I am pretty sure that a philosophers’ zombie is conceptually incoherent, impossible, a bankrupt idea. But don’t take my word for it. What could you do to convince yourself that you can conceive of a philosophers’ zombie? Suppose you try to imagine that your friend Zeke “turns out to be” a zombie. What would convince you or even tempt you to conclude that this is so? What difference would make all the difference? Remember, nothing Zeke could do should convince you that Zeke is, or isn’t, a zombie. I find that many people don’t do this exercise correctly; that is, they inconveniently forget or set aside part of the definition of a philosophers’ zombie when they attempt their feat of conception.
It may help you see if you are making this mistake if we distinguish a special subspecies of zombies that I call zimboes (Dennett, 1991a). All zombies have nonconscious (of course) control systems that extract information from the world (via their zombie eyeballs and ears) and exploit that information to avoid walking into walls and to turn when you call, and so on. They are all intentional systems, in other words. But a zimbo is special, a zombie that is also blessed with equipment that permits it to monitor its own activities, both internal and external, so it has internal (nonconscious) higher-order informational states that are about its other internal states. Further self-monitoring allows a zimbo to have and use information about those very self-monitoring states, and so on, indefinitely. A zimbo, in other words, is equipped with recursive self-representation—unconscious recursive selfrepresentation, if that makes any sense.
I can imagine that there might be two (or seven, or ninety-nine) different sorts of so-called consciousness, and lefties have one, and righties have another, and lobsters have yet another. But the only way I can imagine this (so far) is by imagining that they are distinguishable by the following functional differences: lefties can’t do X, and righties can’t do Y, and so on. But those distinguishable differences just go to show that we’re not talking about philosophical zombies after all, for (by definition) there are no distinguishable-from-the-outside differences between philosophical zombies and “genuinely conscious” people. The whole idea of a philosophical zombie is a sort of intellectual hallucination, an affliction one can outgrow.
Source:
Philosopher Daniel Dennett’s Book Intuition Pumps
