| Functionalism and Absent Qualia, by Anthony Peter Iannini, 2001 |
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Essay Overview from 05.02.2011:
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If I had to summarize, briefly, what this lengthy essay is about it is basically thus: There is no way to verify whether or not you are a philosophical zombie or whether you are not precisely because the belief that you have phenomenal consciousness does not necessarily entail that you actually posses phenomenal consciousness. One can believe there is some property X in one's private experience but, without a way to check it against anything, there is no way to know what it is in the first place that is being referred to.
In other words, from the first-person perspective of a philosophical zombie, there is no difference between a "normal" human and a philosophical zombie human even though, from an objective perspective, we assume we know that there is a difference. But this is only an assumption and can only ever, principally, be an assumption. This is one way of demonstrating the "Beetle in the Box" example posed by the philosopher Ludwig Wittgenstein [1889-1951]. It is in assuming that there is a difference at all that the key flaw in functionalist objector's arguments is exposed.
We can not refer to a private thing in public yet we make the mistake of talking about phenomenal consciousness as if we all know exactly what we are referring to when, in fact, it is potentially nothing or exactly like we think it is but, and this is crucial: there is no way to verify one's or another's possession of phenomenal consciousness or qualia in principle, ever, at all, period. Therefore, all theories of mind will leave this feature out given that theories are publically available arrangements of public symbols, as in sentences with words, etc.
This points to the impossibility of knowing the internal experience of any other being and, to a strange extent, there is an impossibility in knowing one's own state of consciousness. This, I think, reveals that there is no objective or public referent to the term "consciousness" except in a certain meaning that points to the neuroscientific meaning of being awake or aware. Being awake or aware does not describe, in any way, the deeper meaning of consciousness that can not be described objectively or publically. This essay is basically a complicated and intricate way of demonstrating Wittgenstein's "beetle in the box" analogy and what I have here stated in this introduction.
This dense initial summary of this long essay may be rather impenetrable or require the reader have more background in the subject at hand. The first half of this essay is devoted to educating the reader as to the supposed meaning of qualia, a qual, or phenomenal consciousness. The latter half of this essay attempts to show the futility of attributing phenomenal consciousness to others or even to one's own self given that no one really knows what this term refers to because it is not a publically or objectively available referent.
1. Introduction: Functionalism, one of the most prominent contemporary philosophical and psychological theories of mind, has been objected to on the grounds that it does not incorporate or capture the nature of phenomenal consciousness.1 This problem is more generally indicative of the perceived failure of objective theories of mind, which describe cognition in information-processing terms, to capture the quality of subjective experience.
In what follows, I will demonstrate that certain arguments which attempt to show the possibility of missing phenomenal consciousness in functionalist descriptions of the mind are successful. Usually, the success of such arguments is thought to show a deficiency in functionalist accounts of the mind. However, I will claim the opposite. I shall argue that functionalism, and any objective theory of mind, is safe from arguments which rely on the possibility of missing or absent phenomenal consciousness.
It is my thesis that (i) arguments, which successfully show that functionalist mental descriptions allow for the possibility of absent phenomenal consciousness, bring up serious skeptical issues concerning third-person and first-person attributions of phenomenal consciousness and therefore, (ii) such arguments against functionalism do not imply the falsity of functionalism. In order to prepare my case, I will, in section 2, discuss and define functionalism, the philosophical theory of mind within which my argument will be formulated. Then, in section 3, I will introduce and examine the concept of 'phenomenal consciousness'.
This will be followed by a presentation of certain views which take phenomenal consciousness to be inessential to completed functionalist descriptions of the mind. Following these exegetical sections, in section 4, I will formulate my first argument. This initial argument will assert the possible existence of beings that do not possess phenomenal consciousness yet believe that they possess phenomenal consciousness.
After defending my argument for the possible existence of such beings from various objections to the possibility of such beings in the latter part of section 4, I will, in section 5, present clear reasons why deep skepticism concerning our epistemic justification for third-person and first-person attributions of phenomenal consciousness is warranted. The conclusions of section 5 will lead to my final analysis of the problem with functionalism and qualia in section 6, where I shall interpret my conclusion's impact on functionalism.
2. Functionalism: Functionalism's theoretical scope and influence has affected developments not only in philosophy, but in psychology, neuroscience, and computer science. Because my argument deals intimately with functionalist construals of the mind, I will attempt to define and explain functionalism in two ways. Firstly, I will examine the historical precursors to functionalist theories of mind; behaviorist and mind-brain identity theories. Secondly, I shall provide an analysis and formulation of the essential characteristics of the functionalist paradigm that are relevant to my argument.
2.1 Behaviorism as a Theoretical Precursor to Functionalism: The first formulations of functionalism were the product of quasi-behavioristic principles. Behaviorism is the view that takes verifiable behavioral data as yielding lawful relations between the inputs (or stimuli) and outputs (or responses) of a given system. Scientific behaviorism grew from the rejection of introspection as a scientifically viable research method in psychology and is clearly expressed in the following words by John B. Watson, "Psychology. . .is a purely objective experimental branch of natural science. Its theoretical goal is the prediction and control of behavior" (1913, p. 158).
It was the goal of scientific behaviorism to formulate all human and animal behavior in terms of reflexes and various conditioned responses, the latter being supposedly able to account for learning and memory. Philosophical behaviorism was initially formulated by the logical positivists (such as Carnap, Ayer, and Hempel) who argued that mentalistic expressions were synonymous with some set of objectively verifiable statements that capture behavioristic dispositions and physiological mechanisms.
Generally, behaviorism attempts to explain behavior by attributing behavioral dispositions to systems and entities. For example, in behavioristic terms, to say that "x is flammable" is equivalent to saying, "if x were exposed to a flame, then x would burn". Such simplistic behavioral attributions become much more difficult in the case of complex cognitive systems such as humans. Take, for example, the following statement, "S believes there are no lions in France".
How are we to derive a complete list of S's behavioral dispositions based on this belief? We could say that, "If S is asked whether or not she believes there are lions in France, then she would respond negatively". But, this is to assume that S is not intending to mislead, and that S understands the language in which the question is posited, and many other, perhaps infinite, possibilities. In order to highlight the salient difficulties in behavioristic explanations, consider the following example, which I label 'BE', from Jaegwon Kim:
BE: If Sally desires that fresh air be let in and believes that by opening the window she can have that happen, she will open the window (1996, p. 34-35).
But, as Kim points out, can we tell if BE is true? What if Sally also believes that by opening the window, she will also let in loud noises or a flock of hungry pigeons? We could reformulate BE to include these other beliefs. But, we could again question this reformulation and it too would require additional suppositions concerning Sally's intentional (beliefs, desires, etc.) states and concerning her environment. BE would certainly be false if the window in the example was out of Sally's reach or was sealed shut.
