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I've never understood why Chalmer's reasoning is so captivating to people. The whole idea of p-zombies seems absurd on its face. Quoting the article: (quote)

I've never understood why Chalmer's reasoning is so captivating to people. The whole idea of p-zombies seems absurd on its face. Quoting the article: (quote) His core argument against materialism, in its original form, is deceptively (and delightfully) simple: 1. In our world, there are conscious experiences. 2. There is a logically possible world physically identical to ours, in which the positive facts about consciousness in our world do not hold. 3. Therefore, facts about consciousness are further facts about our world, over and above the physical facts. 4. So, materialism is false. (endquote) Point 2 is textbook begging the question: it imagines a world which is physically identical to ours but consciousness is different there. That is baking in the presupposition that consciousness is not a physical process. Points 3 and 4 then "cleverly" detect the very contradiction he has planted and claims victory.

codeflo 2y ago
If you believe that what we describe as "consciousness" is emergent from the ideas a material brain develops about itself, then it's in fact not logically possible to have a world that is physically identical to ours yet does not contain consciousness. So indeed, premise 2. sneaks in the conclusion. To illustrate this point, here's an argument with the same structure that would similarly "prove" that gravity doesn't cause things to fall down: 1. In our world, there is gravity and things fall down. 2. There is a logically possible world where there is gravity yet things do not fall down. 3. Therefore, things falling down is a further fact about our world, over and above gravity. 4. So, gravity causing things to fall down is false.
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- goatlover 2y ago
  But Chalmers doesn't think that approach works, nor any other physicalist attempt to explain consciousness. The problem with what you stated is that you're substituting ideas about consciousness for sensations. And those aren't the same thing. We experience sensations as part of being embodied organisms, and then we think about those sensations.
  - codeflo 2y ago
    I’m making an argument about the validity of an argument. A rebuttal to that can never be “but the conclusion is true”.
  - tsimionescu 2y ago
    It's quite clear if you approach these things logically that Chalmers doesn't do a lot of thinking before coming up with these arguments. All of his arguments boil down to "if we assume that consciousness is different from everything else, then it's different from everything else". He gets way, way too much attention for someone who is sub mediocre in his reasoning. He also doesn't understand what computation is, even though he often makes confident statements about it. He thinks computation is a subjective process, that something only counts as a computation if someone interprets it as such, which is simply wrong, not a debatable topic. And this is the core of one of his other arguments about why consciousness can't be a computational process.
    - mensetmanusman 2y ago
      There are a number of ways to determine that consciousness is not a computational process. Roger Penrose is a good source on this.
      - tsimionescu 2y ago
        There is not. It's by the far the most likely explanation, and even if you don't agree with that, it is at least completely consistent with everything we know about computation.
        mensetmanusman 2y ago
        For one, you would have to determine whether physical laws are computational processes. Stephen Wolfram is trying this, but it requires some incredible assumptions.
        2y ago
- mistermann 2y ago
  > If you believe that what we describe as "consciousness" is emergent from the ideas a material brain develops about itself, then it's in fact not logically possible to have a world that is physically identical to ours yet does not contain consciousness. This sneaks in an implicit axiom: that the brain is not only necessary, but is also sufficient, necessarily, for consciousness (implicitly ruling out some unknown outside, non-materialistic force(s)).
- empath75 2y ago
  I don't think your point 2 is directly analogous to his point 2. Because a world where things do not fall down is not physically identical to a world in which they don't. I think the point of arguing about p-zombies is this. Do you believe it's possible for a human being to exhibit all the external characteristics of consciousness without an internal conscious experience? And if you believe that's true, then you can posit a world which is physically indistinguishable from our world through any experiment in which consciousness simply does not exist, because, as far as I know, there is no test that can prove that an individual does have an internal consciousness, and isn't merely mimicking it. Most arguments that p-zombies don't exist sort of rely on the internal conscious experience of the person making it, which no one else has access to -- "I have an internal conscious experience of the world, other people are similar to me and so they must also have those experiences." That is _not_ true about a world in which gravity does not exist for obvious reasons. That universe would be very different from ours and easily distinguishible through experiment. I think his point does hinge on whether it's possible for p-zombies to exist, but it's not as silly as you all are making it out to be, and it is not begging the question. I actually think his weakest point is part 3 and 4, because I think mostly the problem is that we don't really have good definitions of consciousness and related concepts let alone a complete physical explanation of their origins, and his whole argument hinges on the fact that we currently don't have a way to test for internal conscious experience, but I think that might not always be true.
  - observationist 2y ago
    You experience your own consciousness - your own model of your self, time, and the world as perceived through your physical sensory apparatus. This could give you a probability of 100% certainty of your own consciousness. You're a good skeptic, though, and after much consideration, you decide that, despite absence of evidence to the contrary, you'll allow for 2% uncertainty, since you might be a simulation specifically designed to "feel" conscious, or some other bizarre circumstance. Knowing this, you compare your own experience with reports by others, and find that, despite some startling variety in social and cultural practice, humans all more or less go through life experiencing the world in a way that more or less maps to your own experiences. You find that even Helen Keller, despite her tragic disability, wrote about experiences which you can simulate for yourself. You conclude that if you somehow swapped places with her, she would be able to map the sensory input of your physical sensors to her own experience of the world, and vice versa. This leads you to think that our physical brains are performing a process that models the world, and it does so consistently. After reading up on people's experiences, you also learn that our subjective experiences are constructed, moment by moment, by a combination of these world models, real-time stimulation, abstract feedback loops of conscious and unconscious thinking. The more you read, the more evidence you have of this strange loop being the default case for every instance of a human having a brain and being alive. The Bayesian probability that you are conscious, because of your brain, given all available evidence, approaches 100% certainty. You conclude your brain is more or less the same as anyone else's brain, broadly speaking, and this is supported by the evidence provided by a vast majority of