Thursday, December 15, 2005
Communications on lattice of theories
On Wed, Dec 14, 2005 at 09:13:36PM -0500, John Sowa wrote:
...
One point I wanted to emphasize is that natural languages are far
more
complex than many people have assumed. In particular, many of the
ontologies that have been proposed can be viewed as
implementations of
Wittgenstein's first book, the _Tractatus Logico-Philosophicus_.
In his later book, the _Philosophical Investigations_, W.
criticized
the "grave errors" of his first book. I am convinced that
Wittgenstein's second book is a much sounder basis for ontology
than
his first book. In effect,
W's first book proposed one giant
"language game" represented by one giant theory -- much
like many
currently proposed ontologies.
Many of the AI systems implemented in
the 1970s and '80s could be viewed as direct implementations of
W's
first book. As I argued in
the knowledge soup paper (see below), I
believe that approach is doomed.
In W's second book, he argued for an open-ended number of language
games.
Response from Chris
Just as a matter of (for purposes here) completely irrelevant exegesis, I can't think of a shred of evidence in Tractaus for the idea that there is "one giant theory". Tractaus does contain a single, very influential theory of *meaning*, viz., the "picture" theory, according to which a sentence has meaning insofar as its internal structural corresponds in a certain way to the structure of the objects denoted by its referring terms. And his purpose was to circumscribe thereby the *limits* of language, and in particular its powerlessness for expressing and answering questions concerning what is in fact most important in life, questions of life's meaning, questions about the good and the beautiful. Thus the towering, and ultimately tragic, proposition with which Wittgenstein closes the book: "Wovon man nicht sprechen kann, darüber muß man schweigen!" (Toulmin and Janik's superb book _Wittgenstein's Vienna_, which situates the development of TLP in its broader cultural milieu, is essential reading on this point.)
It is of course true, as you note, that Wittgenstein roundly rejected the Tractaus in the Philosophical Investigations, but your characterization above suggests that his major critique consisted in rejecting the idea of "one giant 'language game', represented by one giant theory", in favor of many, as in your lattice of theories. But this is seriously misleading. For Philosophical Investigations is a rejection, not of the idea of one giant theory, but of the whole idea that meaning is representation. He would reject your lattice of theories -- all of them representational in nature -- as emphatically as a single giant theory. His phrase "language game" was meant to underscore this, as games are things people *do*; meaning, according to the Wittgenstein of Philosophical Investigations, consists not in the fact that sentences represent a (purported) objective external world, but in what they are *used* for. In Tractaus, sentences are mirrors; in Philosophical Investigations, they are tools.
Me, I think Wittgenstein pretty much got it right in Tractaus. ;-)
Chris Menzel
Comment on Chris’s viewpoint à [306]