On Mon, Apr 11, 2005 at 10:41:53PM +1000, Stathis Papaioannou wrote:
> It may be the case that quantum indeterminacy adds a random element which 
> contributes to our experience of free will, but you are dismissing the 
> other theoretical possibility, which is that our brains are vastly, 
> chaotically and perhaps even  intractably complex, but nonetheless 
> completely deterministic machines. We would then still believe that we had 
> "free will" , even though in reality we are all blindly following a 
> predetermined script. How could we possibly know that this is not what is 
> in fact happening?
> --Stathis Papaioannou

I think this situation is essentially hypothetical. No machine is
completely deterministic - computers are designed to be as
deterministic as possible, but still suffer bit errors through
chance. Human brains, however, strongly appear to be tuned to amplify
noise generated at the synaptic level to effect system level. (Fractal
structures in brainwave patterns, and the like).

More important I think is to ask what is consciousness and free-will
for in an evolutionary sense. The theory that resonates most with me
in this context is Machiavellian Intelligence theory, that human's big
brains evolved to allow individuals to survive and prosper in a human
society. To do this it become crucial to predict what other members in
the society are going to do in response to your actions. Because this
is such an advantage, it is also an advantage not to be too
predictable yourself.

This all has several consequences. It is possible, as you say, to
generate behaviour indistinguishable from randomness via deterministic
processes, however this is either computationally very expensive, or
relies on keeping the exact algorithm secret. Remember in human
societies, you opponents have access to the same computational capacity
you have (possibly more), and even parts of any algorithm you might
have if its genetically encoded. It seems more likely that brains will
tap into exploiting randomness at the synaptic level - this will also
work if you're a fairly dumb herbivore trying to outsmart an
intelligent predator.

Another consequence of MI is that the most economical way of modelling
another human's behaviour is to study your own. Hence it is useful to
have a theory of the mind => self awareness as a useful evolutionary
feature. However, a theory of the mind is only useful if it can
predict what the other organism does - hence the mind must be in
control of the actions, not just along for the ride.

Now for the age-old corny question of whether free-will is an illusion
or not. Mind is an emergent property - it is not to found among the
neurons making up the brain, however it is a useful predictive
model. This makes it emergent in just the same way as a glider is an
emergent property in the Game of Life. Just as the mind is emergent,
so is free-will, for the same reason. And just as you can argue (if
you want to) that GoL gliders are an illusion, you can argues that
mind and free-will is also an illusion - this does not preclude them
as a useful modeling concept for the organism. My personal preference
is to label these emergent concepts as real (when they're useful that
is), but it is a matter of taste. As an aside, I always considered the
high school explanation that centrifugal force was fictitious with


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A/Prof Russell Standish                  Phone 8308 3119 (mobile)
Mathematics                                    0425 253119 (")
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