accounts from other similarly brained individuals through all of human history. Since your brain doesn't have a particular difference upon which to pin your experience of consciousness, and the evidence doesn't speak to any need for explanation, Occam's razor leads you to the conclusion that the simplest explanation is also the best. The living human brain is necessary and sufficient for consciousness, and consciousness is the default case for any living human brain. The posterior probability that any given human (with a "normal" living brain) is conscious approaches 100% certainty, unless you can specifically provide evidence to the contrary. Saying "but what if p-zombies exist" makes for a diverting thought experiment, but it's rationally equivalent to saying "but what if little invisible unicorns are the ones actually experiencing things" or "what if we're all in the Matrix and it's a simulation" or "what if we're just an oddly persistent Boltzmann brain in an energetic nebula somewhere in the universe." Without evidence, p-zombies are a plot device, not a legitimate rational launching off point for theorizing about anything serious. Humans are conscious. We have neural correlates, endless recorded evidence, all sorts of second hand reporting which can compare and contrast our own first hand experiences and arrive at rational conclusions. Insisting on some arbitrary threshold of double blind, first hand, objective replicable evidence is not necessary, and even a bit shortsighted and silly, since the thing we are talking about cannot be directly shared or communicated. At some point, we'll be able to map engrams and share conscious experience directly between brains using BCI, and the translation layer between individuals will be studied, and we'll have chains of double blinded, replicable experiments that give us visibility into the algorithms of conscious experience. Without direct interfaces to the brain and a robust knowledge of neural operation, we're left with tools of abstract reasoning. There's no good reason for p-zombies - they cannot exist, given the evidence, so we'd be better served by thinking about things that are real.
- mensetmanusman 2y ago
  Your Step 2 is so off as an analogy, it’s possible you don’t understand Chalmer’s point.
  - chr1 2y ago
    What is Chalmers saying then? As i understand he is saying that there can be a world where conciousness does not exist, but all the possible physical experiments cannot distinguish between that world and our world. But that simply means the conciousness he is looking for has absolutely no consequence, and therefore his point has no value...
    - mensetmanusman 2y ago
      He is saying that the person in the Chinese room doesn’t understand Chinese.
      - chr1 2y ago
        How is this related to the 2nd point in OP's comment? The whole Chinese room argument is based merely on a misinterpretation of computentionalist/physicalist argument. Of course the computer or person who executes the program does not understand Chinese, they are just performing arithmetic operations, the entity understanding Chinese is the program itself, not the medium on which the program runs.
patrickmay 2y ago
Well and succinctly put. One would have to be a philosopher to be willing to consider p-zombies further.
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- RaftPeople 2y ago
  Some of the arguments I've read by philosophers seem like they are focusing on pure logic to prove a point or find weakness in another, but the linkage between those logic stmts and reality don't always seem to be considered. It's almost like they are purely focused on symbolic logic, even if the stmts and symbols don't truly map to reality unambiguously, or without contradictions.
- empath75 2y ago
  I actually think it's worth asking the question if these advanced AIs are a kind of p-zombie.
  - Filligree 2y ago
    P-zombies are supposed to be physically identical to humans. They’re problematic because they lack consciousness, yet mysteriously talk about it anyway — among other reasons. Advanced AI is definitely not physically identical to humans, and there’s a well understood reason why they might talk about consciousness despite lacking it which doesn’t apply to p-zombies.
    - empath75 2y ago
      I'm not sure that being physically identical to humans is a necessary characteristic of a p-zombie for anything important. If you can produce an ai which _acts in every observable way as if it were conscious_ without any actual consciousness that would indicate that p-zombies are possible. The current generations of AI don't qualify, but I can see how to get there from here.
amelius 2y ago
> it imagines a world which is physically identical to ours but consciousness is different there So a world where people discuss consciousness but where it does not exist? That sounds very implausible.
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sornen 2y ago
Chalmers in point 2 is not saying to imagine such a world, but that such a world is logically possible. Chalmers gives as an example of a logical impossibility a male vixen since it is contradictory. He states "... a flying telephone is conceptually coherent, if a little out of the ordinary, so a flying telephone is logically possible. Nevertheless, that zombies are logically possible, may be begging the question, that consciousness is non physical.
- tasty_freeze 2y ago
  I'm still missing the point, I guess, as I don't think the question is logically possible. One might as well say: it is logically possible to have a universe where the physics are identical to our present world, except the core of the Sun is chocolate... therefore fusion can't be the explanation for why our Sun radiates so much energy. Getting back to the zombies, presuming there could be a zombie clone of me which is indistinguishable from the real me but it isn't conscious is one that needs far more support than just asserting it. I've heard people try to explain: well, imagine if a powerful computer was simulating you in every respect, that would be a p-zombie. But that is question begging, as it presumes that such a creature wouldn't be conscious. I feel the same way about Searle's Chinese Room -- the power of the argument is there only if you have already decided that consciousness is mystical.
- tsimionescu 2y ago
  But it's not logically possible if consciousness is a material process, a consequence of computation in the human brain (and potentially other places). So you can't prove that consciousness is not materialistic by assuming it's not materialistic.
- idiotsecant 2y ago
  I have known some pretty vixen-y males...
goatlover 2y ago
No, you have to take that argument in context of his other arguments against physical explanations for consciousness. What he's saying is that the physical facts do not adequately account for conscious experiences, which is why we can conceive of a universe physically identical lacking consciousness. Why he (and some other philosophers) think this is so is part of their larger arguments.
- Ukv 2y ago
  > which is why we can conceive of a universe physically identical lacking consciousness I can conceive of it about as well as I can conceive of an identical universe lacking the Internet. Both seem like fairly direct logical contradictions, slightly disguised by referring to concepts that we generally think about more abstractly rather than their physical composition.
- tsimionescu 2y ago
  If you examine all of his arguments, they all end up in the same place. He assumes that consciousness is not necessary for human-like or even animal-like intelligence, and he works from there back to the same conclusion.
hackinthebochs 2y ago
> Point 2 is textbook begging the question: it imagines a world which is physically identical to ours but consciousness is different there. It's not begging the question. He gives reasons for (2) that support the premise. That the premise essentially leads inexorably to (4) is a feature of the argument structure, not a bug. You have to engage with his reasons for (2) in determining whether or not the argument succeeds.
