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Re: [ontolog-forum] Wittgenstein and the pictures

To: <ontolog-forum@xxxxxxxxxxxxxxxx>
From: "Sean Barker" <sean.barker@xxxxxxxxxxxxx>
Date: Tue, 5 Aug 2008 17:28:14 +0100
Message-id: <000501c8f718$436298b0$0100a8c0@PackardDesk>
 The way I was taught Wittgenstein was that the Philosophical Investigations 
were a repudiation of Tractatus, and particularly of the idea that language 
<b>pictures</b> the world, to replace it by the idea that language is what 
we use to talk to each other and is founded on the "forms of life" we engage 
in. The opening section of Investigations contrasts a passage where St 
Augustine describes learning the names of  things he naturally recognises 
with a story about buying five red apples. In the latter - which is not 
about Natural Language Processing, what ever Pat Hayes says - he explicitly 
denies the need for pictures in the head. The remainder of the 
Investigations can been seen as a series of therapies aimed to wean us off 
the "pictures in the head" model of language.    (01)

 IMO the "pictures in the head" theory has its roots in Plato's theory of 
forms. From the information processing view, its paradigmatic algorithm is 
is pattern recognition, in which a signal produces a response in a matched 
filter (the pattern recogniser) which fires when the convolution of signal 
and filter crosses a pre-set threshold. The temptation of "pictures in the 
head" arises from the way our brain presents patterns ready-recognised to 
our conscious, so that when I look out of my window at an arrangement of 
red, white and black, I see a house, with no need for further deliberate 
investigation.    (02)

 In contrast, the paradigmatic algorithm for language is classification. I 
have a collection of arbitrary symbols (words) whose forms in no way relate 
to their usage - so "Kangaroo" might equally mean "Go Away" as naming a 
hopping animal. In using a language to name something, I use classification 
criteria that choose between alternative categories (and their names). For 
example, I would use the term "bird" of an animal which had feathers and 
walked on two legs.    (03)

 There remains a difficult problem of relating pattern recognition to 
classification (i.e. I have no idea what the answer is). If there were a 
fixed set of distinct patterns, then there would be no problem (and, for 
example, machine vision would have been solved long ago). However, that 
would also imply that there are a fixed set of "forms of life". The problem 
of industrial data exchange is that local organizations evolve their own 
vocabularies  according to their peculiar business processes, so that 
information sharing between companies is treacherous. The differences in 
systems of military ranks between services and countries also exhibits the 
same problem. (And, by implication, ontologies based on general language 
usage provide a poor guide to the problems of developing ontologies precise 
enough interoperation between professional organizations.)    (04)

 I note in this forum a recurring argument between on one hand the "one 
upper ontology"/"finite set of basic concepts" school and the "no single 
ontology" school. That is, in terms of the above, the "pattern recognition" 
and the "classification" schools of meaning. Since ontology languages seem 
oriented to supporting classification, it seems the former are confused.    (05)

Sean Barker
Bristol     (06)

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