Dennett's "Consciousness Explained": Chpt 2

post by PhilGoetz · 2010-01-10T23:38:55.449Z · LW · GW · Legacy · 25 comments

Contents

  Chapter 2: Explaining Consciousness
    1. Should consciousness be demystified?
    2. The mystery of consciousness
    3. The attractions of mind stuff
    4. Why dualism is forlorn
    5. The challenge
    Summary
None
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Chapter 2: Explaining Consciousness

This chapter is all about dualism and why it's bad.  I find this chapter incoherent, because Dennett never defines dualism carefully, and confuses it with the theistic views historically associated with dualism.

[Long stretches of my own ideas will be in brackets, like this.]

1. Should consciousness be demystified?

D begins with a defense against those who don't want an explanation of consciousness.  I'm not even going to read this section.

2. The mystery of consciousness

"What could be more obvious or certain to each of us than that he or she is a conscious subject of experience, an enjoyer of perceptions and sensations, a sufferer of pain, an entertainer of ideas, and a conscious deliberator? ... How can living physical bodies in the physical world produce such phenomena?"

3. The attractions of mind stuff

D says Searle describes functionalism by saying that if a computer program reproduced the entire functional structure of a human wine taster's cognitive system, functionalism says that it would reproduce all the mental properties, including enjoyment.  This is followed by a [long, pointless, popular] discussion of whether volcanos, hurricanes, etc., have souls.

The "mind stuff" position D sets up in order to knock down is not John Searle's "mind stuff" position, nor Roger Penrose's, but something spiritual and non-physical.  He says that the mind-stuff view is that "the conscious mind... cannot just be the brain... because nothing in the brain could appreciate wine."  [D should pursue this further, because the summary given of the "mind stuff" view is too incoherent to attack.]

4. Why dualism is forlorn

D says that the "mind stuff" view is that the brain is "composed not of ordinary matter", and is dualism.  Materialists, OTOH, say we can account for all mental phenomena using the same principles that explain other things.  Dualism is bad; materialism is good.

D says that if dualism were true, then the mind would need to act on our body, so we could move our arms.  But to move, a physical thing needs energy; and how can non-matter produce energy?  Dualism is thus dead, QED.

[IMHO this muddies the waters terribly, in a way I've seen them muddied many times before.  The dichotomy between dualism and materialism is a false dichotomy.  There are no "materialists" who believe only in a kinematic world.  (Ironically, Descartes, the classic dualist, was just such a materialist when it came to the physical world; he refused to believe in gravity for that reason.)  The physics that we believe in is full of other forces such as gravity, electricity, and magnetism.  Energy can exist in all these forms, as well as in matter.  D is one of the many who reject "dualism", yet accept the everyday mysterious forces; and presumably approve of people who accepted them long before there was any material explanation of them.

If we want to be able to dismiss people for positing new "stuff", the way we currently do by calling them dualists, then we need a way to distinguish an acceptable new fundamental force or type of being, such as gravity, from an unacceptable one.  Obeying the law of conservation of energy is one such rule; if Descartes wants to have a non-material soul, it must exchange energy with ordinary matter in predictable ways.  To put it another way, rejecting "dualism" can make sense if we define dualism as the belief in things that don't obey conservation laws.

Once we've done that, though, we find that all the old enemies we hoped to dismiss as dualists can sneak back in by claiming to observe the conservation laws.  Even magic systems in fantasy worlds often obey energy conservation laws.

Even this conservative position is problematic.  EY believes in many worlds.  Many worlds seems, at least to many people like me who consider it a respectable position without understanding it, to require a stupendous, continual violation of conservation laws.  But we don't usually therefore call EY a "bad dualist" and dismiss many-worlds.

My intuition is that we are willing to consider even very crazy-sounding new proposed extensions to physics, if we believe they are made with a sincere desire to understand the universe.  Historically, a "dualist" is usually someone, such as Descartes, who is trying to come up with an excuse for not trying to understand the universe.  The term "dualist" is an accusation against a person's intent masquerading as an objection to their physics.]

D also refutes dualism by saying that mind stuff can't both elude physical measurement, and control the body; as anything that escapes our instruments of detection can't possibly interact with the body to control it.  [The problem with this argument is that, 200 years ago, if someone had told you that the brain used electrical impulses, you could have used the exact same argument to "prove" that that was impossible.]

D considers this angle on the next page, without realizing that it devastates his last several pages of argument:  "Perhaps some basic enlargement of the ontology of the physical sciences is called for in order to account for the phenomena of consciousness."

He also gives us what I take to be the defining characteristic of "bad" dualism: "The few dualists to avow their views openly have all candidly and comfortably announced that they have no theory whatever of how the mind works -- something, they insist, that is quite beyond human ken."  [This shows us that what D dismisses as "dualism" has nothing to do with making a dualistic distinction between matter and non-matter; and everything to do with the intentions of the theorist.  What D objects to as "dualism" is actually the God argument that has been historically associated with dualism:  Stopping further inquiry by positing the existence of something that a) explains, and b) cannot be explained.]

5. The challenge

D lays down rules for himself to follow: To explain consciousness, with only existing science, while acknowledging his own conscious experience.

Summary

[This chapter will confuse more than inform.  Its only purpose is to refute dualism; but D hasn't taken a close look at what he means when he uses that word, so he mingles together its meaning and its associations and historical contingiencies indiscriminately.]

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