Zombies - totally not scary at all.
As an evolutionary philosopher who looks at the entire history of evolution and only sees evidence for physical, natural, non-supernatural things in the universe, I read the following lines from Philosophy Now's article The Zombie Threat to a Science of Mind and I began to get worried:
Many look forward to the day when physicists will resolve these niggling issues and present the public with the Holy Grail of science: a Grand Unified Theory of everything. The hope of many philosophically-inclined scientists and scientifically-enthused philosophers is that this theory will explain the existence and nature of everything there is. Let us call this kind of view ‘physicalism’. Physicalism is a grand and ambitious project, but there is a thorn in its side: consciousness. The qualities each of us encounters in our conscious experience – the feeling of pain, the sensations of biting into a lemon, what it’s like to see red – stubbornly refuse to be incorporated into the physicalist’s all-encompassing vision of the universe. Consciousness seems to be the one bit of left-over magic that refuses to be physicalised. And it’s all the fault of the zombies.
Did that make me worried about the fate of physicalism? Heck no! Instead, it made me worried about the field of philosophy yet again. Let's take a look at this week's thought experiment and then hunt these zombies down.
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Lucia lived in a town where the lights were on, but nobody was ever home. She lived among zombies.
This was not as scary as it might sound. These zombies were not the flesh-eating ghouls of horror films. They looked and behaved just like you and I. They even had exactly the same physiology as you and I. But there was one key difference: they had no minds. If you pricked them they would say "ouch" and wince, but they felt no pain. If you "upset" them they would cry or get angry, but there would be no inner turmoil. If you played them soothing music they would appear to enjoy it, but in their minds they would hear nothing. On the outside, they were ordinary humans, but on the inside, nothing was going on.
This made them easy to get along with. It was easy to forget that they didn't have inner lives as she did, since they spoke and behaved just like ordinary people and that included references to how they felt or what they thought. Visitors to the town would also fail to notice anything strange. Even when Lucia let them in on the secret, they refused to believe her.
"How do you know that they have no minds?" they would ask. "How do you know that other people do?" would be Lucia's reply. That usually shut them up.
Baggini, J., The Pig That Wants to Be Eaten, 2005, p. 277.
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Baggini didn't cite any sources for this problem, but the greatest populariser of the idea, David Chalmers, gives us this brief history of philosophical zombies:
As far as I know, the first paper in the philosophical literature to talk at length about zombies under that name was Robert Kirk's "Zombies vs. Materialists" in Mind in 1974, although Keith Campbell's 1970 book Body and Mind talks about an "imitation-man" which is much the same thing, and the idea arguably goes back to Leibniz's "mill" argument. After Kirk's paper, there was hardly any explicit discussion of zombies in the philosophical literature for a long time (although there was quite a lot on "absent qualia", i.e. functional zombies). When I wrote my 1993 Ph.D. thesis, in which zombies played a central role, there was hardly anything out there. But for one reason or another, zombies have risen from the grave in the last few years; and they turn out to be unaccountably well-represented on the web.
Unaccountable is right!
Now, it's mildly fun to go down the path of exploring consciousness and trying to prove that zombies can't possibly exist and therefore prove that consciousness is only a physical phenomenon. I thought about using this post to look into medical conditions where people already act sort of like zombies and see how that might inform us. If you look into the psychological literature on topics such as unconscious phenomena, sleepwalking, automatism, highway hypnosis or, dissociation, you find a whole host of actions where people appear to exhibit normal behaviour but they have no memory of doing so. They acted, as it were, with their "lights out." Such behaviours point to at least the transient existence of real life zombies, but because these activities actually all have traceable physical causes or effects, they do not produce philosophical zombies. The subjects never show loss of consciousness without some corresponding change in physical activities.
All of that would lead me to believe there is a strong case to be made for the physical nature of consciousness, but still, can we really rule out ALL possibilities of philosophical zombies? No. Of course not. But that's okay. There are an infinite number of things that we can't rule out as impossible (gods, flying teacups, spaghetti monsters, etc., etc.), but we don't fret about each and every one of them. Chalmers, however, thinks this one is different for some reason. Going back to the Philosophy Now article on this subject, we see why in this summary of Chalmers' points. He says:
We can break down this zombie argument against physicalism as follows:
1. Philosophical zombies are possible.
2. Therefore, human brain states could possibly exist without human conscious states.
3. Therefore, human brain states cannot be identical with human conscious states.
4. For physicalism to be true, human brain states must be identical with human conscious states.
5. Therefore, physicalism is false.
Seriously?? Premise number one has to be allowed because we don't have a full definition of consciousness yet and anything is possible to discover when we don't know the future. That doesn't mean physicalism is false though. It just means physicalism may be false. Conclusion 3, must be rewritten "Therefore, human brain states*may not* be identical with human conscious states." We just don't know yet.
