Respectfully,
Don Mikulecky
Bruce Edmonds wrote:
> Normon wrote:
> > So perhaps we ought not to try so hard to classify all macro
> > physical objects as "either" machines "or" organisms. These
> > divisions are questions of logical typing. They are also
> > relative to both context and level.
>
> 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