From PhilPapers forum Philosophy of Mind:

2009-04-29
The 'Explanatory Gap'
Reply to Stevan Harnad

Hi Stevan, I appreciate your responses, esp. correlates vs. analogs in psychophysics.  Because I'm not 'pro' status, my posts may lag by 24 hours or more.  I'd unfortunately already submitted my post when you responded regarding correlates vs. analogs in psychophysics.

Please correct me if I'm wrong, but I believe the concept of 'telekinesis' is abhorrent because it suggests there are non physical phenomena which influence the comings and goings of material things.  Whether we're talking about classical or quantum phenomenon, such things as momentum, position and fields are measurable in some way.  To suggest these things might be influenced by 'feeling' seems ludicrous.  However, suggesting that momentum, position or fields can create phenomena that are not measurable by measuring the momentum, position and field is just as serious a problem as suggesting said phenomena influences those measurements.

If you don't want to accept telekinesis, then why accept the corollary which is that objectively measureable properties produce phenomena that are not objectively measurable?  Call this "materialkenesis" or m-kinesis for short if you'd like.  If you can't measure it, don't accept it.  Unfortunately, that brings us back to #1, and neither you nor I are happy about that.

Earlier you suggested that experience/qualia/feeling are measurable by the subject and reportable, but are not causal or perhaps are epiphenomenal.  Could you be so kind as to clarify this?  I'll explain what I think you mean and what I think you don't mean.  By so doing, hopefully you can clear up my confusion.

I believe this gets back to telekinesis.  You don't want experience to influence anything physical.  You don't want there to be an unmeasurable influence on any material comings and goings.  As an example, we might consider a computer being used to control some process such as the launching of a rocket.  One might say the computer has a causal influence over this process, albeit an epiphenomenal one.  Computers are made up of electric circuits, so the computer's (epiphenomenal) causal influence over the launch is dependent on those circuits.  Similarly, the circuits are made up of bits of wire, capacitors, resistors and transistors that are integrated onto a chip.  So the launch is caused by the computer is caused by the circuit is caused by the chips is caused by the transistors is caused by the molecules/atoms making up the transistors.  One might take the position that everything above the molecular level is epiphenomenal, and certainly philosophers have suggested exactly this.  But I don't think anyone is suggesting that computers, circuits or transistors are not causal.  They are all part of a causal chain from atomic and molecular interactions to rocket launch.  To conclude, I believe you're suggesting that experience is not part of that causal chain.  Experience/qualia/feeling can not play a part in any way in this causal chain.  What I don't think you're suggesting is that feelings are epiphenomenal in the same sense as the computer's causal influence is epiphenomenal on the circuits and transistors since this would put feelings into the causal chain of events.

If this is backwards, my apologies.  Now, let's suggest that the experience of the color red can be reliably measured by a person.  In contrast, a digital camera can take light and convert it to a digital pattern which can be reconverted to wavelength using just three pixels on a computer screen.  The intensity we observe from each pixel is interpreted and converted to color inside the brain.  I doubt anyone would say that the experience of color exists at any step of the process between recording the color red using the camera and the reproducing of the color at a computer screen.  However, let's say we had a device which could reliably measure the experience of red.  A human is just such a device if experience reliably correlates to function/behavior.  The measurement is entirely internal, but let's assume for now that this internal measurement is reliable.

Now, if this internal measurement is reliable, then let's assume we can similarly produce this experience computationally.  Let's assume our computer's transistors can produce this reliable correlation and report dutifully the experience has been accomplished.  If this is possible, then that computer is no different in principal from a multitester.  It has physically measured the phenomenon in question and produced a physical report.  This much is m-kinesis. 

If the measurement of the experience is reliable, then that measurement can be (must be) converted to a physical signal so that it is reportable, else it is not reliable.  So if the measurement of experience is reliably reported, then something can be done with that signal.  The signal can be interjected into a causal chain as suggested by the rocket launching example above.  We can have an if/then statement in our computer which says, If Xperience = RED then "SCRUB LAUNCH".  In this way, qualia/experience/feeling is interjected into the causal chain. 

Unless I've screwed up somewhere, which is entirely possible, the bottom line is that experience/feeling can be a part of the causal chain if it is internally measurable (subjectively measurable) and as long as that measurement is reliable. 

One might still claim this influence is epiphenomenal as I've defined epiphenomenal above using the rocket launch example.  If it is epiphenomenal, then we have a slightly different problem to resolve.  The thing about this measuring instrument is that it can essentially measure the entire phase space of some portion of a system, and for it to do this, the system must be non separable.  Computers are separable however.  We can explain everything a computer does by examining the function of each transistor and circuit.  The experience for a computer  therefore is merely functing.  Experience can not be proven to reliably correlate inside a computer, and in fact, experience is never needed to explain anything a computer does.