However, whereas Suber is a professional academic, I am not. Before reading any further, read my disclaimer and warning on my My Writings page.
The
Painful Truth About Madmen and Martians?
Glenn Mason-Riseborough
(23/6/2000)
1.0 Introduction
Let’s start with some background. David Lewis tells us two stories about pain in “Mad Pain and Martian Pain.”[1]
Firstly, Lewis tells us about a possible man (the madman) whose pain differs greatly than ours does in its causes and effects. This man’s pain is caused by moderate exercise on an empty stomach, and as a consequence forces him to concentrate on mathematics at the expense of all else. Why is the madman in pain? Well, it’s because this man, as a member of the human species, is wired up neurophysiologically the same as other humans, and the parts of his brain that process the mild exercise inputs and mathematics concentrating outputs are the same, in location and action, as the parts of the brains of typical human beings that process pain as we typically perceive it (inputs: cuts, bruises, pinches, etc; outputs: writhing, groaning, avoidance, distraction, etc). The man is feeling pain because if a neurologist examined his brain, the neurologist would not be able to distinguish this man’s neuro-chemical processes in this situation with the neuro-chemical processes of humans who have the more typical pain stimuli and responses.
Secondly, Lewis tells us about an alien (a Martian) who feels pain as we do, but does not have the same physical structure as us. The Martian has cavities throughout his body that can fill with fluids. When the cavities in the Martian’s feet are filled, he is in pain. Why is the Martian in pain? Well, it’s because his pain is caused the same way as ours typically is – by cuts bruises, pinches, etc, and he responds as we typically would – writhing, groaning, etc.
Lewis thinks that both of these stories are possible, that both the madman and the Martian are in pain (though perhaps in different senses), and that a good theory of the mind needs to account for both of them by saying that both the madman and the Martian are in pain. Unfortunately (according to Lewis), most theories do not. Either they do not account for madmen or they do not account for Martians. Thus challenged, Lewis sets out to give a satisfactory account of the mind that deals with both types of pain. In other words, Lewis’ theory of the mind tries to deal with both the empirical functionalist’s and the analytic functionalist’s claim about mental states – trying to incorporate their respective good points and avoid their respective bad points. Thus, Lewis attempts a hybrid functionalist view, which in his words “wriggles through between Scylla and Charybdis.”[2]
My aim in this essay is to focus primarily on Lewis’ putative theory of the mind, but also provide a general survey of the differences between empirical and analytic functionalisms, and the programme of developing a hybrid version. Firstly, I’ll give a brief survey of the different types of functionalism available; secondly, I’ll focus on Lewis’ hybrid theory of the mind, its problems, and whether it ultimately succeeds.
2.0 Functionalism in a Nutshell
In the field of Philosophy of Mind, there are various forms of functionalism put forward. How are we to distinguish between them, and, if we are to be a functionalist, which form of functionalism should we accept? One broad way of categorising functionalism is to distinguish between analytic (or commonsense) functionalism and empirical functionalism. The latter itself is divided into a number of different forms, and David Braddon-Mitchell and Frank Jackson[3] give us a useful breakdown of the many varieties. The essence of the difference between the two types of functionalism is the approach taken to the knowledge constraint. That is, how they approach the task of falling into line with our common-sense ideas about mental states and the fact that we all seem to know what we are talking about when we talk about pain, for example. Analytic functionalism tells us that the folk roles give the meaning of the mental state terms. That is, it is a theory about the mind that follows our folk intuitions and thus it says that to be in some mental state is to be in a state that fills the folk role associated with that state. Empirical functionalism has folk roles fix the reference. Lewis’ story about the madman and the Martian given above show us the respective focus of each type of functionalism. Because the analytic functionalist focuses on the folk roles as giving the meaning of the mental state, it is a theory that is especially sympathetic to the Martian. The Martian example follows our folk intuitions about typical pain stimuli and responses, and thus tells us that the Martian is in pain. But analytic functionalism doesn’t tell us that the madman is in pain, because the madman is not in a state that occupies the causal role of pain for him. Most types of empirical functionalism are lacking in precisely the other direction. Because they reference-fix on the state that plays the role, they tell us that the madman is in pain (he is in the correct neurophysiological state) but they do not tell us that the Martian is in pain (he is not in the correct neurophysiological state, because he has no neurophysiology). Other types of empirical functionalism attempt to overcome this type of chauvinism. While they are still types of empirical functionalism because they reference-fix, they do not reference-fix on the state itself, but rather on further functional roles, based on whatever the appropriate sciences tell us.
