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7 Materialism: The Brain As Computer
is the same—but they are not conscious. We even allow them to have beliefs,
thoughts and decision-making processes such as ours, but in Zombies these
processes are directly connected to behavior and don’t lead to awareness. For
example, when Normal Jack and Zombie Zack each take a bite of chocolate
cake, they both have the same reaction: They both comment on how delicious
it is and ask for a second helping. But only Jack has the sensation of its taste
and is aware of the pleasure.
The upshot of this story is that Jack’s awareness—his feelings and sensations—
are something over and above the physical facts. From this, one is expected to
conclude that consciousness must be nonphysical. Although this story argues
against physicalism, it has the unfortunate consequence of suggesting that sentient awareness serves no purpose and that people and animals could very well
get along without it. This viewpoint is called eliminativism, and is staunchly
defended by many neuroscientists. You might say that it is an extreme form of
physicalism.
... But not the most extreme: A number of very clever people would like to
convince us that subjective feels don’t exist at all. Daniel Dennett, for example, would like to reverse our ‘mistaken’ intuitions about consciousness and
prove that the special qualities we seem to experience when we taste sweet
or see the color red are not real, and their existence cannot be defended
except by appealing to something mysterious outside the bounds of nature. To
illustrate his viewpoint, he too proposes a modern myth, or as he calls it, an
“intuition-pump”.
Mr. Chase and Mr. Sanborn are coffee tasters. One day Chase says, “You
know, today the coffee isn’t the same to me—the taste has changed.” Sanborn
replies that he too notices a difference, but the difference is in his taste buds, and
the coffee’s taste is exactly as before. Who’s right—Chase or Sanborn? Chemical
analysis would be able to detect any possible change in the chemistry of the
coffee, but would not reveal a change in its taste. Since taste is what this is
about, there is no fact of the matter of who’s right. 4
Dennett takes this as a typical illustration of the fact that subjective qualities
such as taste have no relevance to the real world. They may be very real in the
mind, but they have no objective validity. In particular, they lack any power
whatever to affect things in external reality.
The reluctance to accept the existence of anything non-physical is not
entirely new in science. In the Seventeenth Century, the idea of electromagnetic waves traveling through space, in the absence of material support, was
considered implausible. Electromagnetism and gravitation do not conform
to the laws of classical physics in which force is relayed by physical contact.
Instead, they appear to be some kind of spooky action at a distance. Magnetism
7 Materialism: The Brain As Computer
is the same—but they are not conscious. We even allow them to have beliefs,
thoughts and decision-making processes such as ours, but in Zombies these
processes are directly connected to behavior and don’t lead to awareness. For
example, when Normal Jack and Zombie Zack each take a bite of chocolate
cake, they both have the same reaction: They both comment on how delicious
it is and ask for a second helping. But only Jack has the sensation of its taste
and is aware of the pleasure.
The upshot of this story is that Jack’s awareness—his feelings and sensations—
are something over and above the physical facts. From this, one is expected to
conclude that consciousness must be nonphysical. Although this story argues
against physicalism, it has the unfortunate consequence of suggesting that sentient awareness serves no purpose and that people and animals could very well
get along without it. This viewpoint is called eliminativism, and is staunchly
defended by many neuroscientists. You might say that it is an extreme form of
physicalism.
... But not the most extreme: A number of very clever people would like to
convince us that subjective feels don’t exist at all. Daniel Dennett, for example, would like to reverse our ‘mistaken’ intuitions about consciousness and
prove that the special qualities we seem to experience when we taste sweet
or see the color red are not real, and their existence cannot be defended
except by appealing to something mysterious outside the bounds of nature. To
illustrate his viewpoint, he too proposes a modern myth, or as he calls it, an
“intuition-pump”.
Mr. Chase and Mr. Sanborn are coffee tasters. One day Chase says, “You
know, today the coffee isn’t the same to me—the taste has changed.” Sanborn
replies that he too notices a difference, but the difference is in his taste buds, and
the coffee’s taste is exactly as before. Who’s right—Chase or Sanborn? Chemical
analysis would be able to detect any possible change in the chemistry of the
coffee, but would not reveal a change in its taste. Since taste is what this is
about, there is no fact of the matter of who’s right. 4
Dennett takes this as a typical illustration of the fact that subjective qualities
such as taste have no relevance to the real world. They may be very real in the
mind, but they have no objective validity. In particular, they lack any power
whatever to affect things in external reality.
The reluctance to accept the existence of anything non-physical is not
entirely new in science. In the Seventeenth Century, the idea of electromagnetic waves traveling through space, in the absence of material support, was
considered implausible. Electromagnetism and gravitation do not conform
to the laws of classical physics in which force is relayed by physical contact.
Instead, they appear to be some kind of spooky action at a distance. Magnetism