Once again, we see philosophers getting bogged down due to an inherent contradiction with their epistemology. Chalmers starts his argument by saying that our epistemological uncertainty allows zombies to maybe just possibly exist. That's fine. We cannot know what the future will bring. But then he wants to use that inherent uncertainty to arrive at an epistemologically certain statement that "physicalism is false." But if Chalmers were to play by the same epistemological rules from start to finish, he would only ever get to the conclusion that physicalism is possible. Just like zombies. Except, you know, there's all the evidence in the universe so far for physicalism.
I'm not exactly the first person to point this out. Too many physicalists like Daniel Dennett have gone after Chalmers by claiming his physiological zombies are logically incoherent and thus impossible, but that's a fools errand while the science is in its infancy. When you look at those competing arguments for the possibility or impossibility of philosophical zombies, it becomes obvious that both sides are using circular / begging the question fallacies. To claim zombies are possible is just claiming that consciousness isn't physical. To claim zombies are impossible is just claiming consciousness is only physical. So you can't use zombies to say anything new about consciousness. Richard Brown showed this, by proposing "the existence of "zoombies", which are creatures nonphysically identical to people in every way and lack phenomenal consciousness. If zoombies existed, they would refute dualism because they would show that consciousness is not nonphysical, i.e., is physical. Paralleling the argument from Chalmers: It's conceivable that zoombies exist, so it's possible they exist, so dualism is false."
That's very clever, and it hints at the fact that philosophical zombies are neither TRUE nor FALSE yet, which is why the form of Chalmers' argument can be used in either direction. Cognitive scientist Stevan Harnad managed to point this out specifically in his 1995 article, "Why and how we are not zombies." He wrote:
This is ordinary scientific underdetermination: You can always predict and explain a small body of data in lots of ways, most or all of which have nothing to do with reality. But as you predict and explain more and more data, your degrees of freedom shrink and your theory gets more powerful and general. The hope, in all areas of science, is that when it is complete, and predicts and explains all observable data, then your theory will have converged on reality; it will be the true theory of the way things are. [But] it might not be.
So if Brown and Harnad refuted the argument so well, why are zombies still a hot topic? Maybe it's because their arguments didn't follow up with a call for a revolution in epistemology (like I have done), which ultimately allows philosophers to just keep on playing games. I guess that's why philosophers aren't scientists—because they enjoy speculating about the unknown and fighting about what may or may not be there while the evidence is gathered by others. I often find that tedious and pointless though. How many similar conundrums could be imagined about dark matter, abiogenisis, life on other planets, or any of the other great mysteries science has identified but so far been unable to solve? One can imagine an infinite variety of debates about these, all just waiting to fill up philosophical journals. But none of these merely potential occurrences have any weight whatsoever to actually affect our current knowledge. They are observations with an n of zero. So to me, there's really no need to continue running around moaning about them. That'd just be brainless.
Many look forward to the day when physicists will resolve these niggling issues and present the public with the Holy Grail of science: a Grand Unified Theory of everything. The hope of many philosophically-inclined scientists and scientifically-enthused philosophers is that this theory will explain the existence and nature of everything there is. Let us call this kind of view ‘physicalism’. Physicalism is a grand and ambitious project, but there is a thorn in its side: consciousness. The qualities each of us encounters in our conscious experience – the feeling of pain, the sensations of biting into a lemon, what it’s like to see red – stubbornly refuse to be incorporated into the physicalist’s all-encompassing vision of the universe. Consciousness seems to be the one bit of left-over magic that refuses to be physicalised. And it’s all the fault of the zombies.
Did that make me worried about the fate of physicalism? Heck no! Instead, it made me worried about the field of philosophy yet again. Let's take a look at this week's thought experiment and then hunt these zombies down.
--------------------------------------------------
Lucia lived in a town where the lights were on, but nobody was ever home. She lived among zombies.
This was not as scary as it might sound. These zombies were not the flesh-eating ghouls of horror films. They looked and behaved just like you and I. They even had exactly the same physiology as you and I. But there was one key difference: they had no minds. If you pricked them they would say "ouch" and wince, but they felt no pain. If you "upset" them they would cry or get angry, but there would be no inner turmoil. If you played them soothing music they would appear to enjoy it, but in their minds they would hear nothing. On the outside, they were ordinary humans, but on the inside, nothing was going on.
This made them easy to get along with. It was easy to forget that they didn't have inner lives as she did, since they spoke and behaved just like ordinary people and that included references to how they felt or what they thought. Visitors to the town would also fail to notice anything strange. Even when Lucia let them in on the secret, they refused to believe her.
"How do you know that they have no minds?" they would ask. "How do you know that other people do?" would be Lucia's reply. That usually shut them up.
Baggini, J., The Pig That Wants to Be Eaten, 2005, p. 277.
---------------------------------------------------
Baggini didn't cite any sources for this problem, but the greatest populariser of the idea, David Chalmers, gives us this brief history of philosophical zombies:
As far as I know, the first paper in the philosophical literature to talk at length about zombies under that name was Robert Kirk's "Zombies vs. Materialists" in Mind in 1974, although Keith Campbell's 1970 book Body and Mind talks about an "imitation-man" which is much the same thing, and the idea arguably goes back to Leibniz's "mill" argument. After Kirk's paper, there was hardly any explicit discussion of zombies in the philosophical literature for a long time (although there was quite a lot on "absent qualia", i.e. functional zombies). When I wrote my 1993 Ph.D. thesis, in which zombies played a central role, there was hardly anything out there. But for one reason or another, zombies have risen from the grave in the last few years; and they turn out to be unaccountably well-represented on the web.