- tasty_freeze 2y ago
  Can you give an outline of some of that evidence? I haven't read source Chalmers, just other people's discussions of the topic (including the article that is the subject of this thread).
  - hackinthebochs 2y ago
    The argument is roughly that (1) we can conceive of the physical dynamics of this world occurring without any associated consciousness, (2) if something is conceivable then it is logically possible, (3) It is logically possible that the physical dynamics of this world occur without any associated consciousness. (1) is supported by noticing that all our explanations of physical dynamics appeals to other physical dynamics. We do not need to mention consciousness or qualitative anything to derive any of the physical dynamics we observe in this world. Thus there is nothing logically incoherent about physical dynamics without consciousness. (2) follows from the fact that logical possibility just means no contradiction. If we cannot see any contradiction in two propositions being true, then that is defeasible evidence for the logical possibility of both propositions being true.
    - RaftPeople 2y ago
      > if something is conceivable then it is logically possible What does it mean to be "logically possible"? We could conceive of something that is pure garbage due to our lack of knowledge. Something that could never exist due to nature of the universe, but just because we can conceive of it does not mean it's a valid and non-contradictory state for the universe. It's possible it's a valid argument from the perspective that it forces us into the corner of stating one of these two conditions must be true: either p-zombies or consciousness requires attributes to our reality that are beyond our current physical understanding.
root_axis 2y ago
Why is phenomenological subjective experience a thing at all? Unless you're a proponent of panpsychism, we have to ask why living beings have it, but other natural processes do not. From this perspective, it's actually easier to conceive of a world like ours without subjective experience than one with it.
- dragonwriter 2y ago
  > Unless you're a proponent of panpsychism, we have to ask why living beings have it, but other natural processes do not. No, we don't. Because, while an individual may experience it, the conjecture that other things do or do not have it is without exception an unverifiable assumption, not an observed phenomenon which calls for an explanation. > it's actually easier to conceive of a world like ours without subjective experience than one with it. This is demonstrably false, because no experiencer can observe subjective experience other than their own, and, despite that, describing the world in terms of subjective experience occurring in a vast array of other beings beside the speaker is near-universal, to the point that we pathologize not viewing the universe that way.
  - root_axis 2y ago
    > the conjecture that other things do or do not have it is without exception an unverifiable assumption Yes, but ultimately, either they do or they don't, and the default assumption is that they don't, unless you favor panpsychism.
- jstanley 2y ago
  The real problem with the p-zombies thing is why do p-zombies talk about consciousness?. You and I have the experience of talking about being conscious because we have the experience of being conscious in the first place. But for a p-zombie to behave exactly the same as us, it would have to have some other mechanism for talking about being conscious that is not dependent on being conscious. So that would mean that our talking about consciousness can be explained by some mechanism other than our being conscious in the first place! Our experience of consciousness, and our talking about experiencing consciousness, could just happen to be one massive coincidence rather than being causally linked! Doesn't seem likely, ergo no p-zombies. https://www.lesswrong.com/posts/kYAuNJX2ecH2uFqZ9/the-generalized-anti-zombie-principle https://www.lesswrong.com/posts/kYAuNJX2ecH2uFqZ9/the-genera...
nabla9 2y ago
> 4. So, materialism is false. Physicalism is conditionally false. If p-zombies are logically incoherent, the consciousness does not exist. It's an illusion. This is the argument by Daniel Dennet. We are zombies. I mean it's obvious to any physicalist that we don't really feel anything. There is no I, soul, no suffering in a in a rock, peas soup, or a human. It's all physical process.
- tasty_freeze 2y ago
  Dennett was a determinist, but he preferred a compatibilist definition of free will. He didn't want to throw the baby out with the bathwater so he kept the term but defined it to mean what he wanted it to mean. I have no problem with that. I don't use that definition of free will so I say I don't have free will. "There is no I, soul, no suffering in ... a human. " You have an idiosyncratic definition of suffering. If I offer you the option of having a warm bath or having your skin flayed and then be dipped in lemon juice, which would you prefer?
  - nabla9 2y ago
    Free will and the hard problem of consciousness are orthogonal concepts. Completely unconscious automaton can have compatibilist free will and reverse. Compatibilist view does not require consciousness (in hard problem definition). > which would you prefer? Prefer is action, learned habituation response. There is nobody inside to see be aware of it according to Dennet. Simple control system with thermometer controlling heater has preference to homeostasis with certain temperature. Consciousness is illusion according to Dennet. Just because I can verbally express my preferred state does not imply I'm consious.
theptip 2y ago
A simple counter-argument to p-zombies that I like (I first encountered from Yudkowski) is: If there was no conscious experience in this identical p-zombie world, it would be impossible to explain why everybody falsely claims they have conscious experience. If people stop claiming this, then the world is physically different, as people no longer act and produce artifacts such as HN posts discussing the phenomenon. Or, my summary would be: conscious experience is causal, and so you cannot get the same universe-wide effects without it.
- naasking 2y ago
  Not impossible actually. People often claim falsehoods are real, eg. demons, ghosts, deities, etc. If you believe it's possible that p-zombies could generate false beliefs about these other things, then consciousness would just be another falsehood.
  - theptip 2y ago
    You would need some coordinating mechanism to ensure that all the p-zombies have the same hallucination. Including some detailed state machine that takes sense inputs, and processes it to produce the qualia present in each waking moment, plus the valence attributed to each moment of qualia. Since a non-p-zombie can sit down and interrogate the details of their conscious experience, then write a book about it, which others read and agree upon the fine details - I find it hard to come up with a p-zombie substitute that wouldn’t just be consciousness by another name.
    - naasking 2y ago
