So the philosophical zombie is a person who reports a completely normal set of sensations and emotions, while actually having none of them, right? I think zombies would be a ridiculous way to build an organism. Much easier to build something that reported the truth, rather than build a perfect liar. I could imagine such a thing, but that doesn’t say much about whether a zombie could exist. I read a lot of science fiction and can imagine six impossible things before breakfast.
The point is not that zombies exist. The point is that “it’s a ridiculous way to build an organism” is not a physical law and actual physical laws don’t seem to specify that our world is not a zombie-world. For anything else from science fiction you can in principle check corresponding physical equation and conclude that this thing is impossible. How do you do it for the difference between our world and zombie-world?
The point is that “it’s a ridiculous way to build an organism” is not a physical law
It kind of is. An organism evolved to be a perfect liar about having consciousness has to have a different causal history than a organism evolved to have consciousness and tell about it so the physical laws that provided these histories have to be different too.
Also, notice that what you are talking here isn’t a classical PZ as originally stated: an entity that does everything that a conscious human does for exactly the same reasons up to every elemental particle in the brain but still lacks consciousness. It’s a “zombie master” scenario where there are some other causes that makes the zombie pretend that it has consciousness. Confusion between this two scenarios is common and misleading.
Well, looks like I misremebered what a P-zombie is. I think the notion of “an entity that does everything a human being does for exactly the same reasons […] but lacks consciousness” is completely absurd. Obviously someone who lacks consciousness is asleep or comatose. I don’t see how someone who’s walking around, talking about past experience, reporting sensations, etc, could fail to be conscious.
This has always seemed perfectly obvious to me, but it’s not obvious to other highly sensible people. Could it be they’re experiencing some extra thing in their sensations, that says “this could be dispensed with, you would have the same sensations, but then you wouldn’t be conscious.”? If so, I’m here to tell you the good news that your brain is lying about that.
Well, it’s fascinating the extent to which we each find the other’s position completely unrealistic. I think we’re getting closer to a crux, which is good.
I presume you’re not talking about Cotard’s delusion, which can result in people walking around and talking while claiming they’re dead. That’s just a delusion.
We measure comatoseness with the Glasgow Coma Scale, which ranges from 0 (eyes closed, no speech, motionless even under painful stimuli) to 15 (normal). You’re talking about people who feel comatose while still scoring 15 on the Glasgow coma scale? How can someone be comatose and still respond to stimuli, report memories, and perform voluntary action? It seems implicit in the definition of comatose that that’s impossible. It may not be a physical law, but it’s certainly a medical one.
(For the record, I don’t find your position completely unrealistic).
How can someone be comatose and still respond to stimuli, report memories, and perform voluntary action?
Not “be comatose”—“feel comatose”. No one is disputing medical knowledge—it certainly works in our world. But, regardless of how much it contradicts usual science heuristics, how unlikely it is to actually work like that in reality—can you imagine that the world could be different in only “feeling” aspect? Where zombie-you is looking at the blue sky and doesn’t feel like you in the same situation, but feels like you imagine feeling when comatose. If you don’t immediately reject that idea as implausible, do you have a concept for it at all?
If you do, then the problem is that, regardless of how absurd it is heuristically, actual laws of physics don’t seem to specify that our world is not a zombie-world.
Crucially, in a world with only these zombies- where no-one who has ever had qualia—the zombies start arguing about the existing of qualia. (Otherwise, this would be a way to distinguish zombies from people using a physical test)
That’s just unimaginably weird. In my experience of feeling comatose, having no vision and not laying down any memories were notable features. There’s no way I can experience a blue sky while simultaneously not experiencing it. Nor can I report on my recent experiences while being unable to form memories.
See, this is why I think qualia are a thing on top of sensation. You experience qualia, and feel that without them, something vital would be missing, and it would be like feeling comatose. And I’m here to tell you that life without qualia is pretty sweet.
Zombie-you wouldn’t experience blue sky—they would always only experience being comatose. They would behave like you behave down to the level of neurons and atoms, but they would not experience what you experience when you are seeing a blue sky. I understand that this may sound unlikely and, yes, weird, but what’s so hard to imagine? You just imagine feeling comatose, nothing more. Sure you can imagine feeling angry, when in reality you would feel sad—how is this different?
That is, from my point of view, asking me to have two contradictory experiences at once: being normal and being comatose. And you’re going to say, “not being comatose, feeling comatose.“ And I will say, I can’t imagine acting awake and also feeling comatose. Let‘s look at a particular feature of coma: not being able to stand upright. I would feel like I was unable to stand, while in fact standing up whenever appropriate. And this is not some crazy delusion— in fact my brain is operating normally. No, I can’t imagine what that would feel like. We‘re both intelligent persons, not trying to be deceptive. And yet we have a large difference in what we can imagine ourselves being like when we introspect. I claim this is due to an actual difference in the structure of our cognition, best summed up as “I don’t have qualia, you do.”
