correo.yahoo.com.ar