      > You would need some coordinating mechanism to ensure that all the p-zombies have the same hallucination You mean like talking and writing? As I said, how would p-zombies invent organized religion or other common spiritual beliefs that are false? > Since a non-p-zombie can sit down and interrogate the details of their conscious experience, then write a book about it, which others read and agree upon the fine details First, assuming you think that we're not p-zombies, not everybody agrees on the properties of consciousness even though we presumably have such an introspective ability. Therefore what you describe is a kind of fictional just-so story, and clearly doesn't actually happen in all cases. Second, when there is no fact of the matter as with p-zombies and consciousness, any argument about consciousness only has to be rhetorically persuasive, not factual. Why do so many people agree on the broad properties of ghosts, eg. translucency, pass through physical objects, etc. despite such things not existing? There is no fact of the matter being described, so people just need to like the story being told, or perhaps how it's told. In such a world, Chalmers and other philosophers of consciousness are just persuasive writers that spin a convincing just-so story connecting fictional internal states to real world observations, and people/p-zombies run with it thinking they learned something meaningful. Suffice it to say, I think this is uncomfortably close to our world.
naasking 2y ago
Chalmers' argument is more of an intuition pump to clarify your thinking. If premise 2 seems plausible, then you probably cannot be a physicalist. If you're a die-hard physicalist, then you probably have to deny premise 1 and/or 2.
FrustratedMonky 2y ago
"logically possible world physically identical" "Point 2 is textbook begging the question" -> It is a thought experiment. He is proposing a possible postulate to spur talking about the ideas. It isn't a 'proof'. Just like we don't argue with Schrodinger about the absurdity of a half dead cat.
sireat 2y ago
The thing is we are acting like 99.9% p-zombies for most of our interactions with the world - that is we are acting unconsciosly for most of what we do. The question is where does that subjective 0.01% - the rider on top of the elephant come from? We generally do not pay attention to walking, breathing or brushing teeth and so on. We can do more complex tasks as well once we achieve unconscious mastery in some subject. With proper training we can play chess or tennis ("The Inner Game of Tennis") at a high level, without paying attention. In fact it can be detrimental to think about one's performance. It is the Dennett's "multiple drafts model" - but where does the subjective experience arise when some model is brought to foreground "thread"? Thus allure of Chalmer's zombies. Why not have a 100% zombie? There are many stories of people seemingly being conscious, yet not really. Black out drunks driving home from a bar. Hypoglycemic shock is another example - my wife's diabetic friend was responding seemingly logically and claiming to be conscious, yet she was not and paramedics were barely able to save her. A human being can achieve very high levels on unconscious mastery in multiple subjects. A very tired me gave a remote lecture (on intermediate Python) during Covid where I switched spoken languages mid-lecture and even answered questions in a different language. Meanwhile I was was half asleep and thinking about a different subject matter. I was not really aware of the lecture material - I had given the same lecture many times before - I was on autopilot. Only after watching the Zoom recording I realized what had happened. Thus, are there are some actions that our zombie (unconscious) states unable to produce? Presumably, subjective experience helps in planning future actions. That could be one avenue to explore.
- kkoncevicius 2y ago
  Just wanted to say how much I like your answer. To me one of the bigger puzzles is why people have such different takes on consciousness. To some the idea of p-zombies is immediately clear. To others it is nonsense. But during my conversations about the topic I was never able to explain it adequately to someone sceptical. And from my perspective they (the sceptics) always conflate being conscious with talking, learning, thinking, remembering, etc.
- causal 2y ago
  Good points. Part of my issue with these discussions is the poor vocabulary we have for consciousness. Your comment alone probably touches on several types of consciousness. The kind of consciousness we're experiencing undoubtedly varies greatly by time and circumstance.
mensetmanusman 2y ago
You can’t skip over step 1, this is an axiom. I see more materialists denying they have consciousness and free will. Kind of funny actually.
- tasty_freeze 2y ago
  I skipped point 1 because I don't have a problem with it. I am a materialist until I hear compelling evidence that that is not sufficient. I don't deny we have consciousness, but I don't believe we have libertarian free will. I don't see why that is funny except to people who have never thought about it. Here is an analogy. When playing a video game, the world is fictional and enemies are algorithmic creations. Yet, while playing that game, it is useful (that is, one plays the game better) by accepting the rules of that world and pretending as if the experiences are real at some level. Eg, "This guy is trying to kill me" vs the reality of "a microprocessor is reading state in memory and as a result is rewriting that state and some of that state shows up on my monitor as colored pixels and I'm not in actual danger." Although I intellectually believe I'm an incredibly complex mechanism that is simply letting the laws of physics play out, it is useful while playing the game of life to utilize the evolutionary developed fiction that I do have free will. Here is another intuition pump. Do you believe the weather has a free will, or is it just a physical phenomenon? (presumably the latter) Yet when we talk about the weather, we might say there is a 30% change of rain tomorrow. The reality is it will or it won't rain, but we can't measure the state of the system's initial conditions nor simulate its evolution accurately enough to say exactly what will happen. So we use the convenient fiction that whether it rains or not is statistical. People are too complex that we can't even calculate our own behavior, so it is a convenient fiction to act as if we have free will.
andoando 2y ago
P-zombies is a thought experiment to demonstrate the hard problem of consciousness, it is not, in itself, an argument against materialism. I can certainly imagine a robot that imitates all of human behaviors. If you hit it, it goes "Ow" and retracts, if you ask it if its conscious it says "yes". We can this imagine being created out of our completely physical electrical components, so the question becomes what is the difference between the imitation of consciousness and the consciousness we experience? This is interesting as in this day and age, we can totally imagine building such a robot, yet we'd have a tough time believing it is actually conscious. Now, whether you are a materialist or not depends entirely on whether or not you believe conscious experience like yours can emerge out of physical components. My take on this is: Materialism/physicalism is ill defined and materialism/physicalism and dualism are compatible. We consider completely mysterious properties like energy and now even randomness (things happen one way or another for no reason) as being fundamental physical facts about the universe. Theoretically, how does this differ from saying consciousness is a fundamental physical property? Moreover, you have to consider the fact that the "material" world IS an imagination of the mind. Whatever facts or attributes we assign to being material is limited to the mental facilities of the brain. At the end of the day, the question is, what fundamental facts do we need to explain the observations that we make? I can observe that I feel, see, hear things. Can the fundamental facts of the current physics model explain this? No? Then we must add to it an additional property, making it part of the standard physics model. If you want proof, you must either A. explain how consciousness can emerge out of existing known "material" processes, B. Admit consciousness as a "material" property and define the process by which it combines, reduces, etc. (the combination problem of panpsychism)

