A Response to Functionalism
Stephen Priest in Theories of Mind Chapter 5 describes functionalism as 'the theory that being in a mental state is being in a functional state' and adds that 'functionalism is, in a sense, an attempt to bypass the mind-body problem'. What does this definition really mean? An analogy might clarify the situation.
Suppose a young child were to ask me what a saucepan was and in reply I said that it is a means of holding soup or vegetables in water during the time in which they are heated to make them ready for eating. Any eavesdropping adult might wonder why I did not describe it directly, use terms like hollow metal cylinder, the size of a human head, with a handle, that is, describe what it actually looks like not what it does. Even better, he might think I should have gone into t.., kitchen and fetched a saucepan for the child to look at. If I showed him the saucepan, and indeed, if he saw it in use, no further explanation would be necessary.
I assume that functionalism arose and gained adherents because those philosophers working in the mind-body area came to the conclusion that definitions of mental states which were direct and precise were unattainable for the following reasons: first, that whereas a saucepan can be described in uncontentious language, the same is not true of mental states; second, that whereas one can point to a saucepan to reinforce the description, there is no such possibility in the case of mental states.
What, then, does functionalism have to say about mental states? The term 'functional' describes the role of mental states in a series of causal relations. A mental state is caused by an antecedent event and a mental state is itself the cause of subsequent events. The antecedent event is physical; them subsequent events are both physical and mental. For example, I observe someone stub his toe against a doorway, cry out, rub his toe and curse his own clumsiness. Here the antecedent event is the physical collision of solid oak door jamb with tender flesh. The effect of this cause is the mental state of pain and this has consequences of two types. One is physical or behavioural, the crying out 'ouch', the rubbing of the stricken toe and the uttering of the curse. The other is mental, perhaps the emotion of embarrassment, perhaps an unspoken intention to ditch the open-toed sandals and wear boots around the house. The functionalist, though he may be a thorough-going materialist, does not necessarily (by virtue of being a functionalist) deny that the mental state is distinct from the brain state, but has taken the position that the ontology of mental states is either inaccessible to philosophical enquiry or of no philosophical interest. Here is another example. Having just pegged out the washing, I see grey clouds gathering and spots of rain on the window. I go out and collect in the washing. What is this situation like according to a functionalist description? The initiating physical event is the image of grey cloud and raindrops impinging on my eyes. The mental event is the expectation of damp washing made even wetter. The consequences of the mental event are a) physical: my actions to fetch in the washing and b) mental: a feeling of disappointment or frustration.
Ostensibly, as I implied earlier, functionalism is compatible both with materialism and with dualism. In the former case, if mental states are reducible to physical states the links between the stages of the causal series are not problematic since the effects of matter impinging on matter can be described in accordance with known physical laws. Under these terms there is no difference in principle between a causal chain of reactions when colliding balls are dispersed on a snooker table and a series of events which include a mental state. If, however, mental states prove to be ontologically distinct from physical states, then any interaction requires some framework of explanation. Briefly, at this stage, there needs to be a theoretical underpinning to the claim that a non-physical entity might have a causal effect on a physical entity, and vice-versa as well. I will return to this crucial point.
Part of the appeal of functionalism is that it turns a blind eye to ontology; it is not interested in what a mental state is only in what a mental state does. David Lewis uses the example of the Martian.. Imagine that we first pinch this extra-terrestrial being and then see him writhing about on the ground and groaning. Does the Martian feel pain? Does he experience a mental state? 11' we apply the functionalist criteria then it appears that he does. We have observed typical pain inducing behaviour, the body being pinched, we have observed typical behavioural consequences of pain in his writhing and groaning. This is after all no different from what we observe in our fellow humans. Their pain itself is never the direct object of our observation but always inferred from it. If we assert that human beings are in pain on the basis of pain-inducing events and of pain behaviour, then, on functional grounds, it seems equally plausible to assert that the Martian is in pain. However, when the Martian is closely examined under a brain scan, it is revealed that, unlike human beings, he has no nervous system but instead hydraulic system of fluid-filled cavities'. There is nothing unique about human (or animal) brains, therefore, which makes them an essential requirement for the presence of pain. Human brains serve a function which can be performed equally well by other mechanical systems.
Is it the case that ontology is insignificant in understanding a causal series. Only within limits surely? In the Martian thought experiment the hydraulic system performs a linking role between pain inducing events and the pain behaviour. There n -my be other alternatives but the scope is certainly not unrestricted. Presumably the hydraulic system works as a receiver and transmitter in the sequence of events, from input to output. But not everything could assume this role. If the Martian's head contained candyfloss or Coca Cola, the receiving and transmitting process would not operate. Suppose the fan belt on my car breaks during a journey. A stop gap would be a pair of tights which could be fastened in place of the fan belt and last long enough for me to reach my destination. A pair of tights s now performing the function, of the fan belt. A police patrol driver, if he were of a functionalist cast of mind, might well guess the number of cars passing which had unconventional fan belts and conclude that since they did the same job within the engine, it was on no importance what drove the alternator. But consider another scenario. I am on the motorway; my car is overheating and the fan belt is broken. This time there is no one wearing tights in the car. Most of the items I have to hand in the car an AA book, a spare wiper blade, a rubber mat, yesterday's newspaper would be quite useless in my emergency. Why make this obvious point? It shows that ontology is important; it cannot be ignored. A particular function can only be performed by a limited number of items which have certain necessary properties. I can cut my grass with a scythe, with an old-fashioned push mower, with a petrol-d-riven mower or a rotary hover. I could even buy a sheep? But I could not do the job with a rake, a hair dryer or a Black and Decker drill.