3.0 A Closer Examination of Lewis’ View
In Lewis’ words, his wiggling between Scylla and Charybdis involves a “widespread sort of ambiguity,”[4] but according to him it is a justifiable sort of ambiguity. The view that Lewis defends in “Mad Pain and Martian Pain” is that the concept of a mental state is the concept of a state that typically occupies a certain causal role for a population. The ‘typically’ qualification is an important qualification and it is the addition of this that allows for the madman. Equally, the ‘for a population’ qualification is an important qualification and it is the addition of this that allows for the Martian.
In the case of the madman, although he is not in a state that occupies the causal role of pain for him, he is in the state that typically occupies the causal role for his population. That is, when we examine the neurophysiology of the human population, we discover that what we refer to as pain typically corresponds to certain neurons firing in certain parts of the brain, let’s call these neurons C-fibres. So, for humans, when we have the typical pain inputs and outputs, it is also typically the case that our C-fibres are firing. Thus, for humans pain is C-fibres firing. But the madman is an exception. Even though the madman’s C-fibres are firing, it is not the state that occupies the role of pain for him. According to Lewis this doesn’t matter. On Lewis’ view since the madman is a member of the human population, and for humans pain typically is C-fibres firing, this still means that the madman can still rightly be said to be in pain.
So what about the Martian? The important point that Lewis wants to argue for is that the concept of pain is a non-rigid concept. That is, even though for humans pain is C-fibres firing, it need not be the case in other worlds or for other populations. Lewis argues that it is a contingent matter than in our world, for our population, pain is C-fibres firing. Thus, it is possible that there may be other worlds or other populations in which a different state occupies the same role for those beings. In the case of the Martians it is the inflation of certain feet-cavities that is pain instead of C-fibres firing. This is because when Martians are examined, for most Martians it is feet-cavities inflating that occurs when Martians have the typical pain inputs and outputs. That is, for Martians pain is feet-cavities inflating. The Martian is in pain because he is a typical member of the Martian population and he is in a state that typically occupies the causal role of pain for a Martian population.
3.1 Potential Problems for Lewis’ Theory
I’ve got two main sets of worries with Lewis’ theory of the mind. The first is a fleshing out of the ‘typically’ and ‘population’ qualifications; the second is a questioning of the assumptions that a credible theory of mind must deal with both the madman and the Martian.
3.1.1 Just what is a Typical State for a
Population?
The first worry I’ll consider in this set of problems is one that Lewis discusses. This is the problem of pain in a being that is mad, alien and unique. Since this being is a unique alien it is the only member of its population, and thus if we are to know what typically occupies the causal role of pain in his species, then we are going to have to examine just him. But the problem is that he is, by hypothesis, mad, and thus an exception, and thus as an atypical member he is not a good candidate for examining what occupies the causal role of pain in his population. According to Lewis’ theory, we could never know when he was in pain. Lewis responds to this problem by denying that it is possible, and claims that we need not solve the problem. It is fair to say that this reply doesn’t satisfy me. If we are prepared to talk about madmen or Martians[5], then I see no great leap in also being prepared to talk about mad unique aliens. So I see this as a problem for the theory, but let’s move on.
The next worry to consider is if the alien is not unique, but he is a member of a population in which half of this alien population have a certain state that occupies the pain role and the other half has a different state. To continue the Martian example, we might say that for half the Martian population left-foot-inflations are caused by cuts, etc and the reaction is to groan, writhe, etc, whereas right-foot-inflations are caused (much like the madman) by moderate exercise on an empty stomach and in turn cause mathematics concentration. But, for the other half of the population the situation is reversed – that is, left foot for mad pain and right foot for normal pain. In this case, what would we say is the typical state that occupies the pain role for Martians? Is it left-foot-inflations or right-foot-inflations? There are two possible solutions, both equally unpleasant. The first is to say that in the Martian population, half of the Martians are mad. Which half? Well, take your pick. Whichever way it is decided, it seems highly prejudiced (footist?). The second solution is to say that there are actually two separate populations, and we can generate ‘typically conditions’ for each separately. This alone might suffice, but it leads us on to the next worry in this set of problems.
The final worry in this set of problems centres around the issue of determining exactly what a population is, and it is going to turn out to be very arguable just how inclusive or exclusive we are about populations. At the one extreme we could say that there is only one universal population, and this includes all beings that have states that occupy the pain role (for example). This would mean that if there were six billion humans, but only six million Martians (and no other sentient beings), the state that typically occupies the pain role would be C-fibres firing. Since Martians don’t have C-fibres, they would not feel pain. Conversely, if there were six trillion Martians then humans would not feel pain. Essentially this view reduces to a form of empirical functionalism that suffers from chauvinism (though it would not necessarily be a human chauvinism). At the other extreme would be the view that there were as many different populations as there are beings with causal roles for pain. On this view, since all beings would be unique to their population, we could either say that we cannot know whether anyone is in pain (much like the mad unique alien), or we could essentially reduce it to analytic functionalism, work with the assumption that there is no mad pain, and everyone fulfils their respective ‘typically’ qualification. Both these extremes have some initial plausibility, based on whether we see similarity between beings that have pain, or differences between beings based on very specific differences (finger(tenticle)prints maybe?). In between we have got a range of more moderate options such as differentiating based on planetary origin (Martians, Earthlings, etc), or on genus (apes, humans, Martians, etc), or any number of possible combinations. Presumably, it is one of these articulations of moderate population-definitions that Lewis wants, but it is difficult to pick one without being ad hoc about it.