codeflo 2y ago

If you believe that what we describe as "consciousness" is emergent from the ideas a material brain develops about itself, then it's in fact not logically possible to have a world that is physically identical to ours yet does not contain consciousness. So indeed, premise 2. sneaks in the conclusion. To illustrate this point, here's an argument with the same structure that would similarly "prove" that gravity doesn't cause things to fall down: 1. In our world, there is gravity and things fall down. 2. There is a logically possible world where there is gravity yet things do not fall down. 3. Therefore, things falling down is a further fact about our world, over and above gravity. 4. So, gravity causing things to fall down is false.

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goatlover 2y ago
But Chalmers doesn't think that approach works, nor any other physicalist attempt to explain consciousness. The problem with what you stated is that you're substituting ideas about consciousness for sensations. And those aren't the same thing. We experience sensations as part of being embodied organisms, and then we think about those sensations.
- codeflo 2y ago
  I’m making an argument about the validity of an argument. A rebuttal to that can never be “but the conclusion is true”.
- tsimionescu 2y ago
  It's quite clear if you approach these things logically that Chalmers doesn't do a lot of thinking before coming up with these arguments. All of his arguments boil down to "if we assume that consciousness is different from everything else, then it's different from everything else". He gets way, way too much attention for someone who is sub mediocre in his reasoning. He also doesn't understand what computation is, even though he often makes confident statements about it. He thinks computation is a subjective process, that something only counts as a computation if someone interprets it as such, which is simply wrong, not a debatable topic. And this is the core of one of his other arguments about why consciousness can't be a computational process.
  - mensetmanusman 2y ago
    There are a number of ways to determine that consciousness is not a computational process. Roger Penrose is a good source on this.
    - tsimionescu 2y ago
      There is not. It's by the far the most likely explanation, and even if you don't agree with that, it is at least completely consistent with everything we know about computation.
      - mensetmanusman 2y ago
        For one, you would have to determine whether physical laws are computational processes. Stephen Wolfram is trying this, but it requires some incredible assumptions.
        2y ago
mistermann 2y ago
> If you believe that what we describe as "consciousness" is emergent from the ideas a material brain develops about itself, then it's in fact not logically possible to have a world that is physically identical to ours yet does not contain consciousness. This sneaks in an implicit axiom: that the brain is not only necessary, but is also sufficient, necessarily, for consciousness (implicitly ruling out some unknown outside, non-materialistic force(s)).
empath75 2y ago
I don't think your point 2 is directly analogous to his point 2. Because a world where things do not fall down is not physically identical to a world in which they don't. I think the point of arguing about p-zombies is this. Do you believe it's possible for a human being to exhibit all the external characteristics of consciousness without an internal conscious experience? And if you believe that's true, then you can posit a world which is physically indistinguishable from our world through any experiment in which consciousness simply does not exist, because, as far as I know, there is no test that can prove that an individual does have an internal consciousness, and isn't merely mimicking it. Most arguments that p-zombies don't exist sort of rely on the internal conscious experience of the person making it, which no one else has access to -- "I have an internal conscious experience of the world, other people are similar to me and so they must also have those experiences." That is _not_ true about a world in which gravity does not exist for obvious reasons. That universe would be very different from ours and easily distinguishible through experiment. I think his point does hinge on whether it's possible for p-zombies to exist, but it's not as silly as you all are making it out to be, and it is not begging the question. I actually think his weakest point is part 3 and 4, because I think mostly the problem is that we don't really have good definitions of consciousness and related concepts let alone a complete physical explanation of their origins, and his whole argument hinges on the fact that we currently don't have a way to test for internal conscious experience, but I think that might not always be true.
- observationist 2y ago
  You experience your own consciousness - your own model of your self, time, and the world as perceived through your physical sensory apparatus. This could give you a probability of 100% certainty of your own consciousness. You're a good skeptic, though, and after much consideration, you decide that, despite absence of evidence to the contrary, you'll allow for 2% uncertainty, since you might be a simulation specifically designed to "feel" conscious, or some other bizarre circumstance. Knowing this, you compare your own experience with reports by others, and find that, despite some startling variety in social and cultural practice, humans all more or less go through life experiencing the world in a way that more or less maps to your own experiences. You find that even Helen Keller, despite her tragic disability, wrote about experiences which you can simulate for yourself. You conclude that if you somehow swapped places with her, she would be able to map the sensory input of your physical sensors to her own experience of the world, and vice versa. This leads you to think that our physical brains are performing a process that models the world, and it does so consistently. After reading up on people's experiences, you also learn that our subjective experiences are constructed, moment by moment, by a combination of these world models, real-time stimulation, abstract feedback loops of conscious and unconscious thinking. The more you read, the more evidence you have of this strange loop being the default case for every instance of a human having a brain and being alive. The Bayesian probability that you are conscious, because of your brain, given all available evidence, approaches 100% certainty. You conclude your brain is more or less the same as anyone else's brain, broadly speaking, and this is supported by the evidence provided by a vast majority of accounts from other similarly brained individuals through all of human history. Since your brain doesn't have a particular difference upon which to pin your experience of consciousness, and the evidence doesn't speak to any need for explanation, Occam's razor leads you to the conclusion that the simplest explanation is also the best. The living human brain is necessary and sufficient for consciousness, and consciousness is the default case for any living human brain. The posterior probability that any given human (with a "normal" living brain) is conscious approaches 100% certainty, unless you can specifically provide evidence to the contrary. Saying "but what if p-zombies exist" makes for a diverting thought experiment, but it's rationally equivalent to saying "but what if little invisible unicorns are the ones actually experiencing things" or "what if we're all in the Matrix and it's a simulation" or "what if we're just an oddly persistent Boltzmann brain in an energetic nebula somewhere in the universe." Without evidence, p-zombies are a plot device, not a legitimate rational launching off point for theorizing about anything serious. Humans are conscious. We have neural correlates, endless recorded evidence, all sorts of second hand reporting which can compare and contrast our own first hand experiences and arrive at rational conclusions. Insisting on some arbitrary threshold of double blind, first hand, objective replicable evidence is not necessary, and even a bit shortsighted and silly, since the thing we are talking about cannot be directly shared or communicated. At some point, we'll be able to map engrams and share conscious experience directly between brains using BCI, and the translation layer between individuals will be studied, and we'll have chains of double blinded, replicable experiments that give us visibility into the algorithms of conscious experience. Without direct interfaces to the brain and a robust knowledge of neural operation, we're left with tools of abstract reasoning. There's no good reason for p-zombies - they cannot exist, given the evidence, so we'd be better served by thinking about things that are real.
mensetmanusman 2y ago
Your Step 2 is so off as an analogy, it’s possible you don’t understand Chalmer’s point.
- chr1 2y ago
  What is Chalmers saying then? As i understand he is saying that there can be a world where conciousness does not exist, but all the possible physical experiments cannot distinguish between that world and our world. But that simply means the conciousness he is looking for has absolutely no consequence, and therefore his point has no value...
  - mensetmanusman 2y ago
    He is saying that the person in the Chinese room doesn’t understand Chinese.
    - chr1 2y ago
      How is this related to the 2nd point in OP's comment? The whole Chinese room argument is based merely on a misinterpretation of computentionalist/physicalist argument. Of course the computer or person who executes the program does not understand Chinese, they are just performing arithmetic operations, the entity understanding Chinese is the program itself, not the medium on which the program runs.

