It's an interesting conversation you guys are having. Philosophical zombies have always been a major sticking point for me in questions about consciousness... ie basically why are we not PZs? It's very interesting to see you @polymath257 saying you don't think they're a coherent concept... I'm not sure either way really, but they certainly seem paradoxical in some ways, which might indeed mean that they are incoherent.
Taking a PZ to mean a being that has no phenomenal consciousness despite having the same brain structure as one with consciousness. Ie just to be clear, I'm not talking about a lack of consciousness in the sense of deprived consciousness through structural differences or damage etc, but rather a brain that has all the usual neural correlates of consciousness, but no phenomenal consciousness, if such a thing is possible. That's what I personally mean when I'm talking about PZs. This sort of PZ would be completely physically indistinguishable... and thus undetectable - in all objectively observable respects, be they behaviour or brain structure - from another like being with phenomenal consciousness... such beings would for instance talk about emotional states and consciousness just as much as their phenomenally conscious equivalents, and do so because their brains still represent exactly the same information and processes, including motor outputs leading to verbal reports etc.
The main paradox for me, and what really boggles my mind, is if phenomenal consciousness is basically a mirror (or emergent property or whatever) of let's call it 'neural consciousness' (ie the neural correlates of consciousness)... if both are identical but viewed from different perspectives... just two sides of the same coin... (which is how I see it, and it looks like you do similarly as well)... then it's curious if we would treat them differently depending on if they had or did not have phenomenal consciousness. And intuitively I think we would treat them differently because (ie a non-PZ or PZ interacting with a hypothetically confirmed PZ (even though there'd be no way to confirm it, but just for argument's sake say it was confirmed somehow)) we feel empathy and sympathy for others based on not wanting them to feel pain, but feeling pain we intuitively see (or at least I see) as a purely phenomenal aspect of consciousness... ie sure there are distributed physical and neural correlates of that consciousness, and thus that pain... our brain state that is mirrored (for want of a better term) in/by consciousness, but nonetheless, I cannot intuitively look at those distributed processes in isolation, which is what the concept of a pZ is about, and feel the same sort of emotional response to it, in the sense of empathy/sympathy, as I would for imagining a phenomenally conscious state.
So that's basically the main crux of the problem for me... though it may just turn out to be sloppy thinking, I don't know. All that I have described above may be incoherent and/or circular in places... it's just the rabbit hole my mind goes into on these issues... so it might be inherent in that, under closer analysis, why the concept of a PZ is incoherent, if it is. So basically I'm leaving it as an open question whether it even makes sense, but ultimately it doesn't really matter and is only a philosophical problem, because like I said if such a PZ existed there'd be no way to detect it, so given our own experience of our own consciousness and the fact that we can reasonably assume that is equally the case for other similar beings, there's no reason to assume the presence of PZs in our reality, and in the presence of any such doubt on that score - such as for very small/simple organisms, it makes much more sense I think, from an ethical point of view, to err on the side of assuming consciousness, even when it's not as intuitively obvious that there would be consciousness. So basically, it's not that I think there are PZs out there, because personal experience obviously tells me otherwise (even if you have no way of knowing if I'm a PZ or not
), but just that given that we do have phenomenal consciousness, why do we have it when it seems superfluous and with no causal power? (ie looking at it from a physical determinism point of view, obviously referring to the neural side as being physically determined (albeit with whatever quantum implications, but whatever they may be, I don't think they affect the thrust of what I'm saying)). I'm not expecting an answer here, just detailing my thought process on all this (though feel free to add your thoughts if you're interested)... the way I'm picturing PZs might just turn out to be incoherent... or not... but it's interesting seeing someone who does see them as incoherent... basically whatever way it goes, it's all food for thought 
Taking a PZ to mean a being that has no phenomenal consciousness despite having the same brain structure as one with consciousness. Ie just to be clear, I'm not talking about a lack of consciousness in the sense of deprived consciousness through structural differences or damage etc, but rather a brain that has all the usual neural correlates of consciousness, but no phenomenal consciousness, if such a thing is possible. That's what I personally mean when I'm talking about PZs. This sort of PZ would be completely physically indistinguishable... and thus undetectable - in all objectively observable respects, be they behaviour or brain structure - from another like being with phenomenal consciousness... such beings would for instance talk about emotional states and consciousness just as much as their phenomenally conscious equivalents, and do so because their brains still represent exactly the same information and processes, including motor outputs leading to verbal reports etc.
The main paradox for me, and what really boggles my mind, is if phenomenal consciousness is basically a mirror (or emergent property or whatever) of let's call it 'neural consciousness' (ie the neural correlates of consciousness)... if both are identical but viewed from different perspectives... just two sides of the same coin... (which is how I see it, and it looks like you do similarly as well)... then it's curious if we would treat them differently depending on if they had or did not have phenomenal consciousness. And intuitively I think we would treat them differently because (ie a non-PZ or PZ interacting with a hypothetically confirmed PZ (even though there'd be no way to confirm it, but just for argument's sake say it was confirmed somehow)) we feel empathy and sympathy for others based on not wanting them to feel pain, but feeling pain we intuitively see (or at least I see) as a purely phenomenal aspect of consciousness... ie sure there are distributed physical and neural correlates of that consciousness, and thus that pain... our brain state that is mirrored (for want of a better term) in/by consciousness, but nonetheless, I cannot intuitively look at those distributed processes in isolation, which is what the concept of a pZ is about, and feel the same sort of emotional response to it, in the sense of empathy/sympathy, as I would for imagining a phenomenally conscious state.
So that's basically the main crux of the problem for me... though it may just turn out to be sloppy thinking, I don't know. All that I have described above may be incoherent and/or circular in places... it's just the rabbit hole my mind goes into on these issues... so it might be inherent in that, under closer analysis, why the concept of a PZ is incoherent, if it is. So basically I'm leaving it as an open question whether it even makes sense, but ultimately it doesn't really matter and is only a philosophical problem, because like I said if such a PZ existed there'd be no way to detect it, so given our own experience of our own consciousness and the fact that we can reasonably assume that is equally the case for other similar beings, there's no reason to assume the presence of PZs in our reality, and in the presence of any such doubt on that score - such as for very small/simple organisms, it makes much more sense I think, from an ethical point of view, to err on the side of assuming consciousness, even when it's not as intuitively obvious that there would be consciousness. So basically, it's not that I think there are PZs out there, because personal experience obviously tells me otherwise (even if you have no way of knowing if I'm a PZ or not
), but just that given that we do have phenomenal consciousness, why do we have it when it seems superfluous and with no causal power? (ie looking at it from a physical determinism point of view, obviously referring to the neural side as being physically determined (albeit with whatever quantum implications, but whatever they may be, I don't think they affect the thrust of what I'm saying)). I'm not expecting an answer here, just detailing my thought process on all this (though feel free to add your thoughts if you're interested)... the way I'm picturing PZs might just turn out to be incoherent... or not... but it's interesting seeing someone who does see them as incoherent... basically whatever way it goes, it's all food for thought
