David Nyman wrote:
> 2009/9/14 Brent Meeker <meeke...@dslextreme.com>:
>>> Yes, of course I know it's *implicitly* physical, that's the problem.
>>> The point is that evaluating CTM as a physical theory of mind
>>> necessitates making the relation between experience and process
>>> *explicitly* physical, and actually attempting this inevitably results
>>> in a failure to discover any consistent association between specific
>>> physics and specific experience.
>> That seems like a category mistake.  You're asking for and explicitly 
>> physical relation
>> between a computation and a physical process.  But a computation isn't 
>> physical; the
>> relation has to relate something non-physical to the physical - so obviously 
>> it relates
>> the non-physical things like potential action in a context or evolutionary 
>> function to the
>> physical process.
>>> This is not merely unfortunate, it
>>> is a direct consequence of the arbitrariness of physical
>>> implementation central to the hypothesis.
>> I don't see the problem.  There are arbitrarily many computations of the 
>> same function too.
> I'm having a really hard time comprehending why we're at such
> cross-purposes here.  I have no difficulty with the formal definition
> of a computation, its multiple realisations, or with your criterion of
> relevance to an external context.  However none of this is remotely
> relevant to what's at issue with respect to the status of CTM as a
> physical theory of *phenomenal experience*, as opposed to observed
> *behaviour*, which AFAICS is all you are referring to above.
> Let me put it like this.  In any physical account of a particular
> phenomenon, some physical events will be relevant, and some
> irrelevant.  I gave the example of differently fuelled journeys - I'm
> sure you can think of a dozen equally good or better examples.  In any
> of these examples you would seek - and should at least in principle be
> able - to explain what is physically directly relevant to the outcome,
> what is irrelevant (in the sense of merely generally supportive of)
> the outcome, and how precisely this demarcation is justified in
> explicit physical terms.  In each case, the line of demarcation would
> be at the point where some common physical outcome can be identified
> as emerging from disparate underlying processes
> Now let's consider CTM on the same terms.  We seek to explain an
> outcome - an experience - that will emerge at some point of
> demarcation of relevant and irrelevant physical processes.  To this
> end let us attempt to test the postulates of CTM against physical
> criteria independent of the hypothesis.  In fact we have no way of
> demarcating any homogeneous physical emergents other than at the
> boundaries of the system, 

But the boundaries are moveable.  If we ask does traveling from A to B by this 
produce the same experience as by another path the firs thing we do is move the 
in.  Do both paths go thru C?  thru D? and E? and...  So then question then 
becomes how 
close together do the intermediate points have to be to constitute the "same" 
An interesting question.  We might investigate it empirically by noting how 
closely the 
brain processes during one experience of X are similar to another experience of 
X - of 
course that brings out that to compare two experiences really means to compare 
one to the 
memory of the other or the memories of both.

>because the hypothesis rules this out, so
> already this makes the case quite dissimilar to any other, but let
> this pass for the moment.  We will consider only the putative
> homogeneous experiential correlate of the heterogeneous physical
> computational processes.  What can we employ as the physical criteria
> for its emergence?  That the relevant physical processes should be
> present.  What can we use to identify such processes and establish
> their relevance in terms of any given realisation?  Answer: only the
> formal premises of CTM.  Anything else?  Not a thing.
> Computational theory in purely behavioural guise meets the criterion
> of equivalence not through homogeneity of physical realisation but in
> consistency of relation with an environment, as you imply.  By
> contrast, any internal physical processes associated with a
> computational theory of homogeneous experience can only be identified
> and justified in terms of its own formal internal premises.  Hence any
> physical justification deployed for this purpose in terms of any
> specific realisation must be completely circular.  We are not supposed
> to assume our conclusions in our premises, and the inevitable result
> of so doing is to fail to make any substantive physical commitments
> independent of the formal presuppositions of the hypothesis itself.
> It is entirely a consequence of this that reductios such as MGA are
> able to do their work, because this physical vacuity is what permits
> grossly implausible realisations to be considered valid by the posits
> of the theory.  This is QED AFAICS.  How specifically, and at what
> point of the argument, would you disagree?

I disagree the that reductios prove anything except that the context may have 
to be 
arbitrarily large.


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