patrickmay 2y ago

Well and succinctly put. One would have to be a philosopher to be willing to consider p-zombies further.

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RaftPeople 2y ago
Some of the arguments I've read by philosophers seem like they are focusing on pure logic to prove a point or find weakness in another, but the linkage between those logic stmts and reality don't always seem to be considered. It's almost like they are purely focused on symbolic logic, even if the stmts and symbols don't truly map to reality unambiguously, or without contradictions.
empath75 2y ago
I actually think it's worth asking the question if these advanced AIs are a kind of p-zombie.
- Filligree 2y ago
  P-zombies are supposed to be physically identical to humans. They’re problematic because they lack consciousness, yet mysteriously talk about it anyway — among other reasons. Advanced AI is definitely not physically identical to humans, and there’s a well understood reason why they might talk about consciousness despite lacking it which doesn’t apply to p-zombies.
  - empath75 2y ago
    I'm not sure that being physically identical to humans is a necessary characteristic of a p-zombie for anything important. If you can produce an ai which _acts in every observable way as if it were conscious_ without any actual consciousness that would indicate that p-zombies are possible. The current generations of AI don't qualify, but I can see how to get there from here.

amelius 2y ago

> it imagines a world which is physically identical to ours but consciousness is different there So a world where people discuss consciousness but where it does not exist? That sounds very implausible.

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sornen 2y ago

Chalmers in point 2 is not saying to imagine such a world, but that such a world is logically possible. Chalmers gives as an example of a logical impossibility a male vixen since it is contradictory. He states "... a flying telephone is conceptually coherent, if a little out of the ordinary, so a flying telephone is logically possible. Nevertheless, that zombies are logically possible, may be begging the question, that consciousness is non physical.

tasty_freeze 2y ago
I'm still missing the point, I guess, as I don't think the question is logically possible. One might as well say: it is logically possible to have a universe where the physics are identical to our present world, except the core of the Sun is chocolate... therefore fusion can't be the explanation for why our Sun radiates so much energy. Getting back to the zombies, presuming there could be a zombie clone of me which is indistinguishable from the real me but it isn't conscious is one that needs far more support than just asserting it. I've heard people try to explain: well, imagine if a powerful computer was simulating you in every respect, that would be a p-zombie. But that is question begging, as it presumes that such a creature wouldn't be conscious. I feel the same way about Searle's Chinese Room -- the power of the argument is there only if you have already decided that consciousness is mystical.
tsimionescu 2y ago
But it's not logically possible if consciousness is a material process, a consequence of computation in the human brain (and potentially other places). So you can't prove that consciousness is not materialistic by assuming it's not materialistic.
idiotsecant 2y ago
I have known some pretty vixen-y males...

goatlover 2y ago

No, you have to take that argument in context of his other arguments against physical explanations for consciousness. What he's saying is that the physical facts do not adequately account for conscious experiences, which is why we can conceive of a universe physically identical lacking consciousness. Why he (and some other philosophers) think this is so is part of their larger arguments.

Ukv 2y ago
> which is why we can conceive of a universe physically identical lacking consciousness I can conceive of it about as well as I can conceive of an identical universe lacking the Internet. Both seem like fairly direct logical contradictions, slightly disguised by referring to concepts that we generally think about more abstractly rather than their physical composition.
tsimionescu 2y ago
If you examine all of his arguments, they all end up in the same place. He assumes that consciousness is not necessary for human-like or even animal-like intelligence, and he works from there back to the same conclusion.

hackinthebochs 2y ago

> Point 2 is textbook begging the question: it imagines a world which is physically identical to ours but consciousness is different there. It's not begging the question. He gives reasons for (2) that support the premise. That the premise essentially leads inexorably to (4) is a feature of the argument structure, not a bug. You have to engage with his reasons for (2) in determining whether or not the argument succeeds.