The problem with BE and other behavioristic explanations in general is that they are always defeasable by reference to further mental states. Although important lessons were learned from behaviorism, the project, as it has been presented, was largely abandoned. Although, as I will explain in section 2.3, important aspects of behaviorist theories of mind were later incorporated into functionalist theories of mind.
2.2 Mind-Brain Identity Theory as a Theoretical Precursor to Functionalism: Functionalist theories of mind are also the products of various arguments against type-identity theories of mental and physical states. Psychophysical or ‘mind-brain’ identity theories espouse the view that mental states are physical states. Generally, such theories of identity between some subjective mental state, such as pain, and some physical state, such as neuronal configurations, have been based on the notion of intertheoretic reduction.
Intertheoretic reduction occurs in cases where scientific inquiry discovers that the properties of some thing or event can be explained in terms of, or reduced to, some other thing or event. For example, 'temperature' has been found identical to 'mean kinetic energy of particles' and 'water' has been shown to be identical to 'H2O'. And, even though 'water' is, at least in some respects, conceptually distinct from 'H2O', we take them to be different descriptions of, or referents to, the same thing.
Identity theorists attempt to extend these intertheoretic reductions into the realm of subjective experiences and the physical organizations that are correlated with such experiences. For example, take the identity claim that 'pain' is equivalent to 'physical state x'. Identity theorists will hold that, like the case of 'water' and 'H2O', 'pain' may be conceptually distinct from 'physical state x', but both terms refer to or pick out the same thing. The following is a formulation of mind-brain correlation, which I label 'MBC':
MBC: For each type of mental state M in some system S that occurs at time t, there also exists some physical state of type P in S, such that M occurs in S at t if and only if P occurs in S at t.
But, notice that MBC is a formulation of only correlation between mental and physical states and not a formulation of the identity of mental and physical states. To understand the rationale for moving from correlational theories to identity theories, consider the following remark from J.J.C. Smart, one of the earliest proponents of mind-brain identity theory:
Why do I wish [to identify mental states with physical states]? Mainly because of Occam's razor. . .There does seem to be, so far as science is concerned, nothing in the world but increasingly complex arrangements of physical constituents. All except for one place: in consciousness. . .To say that these [mental states] should be correlated with brain processes does not help, for to say that they are correlated is to say that they are something "over and above". . .So sensations, states of consciousness, do seem to be the one sort of thing left out of the physicalist picture, and for various reasons I just cannot believe that this can be so (1959, p. 142).
A number of objections have been raised, from various theoretical angles, against mind-brain identity theories. However, I will only consider the objection to mind-brain identity theories that is the most powerful and most salient to the current discussion.
Consider the following: if 'pain' is identical to 'neural state x', then it follows that only things that have 'neural state x' can have 'pain'. This relation obtains because if A = B and A is absent from some system, then B must also be absent from the system and vice-versa. The term 'neural state x' picks out a very specific type of physical state. It follows from this that only systems with 'neural state x' can have pain. But this seems false. It is surely inevitable that the same exact neural state does not cause pain in every human.
Further, we can imagine that other species and even aliens of completely different constitutions from us are able to have pains. But, if the identity theory is correct, then this is impossible because only systems with a very specific type of neural state is capable of having pains. This observation has led philosophers of mind to argue that mental states, such as pains, are multiply realizable. In other words, pain can be realized in potentially infinite ways (multiple realization will be discussed further in the following section). This and similar objections, due largely to Lewis (1980), Putnam (1975a, 1975b), and Fodor (1974), set the historical stage for functionalism.
2.3 Functionalist Theories of Mind: The first formulations of functionalism2 were the product of quasi-behavioristic principles and various arguments against type-identity theories of mental and physical states. From behaviorism, early functionalist theories took the concepts of input and output as crucial to understanding the workings of a cognitive system. However, in a radical departure from behaviorism, functionalism defined input and output in terms of a system's internal states. In other words, functionalists were realists about the internal mental states of systems.3 Also, unlike behaviorism, functionalism considered the relation(s) between internal states to be of utmost importance.
The most widely accepted contemporary formulation of functionalism has come to be called causal-theoretical functionalism, which depends on a commonsense (rather than computational) view of mental states (Kim 1996, 104-111; Baker 1995). Causal-theoretical functionalism holds that the concept of a mental state is the concept of a state capable of causing certain kinds of behavior. Some functionalists hold that mental states are definable by a priori conceptual analysis (Baker 1995).
Others hold that functional mental states are definable by empirical analysis and do not require conceptual analysis (Putnam 1975a, 1975b; Harman 1969). For the purposes of my argument, however, I need not rely on any single version of functionalism or version of how functionalist mental states can be defined. Rather, I need only define the conditions that are essential for any functionalist theory of mind. Based on the aforementioned characteristics and theoretical developments, I will present a general formulation of the types of functionalism relevant to my argument which I will call 'Functional Theory of Mind' (hereafter abbreviated as 'FTOM'):
FTOM: A theory of mind x is a functional theory of mind if x holds that (i) an internal state S of some system 
is a mental state in virtue of S's inputs, outputs, and relation(s) to other internal and external states of , (ii) the set of all internal mental states of constitutes a functional description of , and (iii) the functional description of can be realized in different types of substances and in different organizations of such substance(s).
I will briefly attempt to clarify the points in FTOM. In condition (i), inputs can be either perceptual information from the environment external to or inputs from other mental states internal to . Outputs can be behavioral responses, productions of gestures and utterances, or informational inputs to other mental states in . Relations to other internal and external states refers to a state's interaction with other states that are either inside or outside . Condition (ii) is the claim that, given the total set of all the functionally defined states in , we have a complete functional description of the mental properties of . Condition (iii) is a statement of the multiple realizability of functional descriptions.
By reference in (iii) to the possibility of realization in different types of substances and in different organizations of such substance(s), functionalism, as I have generally formulated it, is metaphysically agnostic as to how a given functional description is realized. Hilary Putnam, one of the founders of functionalism, has written of multiple realizability that, "in principle, a machine. . ., a human being, a creature with a silicon chemistry, and a disembodied spirit could all work much the same way when described at the relevant level of abstraction" (1988, p. xii).
In other words, the most important feature of our minds is not the hardware in which it is realized but the functional description which the hardware instantiates. This means that it is possible that a functional description could be realized in any metaphysical system, be it dualistic, physicalistic, or pluralistic, so long as the metaphysical system allows for an implementation of the given functional description.
For example, three functionally identical systems, call them , 
, and 
, need not be realized in the same way. could be a normal adult human composed of biological material, could be an android composed of silicon and other non-organic compounds, and could be a 'disembodied spirit' if this were, in fact, a possible entity with causal relations between mental states. Each of the three entities would have identical psychological behavior and equivalent intelligence. The point to be made here is that functional descriptions of the mental states of systems exist at a higher level of conceptual abstraction than the type of hardware or ‘stuff’ in which such systems are realized.
