Friday, August 10, 2012

Much Undead Ado About Nothing

As mentioned in an earlier post, the debate about what it means to be human has taken an interesting direction following the recent fixation with zombies. The Walking Dead and Philosophy opened with two essays arguing that the consideration of philosophical zombies (P-Zombies) - theoretical beings identical to human beings but lacking consciousness, qualia, or sentience -  mitigates against a purely materialistic view of the world.  

There is a clear difference between P-Zombies (who are biologically identical to humans) and actual humans.  Something besides biology seems to be necessary to explain consciousness, mind, thoughts, ideas, and emotions.  

I find the intellectual speculation to be both insightful and entertaining.  The zombie analogy provides a way to decipher the nature of humanity, at least at a theoretical level.
 Robert Delfino and Kyle Taylor (“Walking Contradictions”)  take the discussion in The Walking Dead and Philosophy a step further. Is the idea of real zombies even coherent, or are we just making a lot of undead ado about nothing? 

Their argument builds from two key laws in logic - the Law of Identity and the Law of Non-Contradiction -  to argue that a thing cannot exist in such a way that is incompatible with its nature. A thing with mutually exclusive properties cannot exist (like a square circle, or a sane University of Michigan fan). In the same way, a being with mutually exclusive properties cannot exist either. Since the Walkers try to hold two mutually exclusive properties in tension (both physically alive and physically dead), they would seem to be impossible.  
 But not so fast!  Some quasi-living beings (such as viruses and viroids) appear to do just that. One type of fungi can take over carpenter ants and make them act like, well, zombie ants.  And if you’ve seen Twilight, you know that zombie actors can even carry commercially successful films. 

As (kind of) cool as this sounds, we are comparing fungi apples with zombie oranges. Viruses cannot use dead cells as hosts, and the organs and senses will by no means continue to function. These viruses and their host will also need energy, which requires a working digestive system. This is clearly not the case with zombies (think of the Walkers in The Walking Dead who continue to exist and move even when missing their entire body below the chest).

If zombies actually existed, they would be creatures that burn energy without consuming energy; move because viruses that need live cells are using dead cells; and hear, see, and smell with non-functioning sense organs. Zombies would be physically alive and physically dead simultaneously. They would be incompatible with their own nature, and thus impossible beings. Therefore, they cannot actually exist.

The logic of this conclusion would seem to apply in a much broader fashion as well. If we can show that a philosophy of humanity creates an impossible scenario or an impossible being, we have good reason to reject the theory as well.

Daniel Dennett says that “...mechanistic theories of, in fact, explain everything about consciousness that needs explanation."   We may think we are conscious people with subjective experiences of rationality, self-awareness, thoughts, ideas, and emotions, but we aren't. If Dennett is correct, then at some level “machines,” “conscious beings," and "humans" must have at least compatible, if not interchangeable, natures.  But do we have compelling reason to believe that our subjective experiences can be reduced to emergent qualities of complex biological and chemical machinery?

After discussing two popular thought experiments about this subject (The Turing Test and John Searles' Chinese Room Argument), the Internet Encyclopedia of Philosophy concluded:
 ‘He [Searles] says that computers or robots are just not made of the right stuff with the right kind of “causal powers” to produce genuine thought or consciousness. After all, even a materialist does not have to allow that any kind of physical stuff can produce consciousness any more than any type of physical substance can, say, conduct electricity. Of course, this raises a whole host of other questions which go to the heart of the metaphysics of consciousness. To what extent must an organism or system be physiologically like us in order to be conscious? Why is having a certain biological or chemical make up necessary for consciousness? Why exactly couldn’t an appropriately built robot be capable of having conscious mental states? How could we even know either way? However one answers these questions, it seems that building a truly conscious Commander Data is, at best, still just science fiction.”
Apparently mechanistic theories of consciousness do not, in fact, explain everything about consciousness that needs explanation. There appears to be more to the human machine than just machinery.