That would feel like being comatose. Again, I could understand if you said “it’s unlikely to happen”, but I still don’t understand how not being able to even imagine it would work. Some similar things are even can happen in the real world: you can not consciously see anything, don’t feel like you can move your hand, but still move your hand. You can just extrapolate from this to not feeling anything. You can say that feelings about being comatose are delusional in that case.
Or, can you imagine that it’s not you that experiences blue sky—your copy does—when actual you are a comatose ghost? Like, you don’t even need to have qualia to imagine qualia—they can be modeled by just adding a node to your casual graph that includes neurons or whatever. You can do that with your models, right?
Your disagreement is mirrored almost exactly in Yudkowsky’s post Zombies Redacted. The crucial point (as mentioned also in Hastings’ sister comment) is that the thought experiment breaks down as soon as you consider the zombies making just the same claims about consciousness as we do, while not actually having any coherent reason for making such claims (as they are defined to not have consciousness in the first place). I guess you can imagine, in some sense, a scenario like that, but what’s the point of imagining a hypothetical set of physical laws that lack internal coherence?
Zombies being wrong is not a problem for experiment’s coherence—their reasons for making claims about consciousness are just terminated on the level of physical description. The point is that the laws of physics don’t seem to prohibit a scenario like this: for other imagined things you can in principle run the calculations and say “no, evolution on earth would not produce talking unicorns”, but where is the part that says that we are not zombies? There are reasons to not believe in zombies and more reasons to not believe in epiphenomenalism, like “it would be coincidence for us to know about epiphenomenal consciousness”, but the problem is that these reasons seem to be outside of physical laws.
what’s the point of imagining a hypothetical set of physical laws that lack internal coherence?
I don’t think they lack internal coherence; you haven’t identified a contradiction in them. But one point of imagining them is to highlight the conceptual distinction between, on the one hand, all of the (in principle) externally observable features or signs of consciousness, and, on the other hand, qualia. The fact that we can imagine these coming completely apart, and that the only ‘contradiction’ in the idea of zombie world is that it seems weird and unlikely, shows that these are distinct (even if closely related) concepts.
This conceptual distinction is relevant to questions such as whether a purely physical theory could ever ‘explain’ qualia, and whether the existence of qualia is compatible with a strictly materialist metaphysics. I think that’s the angle from which Yudkowsky was approaching it (i.e. he was trying to defend materialism against qualia-based challenges). My reading of the current conversation is that Signer is trying to get Carl to acknowledge the conceptual distinction, while Carl is saying that while he believes the distinction makes sense to some people, it really doesn’t to him, and his best explanation for this is that some people have qualia and some don’t.
So the philosophical zombie is a person who reports a completely normal set of sensations and emotions, while actually having none of them, right? I think zombies would be a ridiculous way to build an organism. Much easier to build something that reported the truth, rather than build a perfect liar. I could imagine such a thing, but that doesn’t say much about whether a zombie could exist. I read a lot of science fiction and can imagine six impossible things before breakfast.
The point is not that zombies exist. The point is that “it’s a ridiculous way to build an organism” is not a physical law and actual physical laws don’t seem to specify that our world is not a zombie-world. For anything else from science fiction you can in principle check corresponding physical equation and conclude that this thing is impossible. How do you do it for the difference between our world and zombie-world?
It kind of is. An organism evolved to be a perfect liar about having consciousness has to have a different causal history than a organism evolved to have consciousness and tell about it so the physical laws that provided these histories have to be different too.
Also, notice that what you are talking here isn’t a classical PZ as originally stated: an entity that does everything that a conscious human does for exactly the same reasons up to every elemental particle in the brain but still lacks consciousness. It’s a “zombie master” scenario where there are some other causes that makes the zombie pretend that it has consciousness. Confusion between this two scenarios is common and misleading.
Well, looks like I misremebered what a P-zombie is. I think the notion of “an entity that does everything a human being does for exactly the same reasons […] but lacks consciousness” is completely absurd. Obviously someone who lacks consciousness is asleep or comatose. I don’t see how someone who’s walking around, talking about past experience, reporting sensations, etc, could fail to be conscious.
This has always seemed perfectly obvious to me, but it’s not obvious to other highly sensible people. Could it be they’re experiencing some extra thing in their sensations, that says “this could be dispensed with, you would have the same sensations, but then you wouldn’t be conscious.”? If so, I’m here to tell you the good news that your brain is lying about that.
A p zombie is supposed to lack qualia , not consciousness in the medical.sense.
Absurd why? What physical law prevents walking around, talking about past experience and reporting sensations from feeling like being comatose?
Well, it’s fascinating the extent to which we each find the other’s position completely unrealistic. I think we’re getting closer to a crux, which is good.
I presume you’re not talking about Cotard’s delusion, which can result in people walking around and talking while claiming they’re dead. That’s just a delusion.
We measure comatoseness with the Glasgow Coma Scale, which ranges from 0 (eyes closed, no speech, motionless even under painful stimuli) to 15 (normal). You’re talking about people who feel comatose while still scoring 15 on the Glasgow coma scale? How can someone be comatose and still respond to stimuli, report memories, and perform voluntary action? It seems implicit in the definition of comatose that that’s impossible. It may not be a physical law, but it’s certainly a medical one.
