I agree. A strict Artistotelian dichotmy is not always helpful - of
course, it depends what how you want to *use* the classification.
Consider some examples:
1. A CAR
A car is clearly both a machine and a complex system, although in
slightly different senses. Can the complex car and the simple car be
associated - clearly yes, they may refer to the same object. This does
not mean that the car-as-complex and the car-as-simple are the same,
merely that they are related.
In Artistotelian (i.e. absolute terms) the car `is' a complex system
(being an object of the natural world). However it is designed to act
as a machine - and it does (for a period of time and to a reasonable
approximation).
There is no stronger test than real interaction with the world - the car
(within certain bounds) is a machine. That is what it is to be a
machine, nothing more.
So what is one saying when one says "A car is not a machine"? One is
saying that our picture of the car as a machine is necessarily a partial
model of it - it only holds within certain bounds. But this is true of
*all* knowledge, including statements like "an object either has
property A or it does not".
2. THE BOUNDED HALTING PROBLEM
Consider the problem, given a natural number n, the task of deciding
whether a Turing Machine of index less than n and an input of size less
than n will halt. Given any particular n this is decidable, i.e. there
exists a purely formal procedure for deciding this fact. However there
is no uniform procedure for any n (otherwise we could solve the general
halting problem).
The general halting problem is a purely formal one - yet there is no
combination of the bounded sub-views (the procedures for deciding the
bounded halting problem for each n) into the total view (a procedure for
solveing the general halting problem). Hence according to Don's
criteria it is a complex system - complexity (in Don's sense) streaches
into the purely formal. It does not only occur in the natural world.
CONCLUSION/MORAL
The simple/complex dichotomy itself is (inevitably) a partial view of
the world. It is necessarily not the whole story - in a sense it is a
fiction. Its purpose is to point out that the reductionist approach has
its limitations. These absolute `fictions' have thier uses (as do other
fictions, e.g.: absolute time, reductionism, etc.), but they also have
their limitations.
Yet they are more than fictions, for what we call `knowledge' consists
of nothing more than them.
Regards.
--------------------------------------------------
Bruce Edmonds,
Centre for Policy Modelling,
Manchester Metropolitan University, Aytoun Bldg.,
Aytoun St., Manchester, M1 3GH. UK.
Tel: +44 161 247 6479 Fax: +44 161 247 6802
http://bruce.edmonds.name