tasty_freeze 2y ago
Can you give an outline of some of that evidence? I haven't read source Chalmers, just other people's discussions of the topic (including the article that is the subject of this thread).
- hackinthebochs 2y ago
  The argument is roughly that (1) we can conceive of the physical dynamics of this world occurring without any associated consciousness, (2) if something is conceivable then it is logically possible, (3) It is logically possible that the physical dynamics of this world occur without any associated consciousness. (1) is supported by noticing that all our explanations of physical dynamics appeals to other physical dynamics. We do not need to mention consciousness or qualitative anything to derive any of the physical dynamics we observe in this world. Thus there is nothing logically incoherent about physical dynamics without consciousness. (2) follows from the fact that logical possibility just means no contradiction. If we cannot see any contradiction in two propositions being true, then that is defeasible evidence for the logical possibility of both propositions being true.
  - RaftPeople 2y ago
    > if something is conceivable then it is logically possible What does it mean to be "logically possible"? We could conceive of something that is pure garbage due to our lack of knowledge. Something that could never exist due to nature of the universe, but just because we can conceive of it does not mean it's a valid and non-contradictory state for the universe. It's possible it's a valid argument from the perspective that it forces us into the corner of stating one of these two conditions must be true: either p-zombies or consciousness requires attributes to our reality that are beyond our current physical understanding.

root_axis 2y ago

Why is phenomenological subjective experience a thing at all? Unless you're a proponent of panpsychism, we have to ask why living beings have it, but other natural processes do not. From this perspective, it's actually easier to conceive of a world like ours without subjective experience than one with it.

dragonwriter 2y ago
> Unless you're a proponent of panpsychism, we have to ask why living beings have it, but other natural processes do not. No, we don't. Because, while an individual may experience it, the conjecture that other things do or do not have it is without exception an unverifiable assumption, not an observed phenomenon which calls for an explanation. > it's actually easier to conceive of a world like ours without subjective experience than one with it. This is demonstrably false, because no experiencer can observe subjective experience other than their own, and, despite that, describing the world in terms of subjective experience occurring in a vast array of other beings beside the speaker is near-universal, to the point that we pathologize not viewing the universe that way.
- root_axis 2y ago
  > the conjecture that other things do or do not have it is without exception an unverifiable assumption Yes, but ultimately, either they do or they don't, and the default assumption is that they don't, unless you favor panpsychism.
jstanley 2y ago
The real problem with the p-zombies thing is why do p-zombies talk about consciousness?. You and I have the experience of talking about being conscious because we have the experience of being conscious in the first place. But for a p-zombie to behave exactly the same as us, it would have to have some other mechanism for talking about being conscious that is not dependent on being conscious. So that would mean that our talking about consciousness can be explained by some mechanism other than our being conscious in the first place! Our experience of consciousness, and our talking about experiencing consciousness, could just happen to be one massive coincidence rather than being causally linked! Doesn't seem likely, ergo no p-zombies. https://www.lesswrong.com/posts/kYAuNJX2ecH2uFqZ9/the-generalized-anti-zombie-principle https://www.lesswrong.com/posts/kYAuNJX2ecH2uFqZ9/the-genera...

nabla9 2y ago

> 4. So, materialism is false. Physicalism is conditionally false. If p-zombies are logically incoherent, the consciousness does not exist. It's an illusion. This is the argument by Daniel Dennet. We are zombies. I mean it's obvious to any physicalist that we don't really feel anything. There is no I, soul, no suffering in a in a rock, peas soup, or a human. It's all physical process.

tasty_freeze 2y ago
Dennett was a determinist, but he preferred a compatibilist definition of free will. He didn't want to throw the baby out with the bathwater so he kept the term but defined it to mean what he wanted it to mean. I have no problem with that. I don't use that definition of free will so I say I don't have free will. "There is no I, soul, no suffering in ... a human. " You have an idiosyncratic definition of suffering. If I offer you the option of having a warm bath or having your skin flayed and then be dipped in lemon juice, which would you prefer?
- nabla9 2y ago
  Free will and the hard problem of consciousness are orthogonal concepts. Completely unconscious automaton can have compatibilist free will and reverse. Compatibilist view does not require consciousness (in hard problem definition). > which would you prefer? Prefer is action, learned habituation response. There is nobody inside to see be aware of it according to Dennet. Simple control system with thermometer controlling heater has preference to homeostasis with certain temperature. Consciousness is illusion according to Dennet. Just because I can verbally express my preferred state does not imply I'm consious.

theptip 2y ago

A simple counter-argument to p-zombies that I like (I first encountered from Yudkowski) is: If there was no conscious experience in this identical p-zombie world, it would be impossible to explain why everybody falsely claims they have conscious experience. If people stop claiming this, then the world is physically different, as people no longer act and produce artifacts such as HN posts discussing the phenomenon. Or, my summary would be: conscious experience is causal, and so you cannot get the same universe-wide effects without it.

naasking 2y ago
Not impossible actually. People often claim falsehoods are real, eg. demons, ghosts, deities, etc. If you believe it's possible that p-zombies could generate false beliefs about these other things, then consciousness would just be another falsehood.
- theptip 2y ago
  You would need some coordinating mechanism to ensure that all the p-zombies have the same hallucination. Including some detailed state machine that takes sense inputs, and processes it to produce the qualia present in each waking moment, plus the valence attributed to each moment of qualia. Since a non-p-zombie can sit down and interrogate the details of their conscious experience, then write a book about it, which others read and agree upon the fine details - I find it hard to come up with a p-zombie substitute that wouldn’t just be consciousness by another name.
  - naasking 2y ago
    > You would need some coordinating mechanism to ensure that all the p-zombies have the same hallucination You mean like talking and writing? As I said, how would p-zombies invent organized religion or other common spiritual beliefs that are false? > Since a non-p-zombie can sit down and interrogate the details of their conscious experience, then write a book about it, which others read and agree upon the fine details First, assuming you think that we're not p-zombies, not everybody agrees on the properties of consciousness even though we presumably have such an introspective ability. Therefore what you describe is a kind of fictional just-so story, and clearly doesn't actually happen in all cases. Second, when there is no fact of the matter as with p-zombies and consciousness, any argument about consciousness only has to be rhetorically persuasive, not factual. Why do so many people agree on the broad properties of ghosts, eg. translucency, pass through physical objects, etc. despite such things not existing? There is no fact of the matter being described, so people just need to like the story being told, or perhaps how it's told. In such a world, Chalmers and other philosophers of consciousness are just persuasive writers that spin a convincing just-so story connecting fictional internal states to real world observations, and people/p-zombies run with it thinking they learned something meaningful. Suffice it to say, I think this is uncomfortably close to our world.

naasking 2y ago

Chalmers' argument is more of an intuition pump to clarify your thinking. If premise 2 seems plausible, then you probably cannot be a physicalist. If you're a die-hard physicalist, then you probably have to deny premise 1 and/or 2.

