Zombies
10.1. p–Zombie
A p-zombie (philosophical zombie) is generally defined as “a being that is physically identical to a normal human except that it lacks qualia and conscious experiences” [1-5]. However, although this definition is philosophically possible, it is not certain that it is also physically tenable. If qualia and conscious experiences have physical effects, there might be something else that is physically associated with them disappears or changes in the being too when it lacks qualia and conscious experiences. This may render the term “physically identical to a normal human except that it lacks qualia and conscious experiences” physically impossible and make such a defined p-zombie impossible to exist physically. If we want to do an experiment to see whether a being with qualia and conscious experiences and a being without qualia and conscious experiences are physically identical or not, we must use the definition that all the beings involved can definitely exist physically. In doing so, we must take the possibility that qualia and conscious experiences may have physical effects into account. Otherwise, the definition might define something that is physically impossible to exist, and the result that is derived from the experiment involving this impossible entity will not be applicable to the physical world. Therefore, the appropriate definition must instead be “a p-zombie is a being that is physically identical to a normal human except that it lacks qualia and conscious experiences and their effects”. Whether qualia’s and conscious experiences’ effects exist or not is to be proved by separate investigations.
This is similar to the scenario that we define that “a p-zombie is a being that is physically identical to a normal human except that it lacks a pineal gland”. Again, although this definition is literally possible, it is not physically possible. Because a pineal gland has physical effects, when a being lacks a pineal gland, it will lack the pineal gland’s hormone and its physical effects. This renders the term “physically identical to a normal human except that it lacks a pineal gland” physically impossible – the defined entity cannot physically exist. The definition that is physically applicable has to be “a p-zombie is a being that is physically identical to a normal human except that it lacks a pineal gland and pineal gland’s effects”. These definitions can be summarized in the following equations:
A human
= a being with the pineal gland and pineal gland’s effects … (1)
A p–zombie (literal definition) = A human – pineal gland
= a being with pineal gland’s effects but without the pineal gland … (2)
(physically impossible, pineal gland’s effects cannot occur without the pineal gland)
A p–zombie (physical definition) = A human – pineal gland – pineal gland’s effects
= a being without the pineal gland and pineal gland’s effects … (3)
(physically possible)
If we compare a human (1) with a p-zombie (literal definition) (2), they will be identical except that the p-zombie does not have the pineal gland, everything else (including the pineal gland’s effects in the p-zombie, who has no pineal gland) is the same. So, they will behave identically. It can thus be concluded that the world of p-zombies and the world of humans are behaviorally identical (although this cannot be true in the present world due to advanced medical technology that can reveal the absence of the pineal gland [such as MRI, CT scan, brain autopsy, or brain surgery] and differentiate a p-zombie from a human, it could be true in the primitive world because, due to the lack of advanced medical technology, the lack of pineal gland in the p-zombies would have been unnoticeable and thus virtually without physical consequences). However, this conclusion is true only literally but not physically because a p-zombie as defined by the literal definition is physically impossible. Such a p-zombie cannot really exist, and neither can the world of p-zombies. So, the conclusion that the world of p-zombies and the world of humans are behaviorally identical must be treated as a literal conclusion, not a physical conclusion. This conclusion does not have physical applications in the real world.
On the other hand, if we compare a human (1) with a p-zombie (physical definition) (3), there will be different in the lack of pineal gland and pineal gland’s effects. Even if we grant that just the lack of the concealed tiny pineal gland in the head does not have any physical effects, the pineal gland’s hormonal effects have significant physical effects that cannot be assumed to be null, and the lack of it definitely has physical consequences. So, the p-zombie that lacks the pineal gland and pineal gland’s effects will behave differently from the human. Evidently, the conclusion will be that the world of p-zombies and that of humans are behaviorally different. This is the case in the real world.
In the cases of qualia and conscious experience, the situation is the same. In the case of qualia, just replace “pineal gland” in the above equations with qualia:
A human
= a being with qualia and qualia’s effects … (1)
A p–zombie (philosophical definition) = A human – qualia
= a being with qualia’s effects but without qualia … (2)
(physically impossible if qualia’s effects do exist; they cannot occur without qualia)
A p–zombie (physical definition) = A human – qualia – qualia effects
= a being without qualia and qualia’s effects … (3)
(physically possible)
If we compare a human (1) with a p-zombie (philosophical definition) (2), they will be identical except that the p-zombie does not have qualia, everything else is the same. So, they will behave identically. The conclusion will thus be that the world of p-zombies and the world of humans are behaviorally identical. However, although this is certainly true philosophically, it is not certain that it is physically applicable. If qualia’s effects do exist, a p-zombie by this philosophical definition will be physically impossible to exist (because qualia’s effects without qualia are not physically possible). This conclusion, which may involve a physically impossible entity, thus has no conclusive physical meaning.