3. Consciousness: In the last few decades, there has been a surge in philosophical and scientific writings on the topic of consciousness. The need for clarification about exactly what we are referring to when we speak of something being conscious has become apparent to many working on the topic. Among other things, being 'conscious' might be taken to be synonymous with being 'awake', 'aware', 'sentient', 'self-conscious', 'phenomenally conscious', 'introspectively conscious', 'morally conscious', or 'socially conscious'. Within the philosophical literature, the term 'consciousness', which is the state of being conscious, can be found in theories of 'higher-order consciousness', 'discriminatory consciousness', 'responsive consciousness', 'representational consciousness', and more (Tye 1995b, p. 84-87.).
Rather than wading through the myriads of terms and meanings of the words 'consciousness', I will, for the purpose of explicating the meaning of the term as it is relevant to my argument, distinguish between two general types of accounts of consciousness; informational accounts and phenomenal accounts. In making this distinction, I hope to show why informational accounts of consciousness do not constitute the type of consciousness that is philosophically interesting or is the type of consciousness referred to in folk psychological terms.
3.1 Informational Accounts of Consciousness: Informational accounts of consciousness are those that are (i) considered from the third-person perspective, (ii) defined objectively, (iii) involved with information-processing. Such cognitive processing descriptions of consciousness have been proposed in many areas of research. The majority of cognitive psychological and neurophysiological theories of consciousness are informational accounts of consciousness because they satisfy (i)-(iii). For example, Crick and Koch have suggested that 40hz oscillations in the spiking frequencies of neurons bind relevant brain areas and function to ". . .present the result of various underlying computations. . ." and ". . .join together some of the existing information into a coherent percept" (1997, p. 288).
Also, a number of philosophers have attempted to clarify between types of consciousness, usually by contrasting phenomenal types of consciousness with informational types of consciousness. Ned Block distinguishes between phenomenal and access consciousness, where the latter is an informational account. A state or representation is access conscious, according to Block, ". . .if it is poised for free use in reasoning and for direct 'rational' control of action and speech" (1997, p. 382).
Georges Rey has distinguished between strong and weak consciousness, the latter of which is of the informational type. Rey writes that weak consciousness involves, ". . .merely wakefulness, attention, or reportability and is of obvious utility to psychology" (1997, p. 474). Various other philosophers have proposed and endorsed higher-order theories of consciousness, representational theories of consciousness, and monitoring theories of consciousness- none of which necessarily require descriptions of phenomenal consciousness and generally fit under the informational accounts of consciousness category.4
There are, however, two salient problems with informational accounts of consciousness with respect to their philosophical importance. The first problem is that none of the informational theories address the so-called "hard problem" (Chalmers 1996) of why certain physical states are related to phenomenal experiences of one kind or another. A second difficulty with many informational theories of consciousness is that they generally assume that they will find the most salient physical correlate of consciousness at the level of neuronal organization.
Others, such as Roger Penrose, have theorized that consciousness will only be understood at the level of quantum organization (1994). But, what criteria do we have on which to judge which conceptual level of physical organization is more apt to yield an understanding of how phenomenal consciousness arises?
Colin McGinn has said of these problems, "Somehow, we feel, the water of the physical brain is turned into the wine of consciousness, but we draw a total blank on the nature of this conversion. Neural transmissions just seem like the wrong kind of materials with which to bring consciousness into the world. . ." (1989, p. 349). I think that McGinn would be forced to say the same of all attempts to view phenomenal consciousness as being produced by any given level of physical or non-physical organization.
Although informational accounts of consciousness may be important for pragmatic scientific endeavors, such types of consciousness are not philosophically problematic. In the following section, I will argue that phenomenal consciousness is the type of consciousness that is the meaning of the term 'consciousness' in folk psychological terminology and that phenomenal consciousness is the relevant type of consciousness with respect to my argument.
3.2 Phenomenal Accounts of Consciousness: Phenomenal accounts of consciousness, in comparison to informational accounts of consciousness, are much more resistant to definition. Consider the following lines by John Searle:
By consciousness I simply mean those subjective states of awareness or sentience that begin when one wakes in the morning and continue throughout the period that one is awake until one falls into a dreamless sleep, into a coma, or dies or is otherwise, as they say, unconscious (Searle 1990, p. 632).
This resistance to definition is indicative of a problem in attempting to capture the essence of phenomenal consciousness. However, a number of terms and phrases have been used to try to refer the nature of 'what-it-is-like'5 to experience colors, sounds, tastes, and pains. One word that is used to refer to properties of something's phenomenal consciousness is 'qualia'. Qualia is the plural form of the word 'quale', where quale is used to describe properties of experiences, such as "his red quale", "her banana quale", and "its nauseous quale".
Some thing x's 'qualia' then, refers to the total set of various quales of x's experience. Sometimes this total set is referred to as x's 'qualitative experience', 'subjective experience', 'subjective feel', and 'raw feel'- phrases which have all been used to refer to the same thing or set of things that the terms 'qualia' and 'what-it-is-like' attempt to refer to. To see how many things such terms attempt to capture, consider the following list-like description of phenomenally conscious states by Michael Tye:
Which states are phenomenally conscious?. . . Perceptual experiences, for example, experiences of the sort involved in seeing green, hearing loud trumpets, tasting licorice, smelling the sea air. . . Bodily sensations, for example, feeling a twinge of pain, feeling an itch, feeling hungry. . . Felt reactions or passions or emotions, for example, feeling delight, lust, fear, love, grief. . . Felt moods, for example, feeling happy, depressed, calm, bored, tense, miserable. . . (1995a, p. 4).
Through such examples and attempts at definition, I hope to make it apparent that phenomenal consciousness is the type of consciousness that has posed fundamental problems for theories of mind and theories of how the mind is related to reality. Although the prefix 'phenomenal' is not included in all uses of the word 'consciousness', it is apparent that phenomenal consciousness is the type of consciousness that has prompted Thomas Nagel to write that, "Consciousness is what makes the mind-body problem really intractable" (1974, p. 165).
Jerry Fodor has remarked that of the, ". . .three great metaphysical puzzles about the mind. . .", the first one is, "How could anything material have conscious states?" (1991, in reply to Devitt, p. 285). Phenomenal consciousness is also the type of consciousness that prompted the positing of an "explanatory gap" between phenomenal and physical states (Levine 1983, p. 354-361).
In what follows, I will use exclusively the term phenomenal consciousness (hereafter abbreviated 'PC') to mean that which all of the above terms are attempting to refer to. Something's PC, then, is the total set of its phenomenal experiences, of its qualitative states, etc. It should be mentioned that the term 'qualia', which I take to be synonymous with PC, will be used in place of PC by some authors in what follows.