FrustratedMonky 2y ago

"logically possible world physically identical" "Point 2 is textbook begging the question" -> It is a thought experiment. He is proposing a possible postulate to spur talking about the ideas. It isn't a 'proof'. Just like we don't argue with Schrodinger about the absurdity of a half dead cat.

sireat 2y ago

The thing is we are acting like 99.9% p-zombies for most of our interactions with the world - that is we are acting unconsciosly for most of what we do. The question is where does that subjective 0.01% - the rider on top of the elephant come from? We generally do not pay attention to walking, breathing or brushing teeth and so on. We can do more complex tasks as well once we achieve unconscious mastery in some subject. With proper training we can play chess or tennis ("The Inner Game of Tennis") at a high level, without paying attention. In fact it can be detrimental to think about one's performance. It is the Dennett's "multiple drafts model" - but where does the subjective experience arise when some model is brought to foreground "thread"? Thus allure of Chalmer's zombies. Why not have a 100% zombie? There are many stories of people seemingly being conscious, yet not really. Black out drunks driving home from a bar. Hypoglycemic shock is another example - my wife's diabetic friend was responding seemingly logically and claiming to be conscious, yet she was not and paramedics were barely able to save her. A human being can achieve very high levels on unconscious mastery in multiple subjects. A very tired me gave a remote lecture (on intermediate Python) during Covid where I switched spoken languages mid-lecture and even answered questions in a different language. Meanwhile I was was half asleep and thinking about a different subject matter. I was not really aware of the lecture material - I had given the same lecture many times before - I was on autopilot. Only after watching the Zoom recording I realized what had happened. Thus, are there are some actions that our zombie (unconscious) states unable to produce? Presumably, subjective experience helps in planning future actions. That could be one avenue to explore.

kkoncevicius 2y ago
Just wanted to say how much I like your answer. To me one of the bigger puzzles is why people have such different takes on consciousness. To some the idea of p-zombies is immediately clear. To others it is nonsense. But during my conversations about the topic I was never able to explain it adequately to someone sceptical. And from my perspective they (the sceptics) always conflate being conscious with talking, learning, thinking, remembering, etc.
causal 2y ago
Good points. Part of my issue with these discussions is the poor vocabulary we have for consciousness. Your comment alone probably touches on several types of consciousness. The kind of consciousness we're experiencing undoubtedly varies greatly by time and circumstance.

mensetmanusman 2y ago

You can’t skip over step 1, this is an axiom. I see more materialists denying they have consciousness and free will. Kind of funny actually.

tasty_freeze 2y ago
I skipped point 1 because I don't have a problem with it. I am a materialist until I hear compelling evidence that that is not sufficient. I don't deny we have consciousness, but I don't believe we have libertarian free will. I don't see why that is funny except to people who have never thought about it. Here is an analogy. When playing a video game, the world is fictional and enemies are algorithmic creations. Yet, while playing that game, it is useful (that is, one plays the game better) by accepting the rules of that world and pretending as if the experiences are real at some level. Eg, "This guy is trying to kill me" vs the reality of "a microprocessor is reading state in memory and as a result is rewriting that state and some of that state shows up on my monitor as colored pixels and I'm not in actual danger." Although I intellectually believe I'm an incredibly complex mechanism that is simply letting the laws of physics play out, it is useful while playing the game of life to utilize the evolutionary developed fiction that I do have free will. Here is another intuition pump. Do you believe the weather has a free will, or is it just a physical phenomenon? (presumably the latter) Yet when we talk about the weather, we might say there is a 30% change of rain tomorrow. The reality is it will or it won't rain, but we can't measure the state of the system's initial conditions nor simulate its evolution accurately enough to say exactly what will happen. So we use the convenient fiction that whether it rains or not is statistical. People are too complex that we can't even calculate our own behavior, so it is a convenient fiction to act as if we have free will.

andoando 2y ago

P-zombies is a thought experiment to demonstrate the hard problem of consciousness, it is not, in itself, an argument against materialism. I can certainly imagine a robot that imitates all of human behaviors. If you hit it, it goes "Ow" and retracts, if you ask it if its conscious it says "yes". We can this imagine being created out of our completely physical electrical components, so the question becomes what is the difference between the imitation of consciousness and the consciousness we experience? This is interesting as in this day and age, we can totally imagine building such a robot, yet we'd have a tough time believing it is actually conscious. Now, whether you are a materialist or not depends entirely on whether or not you believe conscious experience like yours can emerge out of physical components. My take on this is: Materialism/physicalism is ill defined and materialism/physicalism and dualism are compatible. We consider completely mysterious properties like energy and now even randomness (things happen one way or another for no reason) as being fundamental physical facts about the universe. Theoretically, how does this differ from saying consciousness is a fundamental physical property? Moreover, you have to consider the fact that the "material" world IS an imagination of the mind. Whatever facts or attributes we assign to being material is limited to the mental facilities of the brain. At the end of the day, the question is, what fundamental facts do we need to explain the observations that we make? I can observe that I feel, see, hear things. Can the fundamental facts of the current physics model explain this? No? Then we must add to it an additional property, making it part of the standard physics model. If you want proof, you must either A. explain how consciousness can emerge out of existing known "material" processes, B. Admit consciousness as a "material" property and define the process by which it combines, reduces, etc. (the combination problem of panpsychism)