(For the record, I don’t find your position completely unrealistic).
Not “be comatose”—“feel comatose”. No one is disputing medical knowledge—it certainly works in our world. But, regardless of how much it contradicts usual science heuristics, how unlikely it is to actually work like that in reality—can you imagine that the world could be different in only “feeling” aspect? Where zombie-you is looking at the blue sky and doesn’t feel like you in the same situation, but feels like you imagine feeling when comatose. If you don’t immediately reject that idea as implausible, do you have a concept for it at all?
If you do, then the problem is that, regardless of how absurd it is heuristically, actual laws of physics don’t seem to specify that our world is not a zombie-world.
Crucially, in a world with only these zombies- where no-one who has ever had qualia—the zombies start arguing about the existing of qualia. (Otherwise, this would be a way to distinguish zombies from people using a physical test)
That’s just unimaginably weird. In my experience of feeling comatose, having no vision and not laying down any memories were notable features. There’s no way I can experience a blue sky while simultaneously not experiencing it. Nor can I report on my recent experiences while being unable to form memories.
See, this is why I think qualia are a thing on top of sensation. You experience qualia, and feel that without them, something vital would be missing, and it would be like feeling comatose. And I’m here to tell you that life without qualia is pretty sweet.
Zombie-you wouldn’t experience blue sky—they would always only experience being comatose. They would behave like you behave down to the level of neurons and atoms, but they would not experience what you experience when you are seeing a blue sky. I understand that this may sound unlikely and, yes, weird, but what’s so hard to imagine? You just imagine feeling comatose, nothing more. Sure you can imagine feeling angry, when in reality you would feel sad—how is this different?
That is, from my point of view, asking me to have two contradictory experiences at once: being normal and being comatose. And you’re going to say, “not being comatose, feeling comatose.“ And I will say, I can’t imagine acting awake and also feeling comatose.
Let‘s look at a particular feature of coma: not being able to stand upright. I would feel like I was unable to stand, while in fact standing up whenever appropriate. And this is not some crazy delusion— in fact my brain is operating normally. No, I can’t imagine what that would feel like.
We‘re both intelligent persons, not trying to be deceptive. And yet we have a large difference in what we can imagine ourselves being like when we introspect. I claim this is due to an actual difference in the structure of our cognition, best summed up as “I don’t have qualia, you do.”
That would feel like being comatose. Again, I could understand if you said “it’s unlikely to happen”, but I still don’t understand how not being able to even imagine it would work. Some similar things are even can happen in the real world: you can not consciously see anything, don’t feel like you can move your hand, but still move your hand. You can just extrapolate from this to not feeling anything. You can say that feelings about being comatose are delusional in that case.
Or, can you imagine that it’s not you that experiences blue sky—your copy does—when actual you are a comatose ghost? Like, you don’t even need to have qualia to imagine qualia—they can be modeled by just adding a node to your casual graph that includes neurons or whatever. You can do that with your models, right?
Your disagreement is mirrored almost exactly in Yudkowsky’s post Zombies Redacted. The crucial point (as mentioned also in Hastings’ sister comment) is that the thought experiment breaks down as soon as you consider the zombies making just the same claims about consciousness as we do, while not actually having any coherent reason for making such claims (as they are defined to not have consciousness in the first place). I guess you can imagine, in some sense, a scenario like that, but what’s the point of imagining a hypothetical set of physical laws that lack internal coherence?
Zombies being wrong is not a problem for experiment’s coherence—their reasons for making claims about consciousness are just terminated on the level of physical description. The point is that the laws of physics don’t seem to prohibit a scenario like this: for other imagined things you can in principle run the calculations and say “no, evolution on earth would not produce talking unicorns”, but where is the part that says that we are not zombies? There are reasons to not believe in zombies and more reasons to not believe in epiphenomenalism, like “it would be coincidence for us to know about epiphenomenal consciousness”, but the problem is that these reasons seem to be outside of physical laws.
I don’t think they lack internal coherence; you haven’t identified a contradiction in them. But one point of imagining them is to highlight the conceptual distinction between, on the one hand, all of the (in principle) externally observable features or signs of consciousness, and, on the other hand, qualia. The fact that we can imagine these coming completely apart, and that the only ‘contradiction’ in the idea of zombie world is that it seems weird and unlikely, shows that these are distinct (even if closely related) concepts.
This conceptual distinction is relevant to questions such as whether a purely physical theory could ever ‘explain’ qualia, and whether the existence of qualia is compatible with a strictly materialist metaphysics. I think that’s the angle from which Yudkowsky was approaching it (i.e. he was trying to defend materialism against qualia-based challenges). My reading of the current conversation is that Signer is trying to get Carl to acknowledge the conceptual distinction, while Carl is saying that while he believes the distinction makes sense to some people, it really doesn’t to him, and his best explanation for this is that some people have qualia and some don’t.