3. 3 Phenomenal Consciousness Inessentialism: In the previous sections on consciousness, I have made the case that PC is the type of consciousness that is associated with the nature of experience and is the philosophically problematic form of consciousness. Now I will present a number of fundamentally parallel views that take PC to be an inessential feature of functionally described cognitive systems.6 Owen Flanagan writes of this view:
It is conceivable that. . . [there could be]. . . creatures as efficient and intelligent as we are, even more efficient and intelligent, without those creatures being subjects of experience. Conscious inessentialism is the view that for any intelligent activity i performed in any cognitive domain d, even if we do i consciously, i can in principle be done nonconsciously (1992, p. 129).
Flanagan does not mention 'phenomenal' in his definition of 'conscious inessentialism'. However, he does refer to "creatures being subjects of experience". As in other cases, the prefix of 'phenomenal' is left out, but given context, it is certainly implied. Similarly,
T.C. Moody has remarked:
Given any functional description of cognition, as detailed and complete as one can imagine, it will still make sense to suppose that there could be insentient beings that exemplify that description. That is, it is possible that there could be a behaviorally indiscernible but insentient simulacrum of a human cognizer. . . (1994, p. 196).
Others, such as Ned Block, have written of the view that PC is inessential in terms of an objection to functionalism:
The Absent Qualia Objection proceeds. . . with an argument that it is possible that a mental state of a person x be functionally identical to a state y, even though x's state has qualitative character while y's state lacks qualitative character altogehter (1980, p. 258).
Block uses the term 'Absent Qualia' instead of 'absent PC'. However, as I mentioned earlier, 'qualia' and 'PC' are, for the purposes of my argument, interchangeable terms. Also, for some state to "have qualitative character" is for that state to have some feature such that it has, produces, or is used in part for the production of PC. Each of the aforementioned passages are descriptions of the doctrine of phenomenal consciousness inessentialism (hereafter abbreviated as 'PCI'), which I define as follows:
PCI: If some system has a complete functional description F and if some system has a complete functional description F, such that F = F, then it is possible that possess PC and does not possess PC.
Remember from FTOM that mental states are defined in terms of their relations to inputs, outputs, and other internal and external states. Therefore, for the identity relation F = F to hold, the total set of all mental states specified by F must have the same causal relations to inputs, outputs and other internal and external states as the total set of mental states specified by F.
Functionally equivalent systems7 possess psychologies that are, at the functional level, equivalent within a functionalist theory of mind. Functionally identical systems are, as psychologically identical systems, also identical in terms of their intelligent behavior8.
In other words, two functionally identical systems should be capable of having the same degree of understanding, reasoning, and complexity of intentional states towards themselves and the world. However, as previously mentioned in the discussion of multiple realizability (section 2.3), functional identity does not entail identical physical constitution; although it certainly does not rule out that two functionally identical systems could not also be physically identical.
With these considerations in mind, let us return to further clarification of PCI and consider the case, for example, in which system is a normal adult human and system is an android and in which is functionally identical to . According to PCI, the two systems would be psychologically equivalent in that each would be as intelligent and expressive of this intelligence as the other. But, given the truth of PCI, it would be possible for and to also be completely different with respect to their PC.
The human could experience a rich world of colors, sounds, and feelings- while the android could exist in a phenomenally bare world, devoid of experience. However, it is important to note that, given that and both have the same psychology, their answers to questions about their experience of the world (or lack of experience) will be the same.
If is asked about its 'experience' of seeing a rainbow, or the 'feel' of its injury, it would respond with the same accuracy and descriptive clarity that would respond with. In what follows, I will use the term 'zombie'9 to refer to a system, like , that does not possess PC but is functionally identical to a normal adult human being. A zombie, then, is a possibly existent being- given the truth of PCI. For clarity, I will define a zombie as follows:
(def. zombie) Some being x is a zombie if and only if x is (i) functionally identical to a normal adult human and (ii) x does not possess PC.
The conditions for being a zombie are, I think, unobjectionably possible if we consider each necessary but insufficient condition in isolation from the other. Condition (i), independently of (ii), is possible because it is of the form: could there be an x, such that x satisfies the following, "x is functionally identical to a human"?
This is trivially true because other normal adult humans could satisfy the role of x as well as anything else that could be realized with the functional description of a normal adult human. Sufficient zombie condition (ii), independently of (i), is possible because it is of the form: could there be an x, such that x satisfies the following, "x does not possess PC"? I take it to be unobjectionable that we think many things could be in x's position- rocks, rivers, etc.
It should be noted that an influential and significant portion of philosophers working in philosophy of mind take zombies to be possibly existent beings and, therefore, accept the truth of PCI (Kirk 1974; Nagel 1974; Block 1980b; Doore 1981; Jackson 1982; Conee 1985; Flanagan 1992; Moody 1994; Flanagan and Polger 1995).10 My arguments will be most relevant to these philosophers. Now, having formulated PCI and having described the relevant terms and ideas, I now move on to my first argument.
4. The Argument for the Possibility of Humanized Zombies: In this section, I will formulate and defend my argument for humanized zombies. As previously mentioned, zombies are beings that do not possess PC and are functionally equivalent to humans or other creatures that we assume do possess PC. Through my argument, I hope to show that a consequence of the truth of PCI is that zombies, given their functional and therefore psychological identity to creatures that we take to possess PC, will necessarily believe that they possess PC. |
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Because these zombies believe that they are humans, I will refer to them as humanized zombies. Note that my argument will require that I show only that it is possible that zombies exist- not necessarily that they actually do exist. Given this modal amendment, consider the following argument for the possibility of humanized zombies (hereafter abbreviated as 'PHZ'), which I formulate as follows:
(1) it is possible that zombies exist
(2) humans believe that they possess PC
(3) beliefs are functionally definable mental states
(4) therefore, it is possible that zombies exist and, if zombies exist, then zombies believe that they possess PC
I take premise (1) of PHZ to be exemplary of a zombie, as previously described, and to be true if PCI is true. Premise (2) of PHZ will require some analysis against potential objections. Premise (3) will also require justification. The conclusion of PHZ (4), which follows from the truth of the premises (1-3), presents what I call a humanized zombie; a zombie that believes that it possesses PC from its first-person perspective even though it does not actually possess PC. Before drawing any conclusions from PHZ, I must first show that each of the premises (1-3), are true. In the remainder of this section, then, I will defend PHZ against various criticisms that could potentially be put forth against it.
4.1 The Objection to PHZ from Inconceivability: This is an objection to the first premise of PHZ. Though there are a number of ways in which this objection can be construed against PHZ, I think that the most salient construal of this objection is:
Premise (1) of PHZ describes an entity that is inconceivable. Inconceivability implies impossibility. Therefore, zombies are not possibly existent beings.