So, the problem with Lewis’ ambiguous theory is that it is a little too ambiguous, and not in a good way. When we spell it out in more detail it loses plausibility because it is open to many different interpretations, and which way we lean is mostly arbitrary. Depending on which way we cut populations, we are going to get some very different answers to whether a particular being is in pain.
3.1.2 Is the Approach all Wrong?
This next set of objections might be thought of as prior to the previous set, in that it questions Lewis’ assumption that a credible theory of the mind needs to make a place for both the madman and the Martian. Daniel Dennett’s short piece entitled “Cow-sharks, Magnets and Swampman”[6] is my starting point, and I take inspiration from Dennett, Paul Churchland, Ruth Millikan, David Papineau,[7] and others who all question the wisdom of placing so much emphasis on folk psychological intuitions on any matter. As I see it, it is a very contentious position indeed to start out assuming that our account of the mind must make room for both madmen and Martians.
Dennett sets out by questioning the whole approach of providing fantastic thought experiments to prove conceptual points. Dennett’s main point is that maybe all these thought experiments don’t generate anything useful anyway. He gives an example of magnets. He tells us that there could be two competing candidates for the truth-maker of magnets – (a) all magnets are things that attract iron, or (b) all magnets are things that have a certain internal structure (call it M-alignment). Does (b) supersede (a), or does (b) merely reductively explain (a)? To answer this Dennett suggests asking the following two questions: (1) suppose you discover a thing that attracts iron but is not M-aligned – is it a magnet? Or (2) suppose you discover a thing that was M-aligned but did not attract iron – is it a magnet? Dennett’s answer is that if the physicists were asked this, they would probably reply that they had more important things to worry about than what to call these theorised objects. Dennett’s response is slightly flippant, but I think it is one that has some justification. Dennett’s point is that the scientific picture, based on observed regularities, tells us that there is a deep regularity between the alignment of atomic dipoles on magnetic domains and iron-attraction. The logical possibility of this breaking is of little interest, and our theory of magnets does not and need not base itself on mere logical possibility.
This same conclusion might be made regarding the madman. While it is true that it is logically possible for Lewis’ madman to exist, as I see it, it is not within the realms of current neuroscience. Thus, if Dennett’s point holds, deciding whether a madman is in pain or not is of little interest. In defence of Lewis, I take it that Lewis is motivated by the discoveries in cognitive neuroscience that there is a certain amount of plasticity in the brain, and to a certain degree, especially in younger children, different areas of the brain can adapt to perform certain new vital functions. Consider for example cases of hemispherectomy, or alternatively cases in which slow-growing tumours or very slow hydrocephalus cause brain matter to gradually atrophy. In cases of the former if the patient is young enough or in cases of the latter if the atrophy is slow enough, other parts of the brain take over functionality of the damaged parts. Thus, some types of madmen could exist, in the sense that there might be some people with parts of the brain performing different functions than most of the rest of the population (and just maybe the exercise input and mathematics concentrating outputs could be explained through behavioural conditioning). But, the big problem is that a credible neuroscience doesn’t just look at just the central nervous system in isolation, but also at the peripheral nervous system, and surely, in this light it is just physically impossible for the same neurons to fire and in one case be typical pain and in an identical case be mad pain. Lewis’ madman might be logically possible, but is not physically possible and as I see it, quibbling over whether he is pain or not is of very little interest or importance. When it comes down to deciding if pain is the state of having certain specified neurons firing, or instead is the state of having certain specified stimuli and responses, then this just becomes an argument over definitions.