Unaccountable is right!
Now, it's mildly fun to go down the path of exploring consciousness and trying to prove that zombies can't possibly exist and therefore prove that consciousness is only a physical phenomenon. I thought about using this post to look into medical conditions where people already act sort of like zombies and see how that might inform us. If you look into the psychological literature on topics such as unconscious phenomena, sleepwalking, automatism, highway hypnosis or, dissociation, you find a whole host of actions where people appear to exhibit normal behaviour but they have no memory of doing so. They acted, as it were, with their "lights out." Such behaviours point to at least the transient existence of real life zombies, but because these activities actually all have traceable physical causes or effects, they do not produce philosophical zombies. The subjects never show loss of consciousness without some corresponding change in physical activities.
All of that would lead me to believe there is a strong case to be made for the physical nature of consciousness, but still, can we really rule out ALL possibilities of philosophical zombies? No. Of course not. But that's okay. There are an infinite number of things that we can't rule out as impossible (gods, flying teacups, spaghetti monsters, etc., etc.), but we don't fret about each and every one of them. Chalmers, however, thinks this one is different for some reason. Going back to the Philosophy Now article on this subject, we see why in this summary of Chalmers' points. He says:
We can break down this zombie argument against physicalism as follows:
1. Philosophical zombies are possible.
2. Therefore, human brain states could possibly exist without human conscious states.
3. Therefore, human brain states cannot be identical with human conscious states.
4. For physicalism to be true, human brain states must be identical with human conscious states.
5. Therefore, physicalism is false.
Seriously?? Premise number one has to be allowed because we don't have a full definition of consciousness yet and anything is possible to discover when we don't know the future. That doesn't mean physicalism is false though. It just means physicalism may be false. Conclusion 3, must be rewritten "Therefore, human brain states*may not* be identical with human conscious states." We just don't know yet.
Once again, we see philosophers getting bogged down due to an inherent contradiction with their epistemology. Chalmers starts his argument by saying that our epistemological uncertainty allows zombies to maybe just possibly exist. That's fine. We cannot know what the future will bring. But then he wants to use that inherent uncertainty to arrive at an epistemologically certain statement that "physicalism is false." But if Chalmers were to play by the same epistemological rules from start to finish, he would only ever get to the conclusion that physicalism is possible. Just like zombies. Except, you know, there's all the evidence in the universe so far for physicalism.
I'm not exactly the first person to point this out. Too many physicalists like Daniel Dennett have gone after Chalmers by claiming his physiological zombies are logically incoherent and thus impossible, but that's a fools errand while the science is in its infancy. When you look at those competing arguments for the possibility or impossibility of philosophical zombies, it becomes obvious that both sides are using circular / begging the question fallacies. To claim zombies are possible is just claiming that consciousness isn't physical. To claim zombies are impossible is just claiming consciousness is only physical. So you can't use zombies to say anything new about consciousness. Richard Brown showed this, by proposing "the existence of "zoombies", which are creatures nonphysically identical to people in every way and lack phenomenal consciousness. If zoombies existed, they would refute dualism because they would show that consciousness is not nonphysical, i.e., is physical. Paralleling the argument from Chalmers: It's conceivable that zoombies exist, so it's possible they exist, so dualism is false."
That's very clever, and it hints at the fact that philosophical zombies are neither TRUE nor FALSE yet, which is why the form of Chalmers' argument can be used in either direction. Cognitive scientist Stevan Harnad managed to point this out specifically in his 1995 article, "Why and how we are not zombies." He wrote:
This is ordinary scientific underdetermination: You can always predict and explain a small body of data in lots of ways, most or all of which have nothing to do with reality. But as you predict and explain more and more data, your degrees of freedom shrink and your theory gets more powerful and general. The hope, in all areas of science, is that when it is complete, and predicts and explains all observable data, then your theory will have converged on reality; it will be the true theory of the way things are. [But] it might not be.
So if Brown and Harnad refuted the argument so well, why are zombies still a hot topic? Maybe it's because their arguments didn't follow up with a call for a revolution in epistemology (like I have done), which ultimately allows philosophers to just keep on playing games. I guess that's why philosophers aren't scientists—because they enjoy speculating about the unknown and fighting about what may or may not be there while the evidence is gathered by others. I often find that tedious and pointless though. How many similar conundrums could be imagined about dark matter, abiogenisis, life on other planets, or any of the other great mysteries science has identified but so far been unable to solve? One can imagine an infinite variety of debates about these, all just waiting to fill up philosophical journals. But none of these merely potential occurrences have any weight whatsoever to actually affect our current knowledge. They are observations with an n of zero. So to me, there's really no need to continue running around moaning about them. That'd just be brainless.
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