Saturday, November 6, 2010

Hume and the End of the Representation Problem

A Crisis in Representation

David Hume faced a crisis of representation in the relationships between the mental and physical world.  It is fundamentally the same crisis which humanity has been trying to solve since antiquity.  Operations occur within the head of every human, and these operations differ slightly, at any given time, from the operations occurring within another human’s mind.  This means that human experience differs from person to person.  These mental contents are different and belong respectively to each and every person living on this plane.  Also in concurrent existing is some type of world which is in some way different or separate from the perception of the human mind.  This physical world is something of substance, that is tangible and in which all people exist.  The representation problem, as a crisis of rationality, begs the question of how mental entities, ideas, or experiences of the mind represent the physical objects which they are attempting to be ideas of. 
Philosophers have tried to explain representation in many ways.  Until Hume, they tried to reduce the physical to the mental, or the mental to the physical, or allow both to exist independently.  Hume takes a completely different angle in solving the representation problem.  He steps out of the box as no philosopher had done thus far.  Instead of even getting at a solution, Hume attacks the problem.  He simply states that we, as humans, lack the ability to even pose the question of representation because of our limited experience.  Hume uses an interesting example to explain himself, involving a brain in a vat.

Am I Just a Brain in a Vat?

Hume has us imagine a brain floating in a vat of fluid, hooked up to various input sensors and contraptions.  The equipment connected to the brain uses electromagnetic pulses to create feelings and sensations within the brain that are exactly the same as a human being would get while experiencing real life outside of the vat.  When a person eats a Snickers bar, many sensations are picked up by extensions of the cerebrospinal system and transformed into chemical signals which the brain regards as feeling and experience.  The brain in the vat is fed only the experience of eating a Snickers bar and cannot tell the difference because the signals given to it are identical to those that a real person would get while having a real experience.  As a result, the brain in the vat never has a true experience; it is only artificially given the feelings that the having of an experience would produce.

Hume then has us envision the brain thinking abstractly about its own existence.  The brain asks itself the question, “Am I just a brain in a vat?” and then proceeds to answer itself.  Before it can answer, however, Hume jumps in and questions the brain’s ability to ask this.  And before Hume can propose his philosophy, one must understand the difference between ideas and impressions.
Hume’s impressions are very similar to John Locke’s simple ideas of sensation.  An impression is a single episode of feeling, seeing, or otherwise experiencing.  If a person were to turn on a light switch, see a chair, turn off the light switch, then turn it on again and see the chair again, they would have had two separate impressions of the chair.  An impression is one particular incident when the chair is seen.  An idea is something which is based upon an impression.  For every idea, there exists an antecedent, or preceding, impression.  So, under Hume’s philosophy, all ideas come from impressions.  In order to have an idea, one must first have an impression which the idea resembles.  These ideas differ from their impressions based on something called force and vivacity.  In short, this means that a person can tell the difference between seeing a chair, anticipating seeing a chair, and remembering a chair.  Seeing the chair would be an impression, while thoughts about that chair are ideas based upon that impression.

So, if the brain in the vat attempts to ask the question of whether it is really a brain in a vat, it is limited in what it can actually ask..  A brain in a vat cannot travel outside of its own experience, so the idea of a brain in a vat to the brain in the vat will not be the same as an actual brain in an actual vat.  In order to have an idea of a real brain in a real vat, an impression of it must be experienced first, as impressions are based on ideas.  Since all the brain has experienced are electrochemical signals, it can only imagine an electrochemical brain in an electrochemical vat, not the real thing.  A conscious being outside of the brain’s experience, such as a scientist in the vat lab, would be capable of inquiring about the brain’s nature, because the scientist has had a real impression of the brain in the vat.

A Solution to the Problem of Mental and Physical?

At this time in the argument, Hume proposes his ‘solution’ to the representation problem.  He eloquently states that a question of the external world is one which we lack the capacity to raise, just as the brain in the vat lacks the capacity to inquire about its own true nature.  Under this view, the representation problem can never be solved, so there is no reason to worry about it.  Up to this point, solutions to the problem of representation have basically been circular arguments of what Hume calls Pyrohonian Skepticism.  In this type of skepticism everything is doubted in order to come up with an indisputable argument.  Descartes perfected this process when he used methodical doubt to discover the cogito.  Hume uses what he calls Mitigated Skepticism in his inquiries.  The word mitigated literally means ‘less severe,’ and this essentially is what Hume’s turns out to be.  He believes that our inquiries should be kept within the bounds of what it is possible to know, and that way philosophers can be free of unsolvable problems.

Of the many possible solutions posed to the representation problem, Hume’s is the most mature and reasonable.  Hume calls it like he sees it; he is a fair umpire in the problem of perception and true reality.  Human beings, in the state which they presently exist, lack the ability to step outside of their own experience.  Reduction of the mental to the physical, or the physical to the mental, or any of the other solutions, do not have enough grounding to make for a plausible personal belief.  Excessive skepticism seems to lead only to more questions.  After coming to understand Hume’s solution, one can sigh in relief from a circle of questions.  Only a being which exists outside the human physical and mental worlds could have a point of view sufficient enough to look in on this experience and explain it with ample certainty.  Why try to play God and pretend to be capable of knowing the unknowable?  Hume knew the futility in this, and by staying within his means he was able to eliminate the problem of representation.

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