On the other hand, if we compare a human (1) with a p-zombie (physical definition) (3), they will be identical except that the p-zombie does not have qualia and qualia’s effects. If qualia’s physical effects exist, they will occur in the human, but not in the p-zombie. The p-zombie, who lacks qualia’s effects, will behave differently from the human, who has qualia’s effects. So, in the real world, p-zombies (physical definition) may behave differently from humans. And the conclusion will be that the world of p-zombies (physical definition) may be different from that of humans. Whether the p-zombies behave differently from the humans and the world of p-zombies is different from that of humans depends on whether qualia’s effects exist or not. This will be discussed later.
The discussion is the same in the case of conscious experience. Just replace qualia in the above discussion with conscious experience.
At this point, it should be noted that one may believe and assert that qualia and conscious experiences are inert epiphenomena and do not have any physical effects, so they can be compared by using the philosophical definition, and the result will also be true physically. However, using an inappropriate definition is not a correct way of doing a scientific experiment, even if it is a thought one, and can be misleading. Also, if one is committed to the belief that qualia and conscious experiences are inert epiphenomena and do not have any physical effects, then it is no use making the physical comparison between the human and the p-zombie – they are physically identical by the definition and the belief already. Because by definition, the difference between a human and a p-zombie is qualia and conscious experiences, if qualia and conscious experiences do not have any physical effects, then the difference between a human and a p-zombie is physically null – that is, a human and a p-zombie have same physical effects. Stating in equations:
A human – a p-zombie = qualia and conscious experience (by definition) … (1)
Qualia and conscious experience = no physical effects (by belief) … (2)
A human – a p-zombie = no physical effects = 0 (physically) … from (1) & (2)
A human = a p-zombie (physically)
Thus, by the definition and belief, a human and a p-zombie are already identical physically, and there is no use in doing thought experiments examining different physical effects in physically identical entities. This is like comparing an ordinary computer with an n-computer, which is a computer with a name called by a human but not registered in the computer’s system. Because such names do not have any physical effects on computer functions, ordinary computers and n-computers will function identically and the world of ordinary computers and that of n-computers will be physically identical. Undoubtedly, everyone knows that they are physically identical entities, and no one will spend time doing thought experiments examining different physical effects between them. But do qualia not have physical effects on humans as names do not have physical effects on computers?
Actually, this problem has been discussed in details in Chapter 5 and 6, and it has been proven that qualia and conscious experience are not epiphenomena (section 5.3.) and do have some physical effects (section 5.4. and 6.4). Thus, qualia and conscious experiences to humans are not like names to computers, and the above belief (that qualia and conscious experiences are inert epiphenomena and do not have any physical effects) is not correct. Therefore, the philosophical definition is not physically tenable, and the result of thought experiments using philosophical definition is not physically valid.
In conclusion, we have to be careful how we define entities. If we define them philosophically or literally, the results pertaining to the definition will be valid only imaginarily in those domains and cannot be claimed to be true in reality. But if we define them physically, the results pertaining to the definition will be valid in the physical domain and can be claimed to be true in reality.
Now let’s compare a human with a p-zombie (physical definition) to see what the differences between the two are.
Figure 10.1 Human vs. p-Zombie Perception
Consider what happens when a human and a p-zombie see a tiger (Figure 10.1). The early neural events in their visual pathways from the eyes to the cortical areas just prior to the cortical areas for perception are exactly the same. But once perception areas begin to function, further events are different. In the p-zombie, there will be a visual perception of the tiger, but this occurs without a quale and conscious experience, like an image registration in the motherboard of a present-day computer. In the human, in addition to the perception like the one that happens in the p-zombie, a visual quale of a tiger and a conscious experience of the quale occur in his mind. Some specific neural processes that are not present in the p-zombie must be functioning to create this visual quale and conscious experience because the visual quale and the conscious experience cannot happen by themselves (Theorem I: A mental process is part of a neural process). These specific neural processes will have some effects on other neural processes. They may cause more intense fear, more alertness, more sympathetic stimulation, etc., and additional or different behaviors will occur in the human. Thus, a human is physically and behaviorally different from a p-zombie. A world of p-zombies is, therefore, physically and behaviorally different form that of humans. And it can be concluded generally that a world with no qualia and conscious experiences is physically different from a world with qualia and conscious experiences.
This can be more obvious if we consider this matter in the opposite way. A present-day computer does certainly not have conscious experiences of any quale that may occur in their circuits because there are no circuits built to do this specific function (i.e., no circuits to consciously experience any quale that may occur). A conscious experience of a quale is a phenomenon with additional information, and it needs an additional circuit to manage this additional information. A present-day computer thus needs an additional circuit to do this function. Therefore, all functions else being the same, a computer that can function to have conscious experiences of qualia must have an additional circuit and will thus be physically and functionally different from computers that cannot function to have conscious experiences of qualia.
