From: Mitchell Porter (mitchtemporarily@hotmail.com)
Date: Mon Jul 25 2005 - 11:08:03 MDT
I hope I finish this reply before the thread gets killed, unlike last time.
Let us start with some epistemological basics. In contemporary philosophy of
mind, qualia are often discussed as if they were a sort of afterthought to
the material universe, the debate being over the alleged necessity or even
just the reasonableness of positing such extra entities.
However, epistemologically, qualia are the starting point, and the material
universe is the thing posited. For example, my present visual sensory
manifold consists of a continuum of colored forms, which I interpret as
objects in three-dimensional space, and about which I make many further
assumptions. Those assumptions may or may not be correct, but there is no
point in denying the existence of the colored forms themselves, at least if
I am interested in reality.
It should be equally obvious that a patch of color cannot be the same thing
as a configuration of colorless particles in space. I ask you to conceive of
point particles possessing a specified mass, a specified charge, a specified
location, and no other properties. Sprinkle them about in space as you will,
you will not create a 'sensation of color'. Equip them with a certain
dynamics, and you may be able to construct an 'environment with properties'
and a 'stimulus classifier'; name some of those environmental properties
'colors' and some of the classifier's states 'sensations of color', and you
may be able to mimic the apparent causal relations between our environment
and our sensations of color; but the possible world you have thereby
specified does not contain sensations of color as we know them, and
therefore cannot be the world we are inhabiting.
In fact, the class of possible worlds presently contemplated in fundamental
physics - that is, those taken seriously as candidate descriptions of the
world we are inhabiting - is extrapolated from an ontological base
originally constructed by exclusion of so-called 'secondary properties' such
as color and pitch from consideration. Theoretical understanding of the
residual properties (notably quantity, spatial location, and process) has
been extensively developed (under the formal titles of algebra, geometry,
and dynamics), and present physical theory relies almost exclusively on
these disciplines for its concepts. As a result, we are rather good at
describing and predicting the motions of things in space, but we are at a
loss almost everywhere else.
This would be a purely philosophical conundrum were it not for information
technology, which in its microphysical particulars is a fruit of that same
success in understanding matter in motion. We are faced, not just with a
self-denying sensibility which wishes to assert that colorless matter in
motion is all that exists (in which case the secondary properties - the
qualia - are either mysteriously identical with certain unspecified
conjunctive properties of large numbers of these particles, or even more
mysteriously do not exist at all), but with the construction in the world we
are inhabiting of imitative mechanisms like the one in the thought
experiment. By 'imitative' I do not mean 'capable only of behaviors already
performed by human beings'; I mean 'constructed in imitation of the apparent
mechanisms of human beings'.
My attitude to the problems of consciousness and the problems of artificial
intelligence as discussed on this list is as follows. Mathematical physics,
as we know it, is both an apex and a dead end. No amount of quantitative
predictive progress through better model-building is going to explain
consciousness, because the models in question exclude certain aspects of
reality *by construction*. If you like, physical theory and contemporary
technology illustrate how far you can go while operating in a mode of
consciousness based on such exclusion. However, if we wish to actually
understand ourselves, we need to readmit the 'secondary properties' to
attention, and in fact everything in phenomenology that has been passed over
as difficult to physicalize; and we are going to have to exhibit some
philosophical imagination when it comes to ontology. Meanwhile, we have
managed to automate the imitation of cognition, raising the possibility that
we will create behaviorally superintelligent systems before we truly
understand what awareness is. Dealing with this situation is a practical
problem, and I respect the design philosophies discussed here as approaches
to that problem, but I very definitely dissociate them from the physicalist
theories of mind with which they tend to come packaged. To what extent AI
theorists need to think about post-physicalist ontology is an open question;
I suspect that there is room for division of labor, with some working on
problems confined to the domain of algebraically/geometrically/dynamically
describable phenomena, and others really looking at the complicated
interplay between full-spectrum phenomenology, possible ontologies, and
possible mind-like entities. It does seem unlikely that an AI designed
solely to operate in that first domain will be much help with the broader
problems, except negatively, by inadvertently demonstrating its limitations.
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