Apologizing in advance...

[Richard Rohwer]

A CONNECTIONIST THEORY OF ONTOLOGY
Richard Rohwer
3 May 1989

	OK, all you philosophical bullshitters!  Here's the definitive
theory on life, the universe, and connectionism.

	Let's start by trashing the silly idea that computer simulations
of thunderstorms just aren't wet enough.  Well allright, they're not wet
enough on the Met's wimpy CRAYs.  But those CRAYs are only simulating
part of the thunderstorm experience.  They cut up the storm into a
gridwork of little fluid elements, each of which is just a bunch of
numbers.  As the simulated thunderstorm rages along, the numbers in the
fluid elements change this way and that according to some approximated
physical laws.  In order to save on computational expense, only part of
the structure of a thunderstorm is simulated-- the structure which
exists on scales large compared to the grid size.  Of course that
simulation isn't wet.  My claim is that a more complete simulation is
necessary.

	You will probably object that even if I simulate every subatomic
particle in every detail, then it's still just a bunch of numbers and it
doesn't feel wet.  That's because you probably think I mean to leave the
observer out of the simulation.  Well I don't.  Of course the simulation
doesn't seem wet to the programmer looking at all the reams of numbers. 
The interaction between the storm and the observer is quite important in
the business of making the observer wet, so it's no good leaving that
out of the simulation.  The programmer cannot be made wet by the
simulated thunderstorm any more readily than an observer watching an
Amazonian thunderstorm through a telescope in the Martian desert.  But
that doesn't mean the jungle's inhabitants keep dry.

	So we simulate, atom-by-atom, an observer standing in the
simulated thunderstorm.  Perhaps now you object that without actually
being the simulated observer, we cannot be sure that the simulated
observer is the least bit conscious and feels anything.  In that case,
you are probably one of those silly solipsists, in which case I write
you off as a hopeless case.  True it is, I must assume at this juncture
that given enough machinery of brain, mind will be present.  And I
assume, furthermore, that the formal connectionist structure of the
brain's machinery is all that is required to support a mind; that it's
the program running on the pattern of connections that does the trick,
and it really doesn't matter what the machinery is made of.  In
particular, it really doesn't matter that the machinery happens to be
quite a lot of silicon chips constituting a really groovy computer. 

	So there you have it.  Given just a few innocent assumptions
(which can be solidly proven using a few pints of real ale) we have
established that, when set up properly, simulated thunderstorms really
are wet.  But we can push this a little further.  What's the purpose of
this super-duper computer that runs the simulation?  It's just there to
provide an instantiation of a formal mathematical system in which the
simulation is expressed.  The simulation doesn't really need a physical
device on which to be simulated; it only needs the formal mathematical
system.  And that's cheap.  It exists as a mathematical tautology, just
like any formal system.  So we can throw away the physical computer and
still keep the thunderstorm together with all its wetness.  Physics can
be built out of mathematics using this connectionist theory of ontology:
To get the machinery required to support a mind, it's enough for a 
connectionist mathematical formalism (augmented with a physics formalism)
to be a theoretical possibility.

	Have another pint.  Now consider two simulations of the same
thunderstorm-observer system running on different machines.  Are these
different systems?  Certainly not.  The machines serve as a
representation/communication medium between the world of the simulated
thunderstorm and the world of our own subjective experience, much as
coordinates serve to represent vectors.  The simulated thunderstorm
exists for the simulated observer regardless of whether we bother to
simulate it, rather like a vector exists regardless of whether we give
it coordinates.  But we cannot learn much about the simulated system
without using a simulator, much as we cannot write down a vector without
using coordinates.  And the simulated system is the same system
regardless of which, or how many simulators we use to "view" it, much as
a vector is independent of the coordinate system or systems used to
represent it.  

	So any simulatable world with simulatable observers exists
physically for those observers just as the world for which we are
observers exists physically for us.  So there must be quite a lot of
physical worlds out there, including many which are quite like our own,
except for some fine, distinguishing details.  So how similar do these
other worlds have to be to our own in order for us to be able to
physically observe them, just as we physically observe our own world?
Surely not every minute detail is important.  In some sense, we must be
partially aware of worlds which are very similar to ours; minds which
are very similar to ours.  But then that makes our world more like an
ensemble of similar worlds of which we are partially aware.  For my
money, this is what quantum interference is all about.  It behooves me
to derive the quantitative quantum formalism from this point of view but
alas, (due to a looming hangover) I can only support the idea with some
qualitative points: a) Quantum theory is at pains not to ascribe
physical reality to anything which has not been carefully observed, and
b) In its purest form (ie., without collapse of the wavefunction),
quantum measurement theory is a many-worlds theory. 


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