Chapter 15
The Philosophical Zombie Meets The Ixperiencitness Zombie
The philosophical zombie (or "p-zombie") is one of the most famous thought experiments in the philosophy of mind. It imagines a being that is physically identical to you in every way (same atoms, same structure, same functioning) but that has no conscious experience at all. It behaves exactly like you, responds to stimuli exactly like you, but there is "nobody home." The lights are on, but nobody is in.
Philosophers use the p-zombie to argue about the nature of consciousness. Can we conceive of a p-zombie? If so, does that prove that consciousness is something over and above the physical pattern?
Ixperiencit Theory has a clear answer to this question, and it also introduces a new and more interesting variant: the ixperiencitness zombie.
The Standard Zombie
Can a body with identical structure and functioning to yours be completely unconscious? Ixperiencit Theory says no. If our premises are correct (if structure and functioning produce consciousness) then identical physical organization must produce identical consciousness. A p-zombie is logically impossible given our premises, not a matter of practical difficulty but of logical contradiction.
Chalmers disagrees, and his argument deserves respect. His position is that we can coherently conceive of a p-zombie, that there is no logical contradiction in imagining a physically identical being that lacks experience. If this conceivability is genuine (and not just a failure of imagination), then it follows that consciousness is not logically necessitated by physical structure. There must be something more, some psychophysical law or fundamental property, that links the physical to the experiential.
Here is where Ixperiencit Theory parts company with Chalmers, but perhaps less dramatically than you might expect.
More importantly for our purposes: even if Chalmers is right that consciousness involves something beyond physical structure, his own view (property dualism) holds that consciousness lawfully accompanies physical structure. Identical structure, identical consciousness, not because consciousness reduces to structure, but because the psychophysical laws are consistent. If so, all three premises of Ixperiencit Theory survive, and the argument for superimmortality goes through.
The p-zombie debate is a deep one, and I do not claim to have settled it here. (We engage with Chalmers's full position more carefully in Part Four, where we steelman the strongest objections to the theory.) What matters for our purposes is this: whether consciousness reduces to structure and functioning (physicalism) or accompanies structure and functioning (Chalmers's property dualism), identical structure and functioning produces identical consciousness. And that is all the argument requires.
The Ixperiencitness Zombie
But Ixperiencit Theory introduces a more subtle and more interesting concept: the ixperiencitness zombie.
An ixperiencitness zombie is a being that is conscious — it has subjective experience — but that does not have your ixperiencitness. It experiences being conscious, but it does not experience being you. It has somebody home, but that somebody is not you.
Consider a body with physical organization similar to yours but not identical. It might be a brain with slightly different neural wiring, or different neurotransmitter levels, or a different pattern of synaptic strengths. This brain produces consciousness — but it produces a consciousness with a different ixperiencitness than yours.
This has important implications for the science of superimmortality. It means that accurately reproducing your ixperiencitness requires more than just reproducing your behavior. It requires reproducing the brain's underlying architecture with sufficient fidelity that the same ixperiencitness is produced. How much fidelity is "sufficient" is a scientific question that we do not yet have the tools to answer. But the principle is clear.
Key Terms in This Chapter
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The remaining text (examples, counter-arguments, and longer connective passages) is in the book.