The first important point in examining this objection is to notice that the word 'conceivable' can be construed in an objective or a subjective sense. Objective conceiving, with respect to zombies, is conceiving that there exists some being such that it satisfies its definition of not possessing PC and being functionally equivalent to a normal adult human. Subjective conceiving, with respect to zombies, is conceiving of a zombie in the objective sense and attempting to conceive of what it would be like to be the zombie.11
Now, one could make the case that it is possible to conceive of nothing, which is what it would be like to be a zombie. Being able to conceive of nothing would satisfy the claim that zombies do not possess PC. But, could one conceive of nothing and at the same time conceive of how it would be possible to taste foods, speak about one's favorite colors, appreciate classical music, and laugh at good jokes?
I think not. On the one hand we must conceive of a total lack of experiential content together with discriminatory perceptual abilities. One would have to conceive of both nothing and something at the same time in order to subjectively conceive of being a zombie
Based on this, I do not want to object to the claim that zombies, as they are defined by PHZ, are subjectively inconceivable. But, many things that we know exist are inconceivable in this sense. Bats, worms, and rocks exist, yet they are inconceivable if, by 'conceivability', we mean 'trying to put ourselves in the subjective position of such entities'. Obviously, then, subjective inconceivability does not entail the impossibility of something existing. The question, then, is whether or not objective inconceivability is attained in the case of zombies as defined by PHZ and whether or not objective inconceivability implies impossibility.
Objective inconceivability is reserved for things or events that are inconceivable because of some property that makes them contradictory. For example, a square circle is something that has the property of being four-sided and has the property of being the set of all points equidistant from its center. This is a simple case of something being A and ~A at the same time, and hence, of such a thing being impossible. An objection to PHZ from objective inconceivability would look like the following:
Premise (1) of PHZ describes an entity that is objectively inconceivable. Objective inconceivability implies impossibility. Therefore, zombies are not possibly existent beings.
In examining this objection, it is at least fairly obvious that humans can hold beliefs which may or may not correspond to the way things actually are. For example, some person K may believe that she has ten dollars in her pocket without it actually being the case that she has ten dollars in her pocket. We do not think, generally, that beliefs need latch on to any actual features of the world.
But, there at least seems to be a difference between beliefs about states of affairs in the 'world', and phenomenally experienced states. Consider whether or not K could have the belief that she is experiencing red without her actually experiencing red. Whatever it is that K believes is 'an experience of red', for K, is an experience of red. There is, at least on the surface of it, no difference between the appearance and reality of the belief.
However, the possibility that defeats the objection from objective inconceivability is that K's experience of red could be empty because, in dealing with what phenomenal experiences correspond to, we have no way to check them against something for validity.
If it were the case, for example, that K was missing PC, but she believed that she was, at some time, having an experience of red, to what would she compare this experience (or lack of experience) in order to verify that it was or was not, in fact, an experience of red? In other words, it can only be subjectively inconceivable that some being without PC could report on and discriminate between what we take to require phenomenal experience. It is not, therefore, objectively inconceivable and the objection from inconceivability fails.
4.2 The Objection to PHZ from Causal Knowledge of Qualia: The objection from the causal knowledge of qualia12 is another objection to premise (1) of PHZ- that zombies possibly exist. A number of philosophers have defended the view that 'absent qualia' or lack of PC in one system, given the functional identity of the two systems in question, is logically impossible (Shoemaker 1975, 1981; Davis 1982; Elugardo 1983). In other words, this would be a denial of PCI as previously asserted by Flanagan, Moody, Block and others in section 3.3.
Remember that functional identity between two mental states holds if and only if they each have the same causal relations to inputs, outputs, and other mental states. Most objections to functional descriptions as complete descriptions of systems include the missing phenomenal experience or 'absent qualia' objection (all of which are equivalent to the 'missing PC' objection).
Most notably, Sydney Shoemaker has defended the view that PCI is impossible in one of two functionally identical systems. Shoemaker argues that 'absent qualia' or PCI is impossible because we have knowledge of our PC, and knowledge must be gained from a causally efficacious source. Therefore, our PC must be included in a complete functional description, because any description that leaves out PC is not complete functional description of humans. Summarizing Shoemaker's view:
If absent qualia are possible, then the presence or absence of the qualitative character of pain would make no difference to its causal consequences; and so, according to a causal theory of knowledge, we could have no knowledge of the qualitative character of pain; but given that we do have knowledge of the qualitative character of pain, absent qualia are not possible (Shoemaker 1975, p. 291-315).
However, against Shoemaker, a number of philosophers have maintained that absent PC or absent qualia are possible (Kirk 1974; Nagel 1974; Doore 1981; Jackson 1982; Conee 1985; Flanagan 1992; Moody 1994; Flanagan and Polger 1995). Ned Block, as one of the most ardent critics of Shoemaker's arguments, has upheld the possibility of missing PC in functionally characterized systems (1980a, 1980b). In other words, Block argues that zombies are possible and that PCI is true if we take functional descriptions to be complete descriptions of the mind.13 In refuting Shoemaker's view, Block does not argue that Shoemaker's causal theory of knowledge is wrong or that we do not have knowledge of the phenomenal (or qualitative) character of our pains. Rather, he disagrees with Shoemaker's first premise. Block writes:
If absent qualia are possible, there could be a state functionally identical to pain that lacks qualitative character (call it "ersatz pain"). But ersatz14 pain could be possible even though the qualitative character of genuine pain is crucial to producing the consequences that are produced in another way by ersatz pain (Block 1980b, p. 259).
Block thinks that Shoemaker's first premise hinges on an ambiguity that clearly undermines Shoemaker's argument. In order to highlight this problem in Shoemaker’s argument, imagine that some system has some functional state S that has some feature F, such that F makes no causal difference to S's causal role. Therefore, on a causal theory of knowledge, could not know of F because it makes no causal difference to the functional state.
However, this does not disallow the possibility of the following situation: Assume that system has some functional state S1 that is functionally identical to a functional state S, such that S1 lacks F, but has the same causal role as state S, which has F (Block 1980b, p. 264). In order to clarify precisely what this means, I will use a rather simple example abstracted from Block (1980b, p. 262). Assume that state S is a spring-loaded, old-fashioned mouse trap on which you put a piece of cheese, and that S1 is a flat, weighted mouse trap pad of approximately the same size as the mousetrap with an extremely sticky adhesive that smells like cheese.
Both of these devices have the same functional role in terms of their inputs, outputs, and functionally relevant relations to the environment. In the first trap, the mouse (the input) will become trapped (the output) by the spring-loaded mechanism. In the second trap, the mouse (the input) will become trapped (the output) by the sticky surface of the weighted pad. However, we can say that S, the spring-loaded mouse trap, has causal feature F, where F could be the causal powers of the spring. And, we can say that S1, the sticky pad mouse trap, does not have causal feature F, because it lacks the spring mechanism.
Analogously, according to Block, we can assume that certain functionally identical mental states have causal features that are not shared just because they are functionally equivalent. In other words, two states may be functionally identical, but one state may have different causal powers than the other. This objection successfully allows for possibility of entities that are functionally equivalent to humans but do not possess PC, because PC can be the 'spring' that is missing in certain functionally identical mental states which do have the same functionally relevant causal powers.