  1. Hi Anthony,

    I don't understand how you've derived the following sentence from Dennett's remark: "We may think we are conscious people with subjective experiences of rationality, self-awareness, thoughts, ideas, and emotions, but we aren't." To me there doesn't seem to be any necessary connection - indeed, any connection at all - between an explanation that something works by a particular mechanism and an explanation that something does not exist.

    For example, people used to think that inherited traits were carried by the blood, or in the gemmules, or by something more mystical. In the last century we've discovered that inherited traits are carried by DNA, and are in some cases able to explain exactly how this works. Does this imply that we have shown that inherited traits do not exist? I don't think so. Inherited traits exist to exactly the same degree they did before, but we now have an explanation of a phenomenon for which we previously had only an observation.

    We currently have lots of observations about rationality, self-awareness, thoughts, ideas, and emotions. What we lack are explanations for these phenomena. But obtaining an explanation doesn't make the observations go away.

    Do you disagree?

    1. In general, I agree, but I would probably rephrase in this case. We don't actually observe rationality, etc. like we do DNA. We can't put self-awareness and emotions in a lab. Your example of DNA is a scientific claim of a different kind. Perhaps it's better to say we have a lot of experiential knowledge of the things I mentioned. We observe people doing rational things, or exhibiting emotion, or acting self-aware, but that does not strike me as the same thing as looking at DNA.
      I agree with you that explaining the cause by which an effect is brought about does not make the effect disappear. That's my frustration with Dennett. If I understand him correctly (and feel free to let me know if I am wrong), he does say a material causal explanation of consciousness means "consciousness" does not exist (I have heard the word "interiority" used here as well). He doesn't agree with the P-Zombie scenario because he thinks it mitigates against materialism; he disagrees because he thinks the scenario is unnecessary, because that's what we obviously are.
      Why? Because he believes the cause is entirely material, and material things do not give rise to immaterial ones. He says we are to adopt an intentional stance toward other people (attributing things metaphorically) whereby we grant them attributes they do not have - and that includes actually being conscious. He does not give an account for why or how or what conscious experiences are; he claims they don't exist in the first place.
      Dennett offers a "zimbo" to take the place of the philosophical zombie. It's just a zombie that has a "sophisticated internal mechanism" which leads it to believe it has internality. He says we humans are zimbos, "the 'victim' of the benign user illusion of its own virtual machine!."
      For Dennett, obtaining an explanation (even if it is purely theoretical) does make that which we thought we observed go away.
      Your main argument may be with Dennett, not me :)

  2. In the analogy of consciousness to inheritance, rationality is analogous to an inherited trait, while the underlying neurology is analogous to DNA. We observe people doing rational things, or exhibiting emotion, or acting self-aware, and I think that is similar to observing that children resemble parents. Of course, inheritance of traits is probably more susceptible to quantitative analysis than rationality and the like, but to a lay person it's just something that we observe in the world in an informal way, just like rationality and emotion.

    On Dennett: on page 406 of Consciousness Explained:

    Are zombies possible? They're not just possible, they're actual. We're all zombies*. Nobody is conscious - not in the systematically mysterious way that supports such doctrines as epiphenomenalism.
    *It would be an act of desperate intellectual dishonesty to quote this assertion out of context!

    That's one of my favorite footnotes of all time, BTW.

    The upshot is that while Dennett does deny the existence of a certain kind of consciousness - the mystical or metaphysical kind - he doesn't deny the existence of the phenomena which inspire us to ask questions about consciousness. He just thinks that those phenomena can - and should - be explained in terms of things which are less mysterious rather than more mysterious. (Mysterious here meaning "incomprehensible" not "currently unknown".) He says, "We're all zombies," because he thinks we are already in a state where we possess no mystical consciousness-stuff, just like a p-zombie, so it makes no sense to hypothesize about p-zombies who are different from us only in their lack of consciousness.

    Sorry, I'm a bit rushed. Does that make sense?