Friday, August 12, 2005

Zombie Philosophers

It's really amusing to consider the philosophical debates that occur in the zombie world. Remember that it's physically indistinguishable from our own world. So there's this thriving discipline called "philosophy of mind", where all the zombies sit around discussing the mystery of consciousness, and disputing the far-fetched possibility that maybe there's some distant possible world that's just like their world "except full of zombies!" ("Impossible!" another zombie replies.) Oh dear. What if that's us?

[Update: But see section 4.3 of Chalmers' article here.]


  1. Why not? Epiphenomenalism merely requires that consciousness has no causal impact. But belief content may be partly dependent upon non-causal properties (particularly, phenomenal properties). In which case, different beliefs would be entirely consistent with epiphenomenalism.

    (I find it pretty intuitive myself, that phenomenology is partly constitutive of belief. Sure, we can ascribe a kind of belief-like state to zombies, so long as we take care to recall that all we mean by this is a complex dispositional behavioural state. We can ascribe similar kinds of states to insects. That's something very different from the thoroughly mental (and partly phenomenal) state more commonly associated with the term 'belief', and restricted to fully sentient beings like ourselves. So really, I don't think zombies can be properly said to have beliefs at all.)

  2. Something strange just occurred to me about zombie world, and I'm sure I'm not the first to think about this, but I'll throw it out there regardless:

    I believe that I am conscious, my zombie doppelganger believes himself to be conscious, and yet (we should hope) my belief is true and his belief is false. We might conclude that I have knowledge of my own consciousness, and that my twin does not.

    But here's something strange...since our brains are ex hypothesi exact duplicates, we both arrived at our beliefs via the same process. How could my belief that I am conscious be justified if my zombie twin's belief is unjustified?

    We might think that his belief is also justified, but just not true, and so it doesn't count as knowledge. Isn't it counter-intuitive though that a zombie could have a justified belief in his own consciousness?

    What do you guys think?

  3. One way to get around this is suggested in my above comment: deny that zombies really have full-blown beliefs at all. They have certain behaviour dispositions, that's all.

    Alternatively, we can hold that justification does not supervene on causal processes. Even if my zombie and I have the same belief-like brain states, with identical physical/causal origins, still my state alone might be justified because I alone have had the conscious experiences which justify the belief.

  4. My brain and my zombie doppelganger's brain are exact duplicates. So if he lacks a belief that I have, then belief cannot be just in the head. You've got to be some kind of externalist about belief in order to support this option. This is weird. And not weird like Jeff Goldblum; weird like Michael Jackson.

    The second notion is equally strange to me, because it makes justification intangible and epistemically-inaccessible. It substitutes an acausal state for a causal process, viz. the state of being--in a way, magically--justified, for the process of justification.

    Of the many many concerns that I would have with such a theory is that it simply delays (and does not avoid) reference to causation. How is it that a believer comes to be in the justified state? Any causes of my states will also be causes of zombie states. The problem comes back from the grave, as it were.

  5. But our conscious experiences are not "epistemically inaccessible". Just the opposite: we seem to have direct access to them, unlike our causally mediated access to the external world.

    As for externalism: (1) I thought that was pretty widely accepted after Putnam's Twin Earth case? You know, Oscar and Toscar with the same brains but different beliefs about what nearby liquid (water or twater) is wet. (2) Regardless, I don't think the property dualist is committed to any such thing. Belief-facts aren't settled by brain-facts alone, simply because brain-facts alone do not settle the consciousness-facts (as the zombie world teaches us). Does that mean consciousness is somehow not "in the head"? More plausibly, it merely shows that a necessary precondition for consciousness, viz. the appropriate psychophysical natural laws, are not in the head. The brain facts may be nomologically sufficient to settle all this other stuff (consciousness, beliefs), so that doesn't sound so "externalist" to me.

  6. [Testing the new and improved 'recent comments' feature...]


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