If Block’s reply is sound, then PC does not play an essential role in any functional state. In other words, some state S that has a feature F, where F causes PC, could be functionally identical to some state S1, which does not have feature F, but where it has feature F1 that does not cause PC. However, it could be argued that, contrary to Block's analysis of functional roles, PC does play an essential role in certain functional states.15 This would be equivalent to the following:
For any mental state S that has a causal feature F, where F produces or aids in the production of PC, S can not be functionally equivalent to some mental state S1 that does not have a causal feature F1, where F1 produces or aids in the production of PC.
What is the justification for the above claim? S is a state that has some feature F that causes or aids in causing phenomenal consciousness. There is certainly nothing in the notion of causation that prevents the situation in which there are two functionally identical states, where one causes PC and the other does not.
Recall the aforementioned mousetrap example, and think of PC as being caused by the non-functionally relevant causal feature (the spring) in the first mouse trap. But, if the argument for PC as an essential feature of the causal role of PC producing mental states is correct, then PC must have some special characteristic that sets it apart from other causal features of mental states. What is this special feature?
There are two ways in which the claim that PC is causally unique can be rejected. First, if PC is causally relevant, then there is no a priori reason, based on the concept of causality, that would separate PC from anything else that is causally efficacious. And, there is no a posteriori justification for accepting that PC has some special causal property such that it is causally distinct from other causally efficacious states. Secondly, if PC is not causally relevant, then PCI is vindicated and PC is a feature of mental states that is entirely non-influential of the causal functional roles of certain mental states.
Therefore, I do not see any reason to think that PC is an essential feature of certain the functional causal roles of certain mental states. One possible objection to this line of reasoning is that I have not disproven that PC is an essential part of certain mental states and that such states can not be functionally identical to non-PC producing mental states. However, I do not take it to be necessary to disprove such claims because no sufficient justification for assuming such claims about the causal nature of PC-producing, functionally defined, mental states has been provided in the first place. Therefore,I find that Block’s argument against Shoemaker does show that there could be zombies or, in other words, beings that exemplify the truth of PCI.
4.3 The Objection to PHZ that Humans do not Believe they Possess PC: This is an objection to premise (2) of PHZ. The objection must take it to be the case that humans do not believe that they possess PC, or in other words, humans do not believe that they have phenomenal experiences of various kinds. Some may reject premise (2) of PHZ on the grounds that to have a belief requires the realization that the referent of the belief may not actually obtain or may be false. This would be to take the restrictive position towards beliefs endorsed by Donald Davidson, who writes:
Someone cannot have a belief unless he understands the possibility of being mistaken, and this requires grasping the contrast between truth and error- true belief and false belief (1984, p. 170).
Therefore, according to the argument, because humans can not entertain the thought that their belief about, for example, seeing red, could be false, they also can not, therefore, have a belief that they are seeing red. There are two ways in which to respond to this problem.
Firstly, if this objection to premise (2) of PHZ is correct, then humans also can not know they are seeing red. This follows, assuming that we want to maintain our understanding of knowledge as warranted belief. If we allow that this definition of knowledge is one that we should keep, then it would be the case that humans neither believe nor know that they are seeing red when they report or consider their experience of red. If it were the case that humans could neither believe nor know they were experiencing something, then there would be no basis on which anyone could assert that they are having some particular phenomenal experience.
Secondly, even if we allow that, in order to have a belief, one must be capable of realizing that such a belief may be mistaken, the objection can still be escaped because we can doubt whether or not our introspective evidence is certain with respect to beliefs about PC. How is this possible? Consider the following passage by Daniel Dennett:
Even if it is intuitively plausible that you cannot be mistaken about how it is with you right now, it is not at all intuitively plausible that you cannot be mistaken about his it was with you back then. . . Perhaps your experience was actually one way, but you now misremember it as having been another way. . . The logical possibility of misremembering is opened up no matter how short the time interval between actual experience and subsequent recall. . . (1991, p. 318).
A similar line has been taken by D.M. Armstrong, in which he constructs a thought experiment where some person at time t believes that he experienced pain two seconds prior to t. However, Armstrong imagines that a super-neurosurgeon has changed his memory such that, although he believes that he experienced pain two seconds before time t, he did not actually experience pain two seconds before t (1963, p. 432-433). Therefore, Armstrong concludes that, ". . . it is a mistake to say that introspective reports are indubitable or have a logically special authority. . . " (1963, p. 432). These examples allow for the possibility that introspective beliefs are false. Therefore, even if one takes the Davidsonian line concerning the nature of beliefs, the objection fails.
"The Monad" painting by Anthony Peter Iannini, 2006
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4.4 The Objection that Beliefs can not be Functionally Defined: This is an objection to premise (3) of PHZ. If it is true that beliefs cannot be functionally defined, then it is true that PHZ fails and that functionalism may fail, because functionalism is then incapable of capturing the content propositional attitudes.16 However, functionalists do take functionalism to be able to incorporate the content of propositional attitudes as capturable within a functional description. The necessary space required for examining such criticisms of functionalism's ability to capture propostitional attitudes is not within the scope of this paper.17
However, it is clear that a functional definition of intentional states (beliefs that x, desires that x, etc.) which includes the semantic content of such states is plausible on a number of accounts (Hartry 1977; McGinn 1982; Block 1986; Fodor, 1987; Silverberg 1992). And, even if there are problems with the functional definability of beliefs, my argument is most relevant to those who already take beliefs to be functionally definable mental states.
Any philosopher who asserts the truth of PCI or allows for the possibility of zombies must take intentional states to be functionally definable. Also notice that, although there may be PC accompanying or being triggered by propositional attitudes, there is no necessary connection between a propositional attitude and some phenomenal experience.18 My goal is to show that phenomenal accounts of mental states should not pose a problem for functionalist, or objective, accounts of the mind. Therefore, this objection is largely irrelevant to my project. |
5. The Argument for Zombified Humans: In this section, I shall show how the aforementioned arguments that validate PHZ can also be used to validate an argument for zombified humans. Zombified humans are humans that, like zombies, believe they possess PC but do not actually possess PC. In order to present this argument, it will be necessary to recall Shoemaker's argument against the possibility of zombies in section 4.2, which is formally outlined, for convenience, as follows:
(i) if absent qualia are possible, then the presence or absence of the qualitative character of pain would have no causal powers
(ii) if F is a feature of a mental state S, and F is entirely independent of the causal powers of S, then F is not knowable.
(iii) the qualitative character of pain is knowable
(iv) therefore, absent qualia are not possible
Recall that Block, in his successful argument against Shoemaker (in section 4.2), does not contest premises (ii) and (iii). In other words, Block has ". . . no quarrel with any reasonable version of a causal theory knowledge. . . " nor does Block ". . . wish to doubt Shoemaker's assumption that we have knowledge of the qualitative character of our pain" (1980, p. 259). Instead, Block disagrees with Shoemaker’s first premise (i), because it does allows the possibility of some system that has some functional state S1 that is functionally identical to a functional state S, such that S1 lacks F, but has the same causal role as state S (Block, 1980, p. 264).