10.2. Lying zombie
A lying zombie or a confabulating zombie is a hypothetical being that is physically identical to a normal human except that it lacks qualia and conscious experiences, yet it claims that it has both phenomena and it can discuss and talk about them in details and comprehensively like us [6-8]. Also, the world of lying zombies will have some zombies that are interested in qualia and conscious experience and discuss them seriously as we do. The world of lying zombies is thus identical to the world of human beings.
But is it possible that such lying zombies exist? The evidence is that it is not. The arguments against the existence of lying zombies are as follows:
- If lying zombies do not have qualia of and conscious experiences of vision, sound, emotion, etc. but lie that they do, then why do they not lie that they have qualia of and conscious experiences of blood levels of oxygen, sodium, hormones, etc. or of echolocation, electroreception, magnetoreception, etc., of which they do not have qualia and conscious experiences either? Why do they lie that they have qualia of and conscious experiences of only the kinds of qualia and conscious experiences that we have?
- Why do lying zombies not lie about other things too; why do they select to lie only having qualia? If lying zombies do not have qualia and conscious experiences but lie that they do, then why do that not lie that they have other mental phenomena that they do not really have either? For example, they could lie that they also have mental phenomena called qualax, qualor, or others that are indescribable to us who do not have these mental phenomena. Why do they specifically lie only that they have qualia, which are the very phenomena that we have?
- The most important reason is: how can a lying zombie think and talk about something that never happens to it and that it does not have information about? How can a world of lying zombies start discussing things that never occur to them and continue to discuss those things seriously? If something never happens to zombies, they cannot have information about that thing and cannot start talking about that thing at all, not to mention continue discussing it seriously like us. This is also true for us: we cannot start talking about and continue discussing qualia of the blood level of sodium, magnetoreception, qualax, qualor, or other things that we do not have information about.
Let’s analyze this problem physically. Consider a being A, which is a lying zombie. When a vision and a sound enter its brain’s neural processes, because qualia and conscious experiences do not occur, what happens in the zombie is only the perception of the vision and the sound. It certainly can tell that they are different information. But if it is asked what it feels like to see or hear those sensations, it will not be able to understand what the question means because “what it feels like to see or hear” does not happen in it and it does not have information about “what it feels like to see or hear” to process (to think about, to talk about, to discuss, etc.). It will naturally ask what we mean by that question.
Now consider a being B, which is a normal human. When a vision and a sound enter its brain’s neural processes, qualia and conscious experiences occur, and the human will have the conscious awareness and experiences of the qualia’s occurrence and of what the qualia are like occurring. These are additional phenomena with additional information that occurs in the human’s brain but not in the zombie’s. When the human is asked what it feels like to see or hear those sensations, although he may not be able to answer it clearly, he will understand what the question means because “what it feels like to see or hear” happens in him/her and because he/she has information about them to process (to think about, to talk about, to discuss, etc.).
In conclusion, perception without qualia and conscious experiences has different information from perception with qualia and conscious experiences. A being with the former perception will not have the information of the latter perception and will not be able to discuss, think about, or talk about qualia and conscious experiences, which are the information that it does not have. Lying zombies are impossible, and the world of lying zombies is not possible either.
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References
- Chalmers DJ. Consciousness and its place in nature. In: Chalmers DJ, editor. Philosophy of mind: Classical and contemporary readings. Oxford: Oxford University Press; 2002. ISBN-13: 978-0195145816 ISBN-10: 019514581X. Retrieved 2017 Sep 20 from http://consc.net/papers/nature.html
- Gennaro RJ. Consciousness. Internet Encyclopedia of Philosophy. Retrieved 2017 Apr 18 from http://www.iep.utm.edu/consciou/
- Kirk R. Zombies. Zalta EN, editor. The Stanford Encyclopedia of Philosophy (Summer 2015 Edition). Retrieved 2017 Apr 10 from https://plato.stanford.edu/archives/sum2015/entries/zombies/
- Tye M. Qualia. Zalta EN, editor. The Stanford Encyclopedia of Philosophy (Winter 2017 Edition). Retrieved 2018 Jan 05 from https://plato.stanford.edu/archives/win2017/entries/qualia/
- Qualia. Wikipedia. 2017 Mar 6. Retrieved 2017 Apr 5 from https://en.wikipedia.org/w/index.php?title=Qualia&direction=prev&oldid=776191840
- Nintil. P-zombies are still undead. Nintil. 2016 Jul 10, 2016. Retrieved 2018 Ar 16 from https://nintil.com/2016/07/10/p-zombies-are-still-undead/
- Reddit, Philosophy. Retrieved 2018 Apr 16 from https://www.reddit.com/r/philosophy/comments/23v25w/how_could_a_philosophical_zombie_discuss/
- Skeptiko-forum. Retreived 2018 Apr 16 from http://www.skeptiko-forum.com/threads/are-philosophical-zombies-possible.1049/
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