Path: utzoo!attcan!utgpu!watserv1!maytag!watdragon!violet.waterloo.edu!cpshelley
From: cpshelley@violet.waterloo.edu (cameron shelley)
Newsgroups: comp.ai.philosophy
Subject: emergent properties
Message-ID: <1990Sep29.213139.2876@watdragon.waterloo.edu>
Date: 29 Sep 90 21:31:39 GMT
Sender: daemon@watdragon.waterloo.edu (Owner of Many System Processes)
Organization: University of Waterloo
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  I have found the discussion of 'emergent' properties quite interesting
and would like to add some comments of my own.  My background is more in
computer science (NLU, say) and linguistics than in philosophy or 
physics and my discussion will no doubt reflect that.

  In semantics, people like Montague have created theories using the 
"principle of compositionality" (Frege's principle) which basically
asserts that (in the case of languages) the meaning of an utterance
can be arrived at by a finite series of manipulations on its component
parts.  These manipulations may be of arbitrary complexity, so long as
they are well formed.  This works well for analysing sentences or 
short discussions, but less well for language that relies heavily on
metaphor or other nebulous contexts: eg. "No man is an island", which
is quite trivial on the surface.  Montague proposed to get around this
by supplying extra rules (presumably with higher precedence than the
compositional ones) which would 'intercept' such idioms and language
and express their value directly, without further analysis.  At least,
this is my understanding.  Thus the problem would be solved by fiat,
much as the Russel paradox was solved by Von Neumann.  Whether metaphor
and the like can be considered examples of emergent properties of mind
or language is highly debatable since our knowledge of linguistic
"atoms" is so insecure.

  Btw, the definition of emergent property I'll try to stick to is
that of a property of a 'system' which is not provable from a complete
knowledge of the properties of its 'parts'.  The definiton of 'system'
and 'part' I will leave alone for the time being.

  Hofstadter mentions in _Goedel, Escher, Bach_ (GEB) that in 'chunking'
information, ie. in moving up a level of abstraction, some detail is
inevitably lost.  Someone (sorry I don't have the attributes here!) 
mentioned that the chemical properties of a mixture are not always
visible from the chemical properties of its components, such as the
solubility of gold.  It is, I think, possible to explain such effects
by moving down to a lower level of abstraction (or description), in 
this case say quantum electro dynamics, but then again the description
of the 'emergent' property also becomes more complex when moved to
that same level - which seems only fair.  Does the explanation of the
emergent property involve new 'emergent' properties at the new, lower
level?  I don't know the answer in this case, but I will assume that
its possible.  At this point, one can play "the chicken and the egg"
with levels of abstraction until one hits bottom - the axioms.  Are
the axioms of a mathematical system considered emergent properties of
- nothing?  Or in physical terms (correct me if I'm wrong), is the 
material universe an emergent property of the vacuum?  Damned if I 
know! :>  Mathematical axioms are just projections of our perceptions
of reality, or part of it, as are the 'laws' of physics.  But I'm
getting off topic...  The point is we ultimately run out of 'parts'.

  GEB also discusses that what we might consider information, is not
necessarily located in an easily definable place.  Examples given in
this group have been the nature of human memory in the brain, and the
number of users that can log into a system before it starts running
into difficulties.  Level of abstraction plays a part here too, ie.
what exactly is "a memory", or even "a user" to the computer system?
A memory is not a useful concept when dealing with fine details of
brain chemistry, but it is for us who live at a much higher level and
do not perceive the world (intuitively) in terms of exchange of electrons
and energy particles.  But does that mean 'memory' is or is not an 
emergent property?  The question is answerable 'yes or no', I believe,
when it is qualified as "emergent relative to what description level?"
If it is asked with reference to some 'absolute' framework, then I don't
see how it could be answered one way or the other.  

  Which brings me back (finally :>) to the issue of 'system' and 'parts'.
These two terms both refer to how we look at things.  If a car is a 
system, then can the design team be considered parts?  They are as
responsible, in a way, for the properties of the car as are the metal
pieces that physically make up its engine.  The question sounds absurd
in english since its speakers have a very noun-based view of the world
in which everything is a delimitable object or a process which affects
such objects (I am oversimplifying somewhat, but the trend is there).
Some languages (several north american indian ones for example) look 
on objects as being a 'slice' from a temporal process spanning the whole
lifetime of the 'object' they see.  In such a view, the designers of a
car could well be considered 'part' of it.  Similarly, Searle's
(in)famous chinese room problem rests heavily on the 'obviousness'
of the composition of a room, book, and person as an intelligent
system being an absurdity.  What I'm saying, in short, is that a 
candidate for an 'emergent' property may be a result of a 'part' which
we simply do not perceive as being present in a 'system', or that our
idea of 'system' is too narrow.  The effort
to eliminate this problem might ultimately require some reference to
a set of 'all parts' which is certainly not tractable and certainly
impossible in any axiomatic system I have heard of.

  My conclusion is that the idea of 'emergent' properties is inevitable
at any level of abstraction, but does not necessarily constitute
something unexplainable in principle.  On the other hand, the reduction
of all 'emergent' properties is a waste of time and, I believe, not
completely possible anyway.

  I am looking forward to some comments on this one!  Anything constructive
would be appreciated. :>


--
      Cameron Shelley        | "Armor, n.  The kind of clothing worn by a man
cpshelley@violet.waterloo.edu|  whose tailor is a blacksmith."
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 Phone (519) 885-1211 x3390  |				Ambrose Bierce