In other words, two states may be functionally identical, but one state may have different causal powers than the other, where the different causal powers do not affect the functional role of the state. Again consider that Block, in his argument against Shoemaker, accepts premises (ii) and (iii), and in doing so, assumes that:
(I) humans possess PC
(II) humans have knowledge of their PC
(III) a causal theory of knowledge accounts for the assumption that (II)
The crucial point to be made here is that Block's objection to Shoemaker consists in demonstrating that beings, functionally identical to humans, can exist without PC independently of whether or not humans actually possess PC. Block's assumption (I) need not be true for his argument for the possibility of absent qualia to be true. Rather, Block's assumption (I) must be true for his overall 'absent qualia' objection against functionalism to be successful.
In what follows, I shall argue that Block's argument allows for a serious skeptical challenge to (I) a challenge adequately strong enough to undermine the assumption that humans actually do possess PC. I will, for convenience, again display the argument for the possibility of humanized zombies or PHZ:
(1) it is possible that zombies exist
(2) humans believe that they possess PC
(3) beliefs are functionally definable mental states
(4) therefore, it is possible that zombies exist and, if zombies exist, then zombies believe that they possess PC
Nowhere in PHZ (1-4 above) is there a mention of humans actually possessing PC. Rather, there is only premise (2), which states that humans believe that they possess PC. This means that PHZ does not need to assume that humans actually are phenomenally conscious for PHZ to be true. I will draw out this claim in my argument for zombified humans (hereafter abbreviated as 'AZH'):
(a) it is possible that zombies exist
(b) zombies believe that they possess PC
(c) therefore, that some being x believes that it possess PC does not entail that x actually possess PC
Premise (a) of AZH is identical to premise (1) of PHZ, and premise (b) of AZH is identical to the conclusion (4) of PHZ, both of which have been vindicated in section 4. The move from (a) and (b) to the conclusion, (c) follows from the possible existence of humanized zombies. Consider the following premise and its corresponding conclusion that I will add to AZH:
(d) actual humans believe they possess PC
(e) therefore, it is possible that actual humans do not possess PC
Premise (d) of AZH is identical to premise (2) of PHZ (which has already been vindicated in section 4), and the conclusion (e) of AZH follows from the combination of (c) and (d) of AZH. In order to clarify how (e) was reached, recall that Block's argument supports the truth of PCI or the possibility of humanized zombies in order to eventually show that functionalism is not a complete model of the mind because of Block's assumption (I) that humans possess PC. But, if PCI is true or humanized zombies are possible, then humans may be humanized zombies. For clarity, I shall summarize the structure of Block's argument and hereafter refer to this summarization as 'BA1':
BA1: All humans, which are beings of functional type , have PC. A FTOM does not necessarily incorporate PC into its description of beings of functional type . Therefore, a FTOM allows for the possibility of beings of functional type that do not actually have PC. Therefore, a FTOM is inadequate as a description of beings of functional type that have PC.
Next, I present a similar summary of Block's argument that is slightly augmented to reflect the consequences of AHZ. The following is my revision of BA1, which I will hereafter refer to as 'BA2':
BA2: All humans, which are beings of functional type , believe that they have PC and actually do have PC. A FTOM does not necessarily incorporate PC into its description of beings of functional type . Therefore, a FTOM allows for the possibility of beings of functional type that believe that they have PC but that do not actually have PC. Therefore, a FTOM is false as a description of beings of functional type that have PC.
The problematic line in BA2 that is missing in BA1 is that, "Therefore, a FTOM allows for the possibility of beings of functional type that believe that they possess PC but that do not possess PC". If it is true that humanized zombies possibly exist, then this possibility undermines Block’s first assumption that "All humans. . .believe that they have PC and actually do have PC". We know, from the humanized zombie allowed for by FTOM, that belief in one's possession of PC does not entail one's actual possession of PC.
Therefore, unless a reason can be presented for how humans know that they have PC, above and beyond believing that they have PC, then there seems to be no warrant for assuming that humans actually do or do not have PC in the first place. In other words, if AHZ is sound, then, given the entailed possible existence of humanized zombies, we are left with the conclusion (e) of AZH: it is possible that actual humans do not possess PC.
There are a number of ways in which (e), the conclusion of AZH, can be met. Firstly, (i) one could take (e) to be true but also argue that (e) is not grounds for skepticism because it is possible to objectively verify the existence of PC in actual humans. Secondly, (ii) one could take (e) to be true and take (e) to be grounds for skepticism about only the possibility of PCI or absent qualia in other actual humans because it is possible to subjectively verify the existence of PC in oneself.
Thirdly, (iii) one could take (e) to be true and take (e) to be grounds for skepticism about both the possibility of PCI or absent qualia in other actual humans and in ourselves, because we can neither objectively nor subjectively verify the existence of PC in others or in ourselves. In what follows, I will examine the possibilities of objective and subjective verification of the existence of PC as potential remedies to (e), the conclusion of AZH.
5.1 The Impossibility of Verifying the Existence of PC in Humans, Given AZH: Can humans somehow objectively verify or test for the existence of PC in themselves? I will assume, for the purposes of this discussion, that humans are generally functionally and physically identical, given certain constraints on normality.19 Given that it is possible that humans do not possess PC, it follows that only one of three possibilities could be true of the actual world. It is either the case that (AH) all humans possess PC, (SH) some humans possess PC, or (NH) no humans possess PC.
In what follows, I shall argue that the only possibility that can even be potentially ruled out from an objective standpoint is the possibility that (SH). A case could be made that (SH) can be ruled out on objective grounds that there is strong correlational evidence to show that all humans display the same introspective reports concerning their experiences given highly similar physiological states.
But, even if the possibility that (SH) is shown to be implausible, this still leaves us with the possibility that (AH) and the possibility that (NH). And, in principle, there is no way to distinguish between the case in which (AH) is true of the actual world and the case in which (NH) is true of the actual world. If the possibility of humanized zombies is accepted, then humans certainly could have evolved as Owen Flanagan describes in the following passage:
It is conceivable that evolutionary processes could have worked to build creatures as efficient and intelligent as we are, even more efficient and intelligent, without those creatures being subjects of experience (1992, p. 129).
And, if humans in the actual world did evolve as Flanagan describes it being possible to evolve, how would humans come to know this? Consider the following lines about a possible 'zombie-earth' by Güven Güzeldere:
Of course, the inhabitants of the 'zombie-earth' may be construed as not really having dreams or experiences, but just only mistakenly believing that they are. . . Nonetheless, there would not be a way for us, or even for them, to find this out. . . for every human mental-activity on earth, there is a corresponding zombie mental-activityZ, and, there are, in principle, no differences between them to be discovered or to be discoveredZ (1994, p. 331).
