Sunday, March 1, 2009

Dennett on Zombies

The Zombic Hunch:
Must we talk about zombies? Apparently we must. There is a powerful and ubiquitous intuition that computational, mechanistic models of consciousness, of the sort we naturalists favor, must leave something out–something important. Just what must they leave out? The critics have found that it’s hard to say, exactly: qualia, feelings, emotions, the what-it’s-likeness (Nagel)[13] or the ontological subjectivity (Searle)[14] of consciousness. Each of these attempts to characterize the phantom residue has met with serious objections and been abandoned by many who nevertheless want to cling to the intuition, so there has been a gradual process of distillation, leaving just about all the reactionaries, for all their disagreements among themselves, united in the conviction that there is a real difference between a conscious person and a perfect zombie–let’s call that intuition the Zombic Hunch–leading them to the thesis of Zombism: that the fundamental flaw in any mechanistic theory of consciousness is that it cannot account for this important difference.[15] A hundred years from now, I expect this claim will be scarcely credible, but let the record show that in 1999, John Searle, David Chalmers, Colin McGinn, Joseph Levine and many other philosophers of mind don’t just feel the tug of the Zombic Hunch (I can feel the tug as well as anybody), they credit it. They are, however reluctantly, Zombists, who maintain that the zombie challenge is a serious criticism. It is not that they don’t recognize the awkwardness of their position. The threadbare stereotype of philosophers passionately arguing about how many angels can dance on the head of a pin is not much improved when the topic is updated to whether zombies–admitted by all to be imaginary beings–are (1) metaphysically impossible, (2) logically impossible, (3) physically impossible, or just (4) extremely unlikely to exist. The reactionaries have acknowledged that many who take zombies seriously have simply failed to imagine the prospect correctly. For instance, if you were surprised by my claim that the Steinberg cartoon would be an equally apt metaphorical depiction of the goings on in a zombie’s head, you had not heretofore understood what a zombie is (and isn’t). More pointedly, if you still think that Chalmers and I are just wrong about this, you are simply operating with a mistaken concept of zombies, one that is irrelevant to the philosophical discussion. (I mention this because I have found that many onlookers, scientists in particular, have a hard time believing that philosophers can be taking such a preposterous idea as zombies seriously, so they generously replace it with some idea that one can take seriously–but one that does not do the requisite philosophical work. Just remember, by definition, a zombie behaves indistinguishably from a conscious being–in all possible tests, including not only answers to questions [as in the Turing test] but psychophysical tests, neurophysiological tests–all tests that any “third-person” science can devise.)

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