It is, therefore, necessary to determine what something is before a functional role can be ascribed to it. It follows that mental states cannot be given a function and certainly not defined in terms of their function until it has first been established that mental states, because they have the necessary properties, are capable of carrying out that particular function. If a door-to-door salesman tried to interest me in a revolutionary new lawn cutter, a rational response would be to ask him to describe how it worked and better still to show me the novel device. I would be looking for an object which had some version of a cutting edge (like the blade of a mower or the teeth of a sheep). If all he provided was a spray can or a brush, I would close the door very quickly-
Do mental states have the necessary properties with which to perform a functional role in a causal series of events? This is the very question on which functionalism remains silent. It is one thing to remain silent in an area 'whereof we cannot speak', but about a subject of which we have direct experience such reticence seems perverse. Stephen Priest in the final chapter of Theories of the Mind lists the predicates of the mental and physical in two columns:
This a convenient gathering together of the contrasting properties traditionally attributed to the -two sides of the dualist dichotomy. It is not necessary to examine here the validity of each pairing since my point is based on a small section of the list.
Functionalism avoids direct description of mental states but, as I have shown, its conclusions derive from hidden assumptions about the nature of mental states. Since we do have access to mental states and can infer their properties, it is possible to assess whether they have the capacity to perform the role functionalists ascribe to them. To the functionalist mental states are interactive with physical states both as causes and effects. Let me isolate two of the properties, listed above, of mental states. A mental state, for example, a pain or an intention, is shapeless and unextended, that is, it has no dimensions. If the functionalist scheme is to work, then when I stub my toe, there is physical activity within my body involving flesh, nerves in the spinal column and neurons in the brain. This activity takes place in entities which are extended and measurable in terms of length, breadth, depth, volume, mass. The subsequent pain and intention are mental states which cannot be described in the same terms. There is no method by which a sharp twinge of pain can be subjected to any techniques of measurement which would put it into the same category as the physical state which preceded it. It is absurd even to think of a pain as having a length or mass or any dimensions accessible to methods of mensuration. This clear distinction (not to mention others of Stephen Priest's list) is sufficient to render the concept of causal interaction between mental and physical (in either direction) as deeply problematic to say the very least. The prospect of cutting a lawn with a hairdryer seems surprisingly plausible now in contrast with the implications of functionalism. As I said at the beginning, functionalism is a doctrine devised to bypass the mind-body problem. Of course, implied in the very idea of a bypass, if I take the metaphor a little more literally than is probably intended, is that it is an alternative to going into the town centre, not an exclusive replacement. The Newbury bypass does not cut off access for anyone intending to visit Newbury itself. On similar lines, defining mental states in terms of their alleged function presents no case against direct confrontation with mental states, that is, describing their properties as directly experienced, as I have tried to do.
Furthermore, consider the wider implications of functionalism. Indeed, the dominant world view of our age, rooted as it is in physical causality, would have to be torn up since the underlying belief that physical events have only physical causes is contrary to the full consequences of the functionalist position. The brain, for example, turns out to be a very strange, hybrid, physical object. Although it is composed of cells whose workings are well monitored by biologists and although those cells are composed of molecules and atoms whose motions are the well documented study of physicists, it is revealed now to have two distinct and alien modes of operation. First, many of its processes would be in conformity with laws of physics, that is, viewed as predictable electrochemical activity traceable by scans etc. Second, however, many of its processes would have causes inherently not only invisible but undetectable. For according to functionalism, some physical (neural) states are caused by mental states. Since these mental states have neither shape, dimension nor spatial substance, then no measuring instrument would be able to identify them. Scientific instruments are responsive only to physical presence; mental states are by definition outside their range. Neuroscientists would observe some brain changes to have physical causes and some to have no physical cause whatsoever very strange phenomena. The concept of invisible forces acting on the physical world is not new, of course. It belongs to a very ancient tradition which goes under the name of magic. If the distinction between physical and mental is indeed as I have outlined and if the functionalist insists on mental/physical interaction, then we should look forward to a new age of witchcraft and alchemy and be as ruthless with scientific text books with their underpinning assumption of the universality of physical laws as David Hume proposed with 'any volume of divinity or school metaphysics', that is, they should be committed 'to the flames'.
My case may well be criticised on the grounds that it falls into the trap of Cartesian dualism which functionalism very carefully tries to avoid. Materialism, double-aspect theory and functionalism are responses to the perceived failure of dualism 'in to resolve the very difficulties it creates. For the more dualists stress the contrasting properties of mind on the one hand and matter on the other, the more difficult it becomes to understand any interactions between them. There is clearly a contradiction in a doctrine which defines mental and physical in terms that both make them mutually exclusive and yet place them in a causal relationship. Perhaps there is more plausibility in a solution which maintains a dualistic separation without interaction, a form of parallelism.