If humans were actually zombified humans, there would be no way for anyone to know this. Some philosophers who accept the truth of PCI and the possibility of humanized zombies, fail to recognize this fundamental problem in objectively verifying the difference between zombies and non-zombies.
For example, T.C. Moody writes that ". . . at the level of culture there are necessary behavioral differences between zombies and non-zombies, because those differences are the result of the differences in the conceptual vocabularies available to each culture. At the level of culture, conscious inessentialism is false" (1994, p. 199). In the same manner, Flanagan and Polger argue that, ". . . zombie inhabitants. . . would be distinguishable from us, because, lacking conscious lives, the zombies would never indeed, could never, develop the mentalistic concepts and vocabulary that we have" (1994, p. 315).
However, Moody, Flanagan, and Polger have overlooked a few crucial details. As Daniel Dennett points out, it follows trivially from the definition of a zombie that, ". . . zombies are 'behavioral' twins of conscious beings; if it is likely that we conscious folks would develop mentalistic vocabulary, then it must be exactly as likely that zombies do" (1994, p. 322). In other words, searching for a verifiable behavioral difference in zombies forgets that zombies, which are functional isomorphs of humans, are also necessarily intelligent behavioral isomorphs of humans.
And, according to PHZ, zombies are really humanized zombies that believe that they have PC. Perhaps we could find humanoids that never developed the concept of PC or anything similar to the concept of PC in their language, culture, or philosophy. However, this finding does not entail that such humanoids do not possess PC. This would be analogous to asserting that medieval Europeans never had antibodies to viri because they did not have the concept of antibodies.
5.2 The Impossibility of Verifying the Existence of PC in Yourself, Given AZH: You might argue that you can simply introspect and subjectively verify whether or not you possess PC. However, you forgot that your beliefs in your possession of PC do no necessarily entail your actual possession of PC. You may continue to insist that you, and humans in general, both believe that you possess PC and that you actually possess PC. But how can you verify, even from your own first-person perspective, whether or not your beliefs about your possession of PC correspond to your actual possession of PC?
Block's objection to Shoemaker (in section 4.2) allows for you to have some functional state S that accounts for the causal feature F of state S that causes you to believe that you actually have phenomenal consciousness. This could be the case without you actually having some functionally definable state S1 that has the same functional role as S, but has a causal feature F1 that is not identical to causal feature F, where F1 actually causes PC but where F does not cause PC.
Therefore, it is possible that you have certain mental states that cause you to believe that you have PC when you actually do not have PC. Consider the corrigibility of phenomenal beliefs suggested in section 4.3. A number of philosophers have maintained that beliefs about one's phenomenal experiences are, for a number of reasons, not incorrigible (Chandler 1970; Lehrer 1974, p. 80-101; Tomberlin 1975; Ellis 1976; Doppelt 1978, 1979).
Also, the following situation is saliently possible. Suppose that all humans do actually possess PC (remember that this would be an objectively unverifiable situation). One night, while you are sleeping, a neuroscientist drugs you and takes you to his lab. While you are asleep, the scientist removes the physical (neural) instantiation of your functional state that causes you to have PC. Then, he replaces your missing functional state with another functionally identical state that lacks the causal powers to produce PC but does still cause you to believe that you possess PC.
Notice that maintaining functional identity entails maintaining your beliefs about your PC. The next morning upon awakening, you notice nothing different. As you 'look' out your window at the warm orange sun rising, 'taste' your coffee, or 'hear' the birds chirping, you still believe that you are having such phenomenal experiences even though you are no longer, by definition, actually having such phenomenal experiences. In this situation, you are the ignorant exemplar of inverse solipsism, the position in which you are the only human without PC and neither you nor the evil neurosurgeon nor anyone else can know this is this case.
6. Conclusion: My original thesis was that (i) arguments, which successfully show that functionalist mental descriptions allow for the possibility of absent phenomenal consciousness, bring up serious skeptical issues concerning third-person and first-person attributions of phenomenal consciousness and therefore, (ii) such arguments against functionalism do not imply the falsity of functionalism. The preceding sections have been dedicated to part (i) of my thesis. Now, I explain why (ii) follows from the truth of (i). Consider again the conclusion of AZH:
(e) it is possible that actual humans do not possess PC
The conclusion, (e), of AZH was reached in the context in which functionalism was assumed and in which a case was made for functionalism's entailment of PCI. Therefore, if my arguments have been sound, this conclusion (e) can be rewritten as the following conditional that respects the context of the argument that assumed functionalism:
(e1) If functionalism is true, then it is possible that humans do not possess PC
Also, I have made a case for the impossibility of verifying the existence of PC is others and in one's own case if functionalism (which entails PCI) is true. Therefore, (e1) can be rewritten as:
(e2) if functionalism is true, then it would be impossible to verify the existence of PC in others and in one's own case
In light of (e2), I will restate the first part of my original thesis that "(i) arguments, which successfully show that functionalist mental descriptions allow for the possibility of absent phenomenal consciousness, bring up serious skeptical issues concerning third-person and first-person attributions of phenomenal consciousness...". (e2) is the conclusion that supports (i), the first part of my thesis. The second part of my original thesis begins where the first part left off and continues "[part (i)]...and therefore, (ii) such arguments against functionalism do not imply the falsity of functionalism".
In other words, (ii) is the claim that arguments, which lead to something like (e2), do not imply the falsity of functionalism because such arguments, like (e2), bring up serious skeptical issues concerning third-person and first-person attributions of PC. In order to clarify this point, I will construct an argument against the second part of my thesis (ii), and, in doing so, show why such objections are fundamentally misguided. The following is an argument of someone who takes (e2) to be reason why functionalism is false:
(1) if functionalism is true, then it would be impossible to verify the existence of PC in others and in one's own case
(2) I can verify the existence of PC in my own case
(3) therefore, functionalism is false
Premise (1) is just a restatement of (e2). However, premise (2) can not be true if functionalism is true. That one relies on evidence for one's PC does not, by itself, rule out the truth of functionalism because if functionalism were true then reliance on evidence for one's PC would not guarantee that one actually does have PC. Someone who wishes to successfully object to skepticism about their PC as in (e2) must make the following argument:
(1) if functionalism is true, then it would be impossible to verify the existence of PC in others and in one's own case
(2) functionalism is false for some reason R, where R is not reliance on any evidence for possession of PC.
(3) therefore, skepticism about qualia is unwarranted
Notice, in the above argument, that functionalism must be objected to for some reason R where R is not reliance on any evidence for possession of PC. There are a number of aspects of functionalism that could potentially be objected to. My project has been to show that the 'absent qualia' objections, in light of what such objections imply, can not be successfully made against functionalism. Arguments against functionalism that posit 'absent qualia' as being possible within functionalism have the unintended consequence of making functionalism immune to such objections.
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