A more general criticism that Dennett, Churchland and others put forward is that too much weight is often placed on the role of intuition. Lewis’ approach exemplifies this, with his starting point being that we need to account for our intuitions regarding madmen and Martians. These thought experiments work by keeping some things constant and reducing other things to zero. In the case of the madman the constant is the neurophysiology while the change is the inputs and outputs; in the case of the Martian the constant is the inputs and outputs while the change is the neurophysiology (or lack thereof). The essential problem according to Dennett is that the dependant variable is supposed to be intuition, yet intuition is very hard to control, and indeed it turns out to be misleading and wrong in numerous situations. As Dennett[8] tells us, modern academic psychology tells us facts about the mind that go against some very strong folk intuitions. One such example is vision, which, when tricked by various illusions (such as the Ames’ room, Ponzo Illusion, Müller-Lyer Illusion, seeing eye pictures, etc) shows us that reality goes against our naïve expectations. More exotic examples of counter-intuitive deficits include split-brain phenomena, hemineglect, and various agnosias, aphasias, and amnesias, which many books of neuropsychological case studies tell us about.[9] In all of these cases modern academic psychology tells us facts about the mind that are contrary to our folk psychological intuitions. On a more positive side, those who have synaesthesia are often met with incredulity by those who do not experience it,[10] and (arguably positive), hallucinogens will often show up facets of the mind that go against everyday understandings.[11] What this means is that it is possible to cast doubt on the supposed inerrancy of folk intuitions, and that relying on intuitions regarding madmen and Martians is very dubious. In the case of the madman, I do not think it is even a strong intuition that he would be in pain, and as I suggested above, Lewis’ intuition is based on some dubious neurophysiological conclusions (to me it seems more correct to call the madman an analytic functionalist’s intuition rather than a consequence of empirical functionalism). In the case of the Martian, how do we really know that we are even correctly imagining a Martian in the correct sense when we are claiming that it would feel pain? It seems conceivable that our intuitions are being misled because we are unable to completely divorce our image of a Martian with our image of a human being, and we are still half thinking of him as a human.
4.0 Final Words
Much of this paper has focused on critiquing Lewis’ attempt at giving a functionalist explanation of both mad pain and Martian pain. As is no doubt clear, I don’t think he succeeds. No only is it the case that when we try to pin it down it turns out to be far too ambiguous to be useful, but it seems to me that the approach is misguided. Lewis’ view is too close to analytic functionalism and it inherits all the flaws (as I see it) of paying too much attention to the folk psychological intuitions. Lewis is nearer to analytic functionalism when he talks about a state that occupies a certain causal role. When Lewis incorporates some empirical functionalist parts to the theory in focusing on the typically clause and the possibility of madmen, this results in doubtful neuroscience. So, it seems to me that Lewis’ functionalist theory of the mind, rather than incorporating the advantages of analytic and empirical functionalism, it has incorporated the disadvantages of both.
Bibliography
Braddon-Mitchell, D. & Jackson, F. (1996). Philosophy of Mind and Cognition. Cambridge, MA: Blackwell.
Churchland, P. M. (1990). Eliminative Materialism and the Propositional Attitudes. In W. G. Lycan (ed.), Mind and Cognition: A Reader, (pp. 206–223). Oxford: Blackwell.
Cytowic, R. (1994). The Man who Tasted Shapes. London: Abacus.
Dennett, D. (19??). Why You Can’t Make a Computer that Feels Pain.
Dennett, D. (1991). Consciousness Explained. Boston: Little, Brown and Company.
Dennett, D. (1996). Cow-sharks, Magnets, and Swampman. Mind & Language, 11(1), 76-77.
Fodor, J. (1990). Banish DisContent. In W. G. Lycan (ed.), Mind and Cognition: A Reader, (pp. 399–420). Oxford: Blackwell.
Horgan, T. & Woodward, J. (1990). Folk Psychology is Here to Stay. In W. G. Lycan (ed.), Mind and Cognition: A Reader, (pp. 420–438). Oxford: Blackwell.
Huxley, A. (1963). The Doors of Perception, and Heaven and Hell. New York: Harper and Row.
Lewis, D. (19??). Mad Pain and Martian Pain.
Millikan, R. G. (1993). White Queen Psychology and other essays for Alice. Cambridge, MA: MIT Press.
Ogden, J. (1996) Fractured Minds: A Case-study Approach to Clinical Neuropsychology. New York: Oxford University Press.
Papineau, D. (1987). Reality and Representation. Cambridge, MA: Blackwell.
Phillips, H. E. (1995). Vicissitudes of the I. Englewood Cliffs, NJ: Prentice Hall.
Sacks, O. (1985). The Man who Mistook his Wife for a Hat. London: Duckworth.
[1] Lewis, 19??.
[2] Lewis, 19??, p, 124.
[3] Braddon-Mitchell & Jackson, 1996.
[4] Lewis, 19??, p. 124.
[5] A big if, and I will ague against later.
[6] Dennett, 1996.
[7] Dennett, 19?? & 1991; Churchland, 1990; Millikan, 1993; Papineau, 1987.
[8] Dennett, 1991.
[9] See for example Ogden, 1996 and Sacks, 1985.
[10] See for example Cytowic, 1994.
[11] See for example Huxley, 1963.