A philosophical zombie or p-zombie is a hypothetical entity that looks and behaves exactly like a human (often stipulated to be atom-by-atom identical to a human) but is not actually conscious: they are often said to lack phenomenal consciousness.
A p-zombie is as likely as anyone else to ask, “When I see red, do I see the same color that you see when you see red?”, but they have no real experience of the color red; the zombie’s speech must be explained in some other terms which do not require them to have real experiences.
The zombie thought experiment is purported to show that consciousness cannot be reduced to merely physical things: our universe is purported to perhaps have special “bridging laws” which bring a mind into existence when there are atoms in a suitably brain-like configuration.
Physicalists typically deny the possibility of zombies: if a p-zombie is atom-by-atom identical to a human being in our universe, then our speech can be explained by the same mechanisms as the zombie’s — and yet it would seem awfully peculiar that our words and actions would have an entirely materialistic explanation, but also, furthermore, our universe happens to contain exactly the right bridging law such that our utterances about consciousness are true and our consciousness syncs up with what our merely physical bodies do. It’s too much of a stretch: Occam’s razor dictates that we favor a monistic universe with one uniform set of laws.
Other physicalists accept the possibility of p-zombies, but insist that we are p-zombies and consciousness is an illusion.
Non-physicalists use the apparent conceivability of p-zombies to argue that it is impossible to explain how phenomenal consciousness arises using physical facts alone. P-zombies are presumably not possible in our universe, but they are conceivable (on this view) because a physically identical universe with different psychophysical bridging laws or different quiddities could indeed harbor p-zombies.
External links
Zombies, Stanford Encyclopedia of Philosophy
See also
Tags: Consciousness
Sequences: Physicalism 201
Wiki pages: How an algorithm feels, Making beliefs pay rent
Merge these posts into the ‘Consciousness’ tag (no need for a separate ‘zombie’ tag). Can leave this up as a pure wiki/glossary page if wanted.
I have converted it to wiki-only now.
It seems like a separate ‘zombie’ tag might be useful if people are specifically looking to read people’s thoughts on p-zombies, as opposed to just reading about consciousness in general. (There’s probably some inferential step I’m not catching on to, though).
The set of posts that are about ‘p-zombies’, ‘the hard problem of consciousness’, ‘phenomenal consciousness’, ‘Mary’s room thought experiments’, ‘the mysterious redness of red’, ‘the explanatory gap for qualia’, ‘arguments for and against epiphenomenalism’, etc. are more or less talking about the same topic. I think it’s more useful to lump those together than split them apart, since those aren’t the kinds of conversations we want to fragment off from each other; someone who follows the latest debate about zombies should also be paying attention to the latest debates about Mary’s room, and vice versa.
I’m less confident about whether that hub page should be the ‘consciousness’ tag. Another option would be to make ‘consciousness’ a disambiguation page, and have a clearer name for the ‘hard problem of consciousness’ discussion. But this is a pretty disputed topic, so giving it a clearer name might be seen as biasing the conversation. (E.g., some people might object that the ‘hard problem’ isn’t hard, or isn’t a real problem.)
I guess I also have a bit of a minimalist philosophy about tags, which I might be talked out of if I hear others’ perspectives. Tags create more work by forcing future users to remember ‘oh yeah, there’s a tag for [X]‘, and by forcing users to upkeep the tag indefinitely (lest it get confusing which posts are where). If a tag is only mildly useful, I’d usually prefer replacing it with a static list of ‘here are some useful places to start if you want to read about zombies on LessWrong’. The page could even remind people that ‘zombies’ is very text-search-friendly on LW.
Thanks for responding so quickly!
I agree with you now (and I’m going to agree with your minimalist policy for now too, just since I think you’re better-informed than me).
Minor clarification that you might have already been aware of: I was thinking that posts tagged ‘zombie’ should also be tagged ‘consciousness’, if they didn’t merge. Now I’m fairly sure they should be merged.