Eliminative Materialism and The Propositional Attitudes (1981) By Paul Churchland Eliminative materialism is the theory that common-sense folk psychology is false and must be replaced by, not reduced by, completed neuroscience. A completed neuroscience will integrate better within the physical sciences, than FP as well. As Chruchland sees it, earlier objections to materialism focused on qualia- he claims that these barriers are now dissolving. More recently, objections to materialism have focused on the problem of intentionality, arguing that beliefs and desires cannot be reduced to or eliminated in favor of something material. To examine the position why beliefs and desires cannot be eliminated for something material, Churchland begins by considering folk psychology to be a theory. Jokingly, Chruchland remarks that it is surprising that FP faces so many objections, for common sense has yielded so many theories like space has a preferred direction in which all things fall and that weight is an intrinsic feature of a body and so on. While the latter have clearly been shown to be false, people still tend to hold onto to FP because of the tendency to give up a theory of common sense only when (1) it becomes safely located in antiquity; (2) it is shown that the theory is so false that its speculative nature cannot be escaped. PART 1: Folk psychology as a theory If we consider folk psychology as a theory, it is possible to unite the most important problems in philosophy of mind: The explanation and prediction of behavior All of us can explain and also predict the behavior of other people and even animals rather easily and successfully. In these explanations and predictions, we attribute beliefs and desires to others. Explanations and predictions presuppose laws. Churchland believes that rough and ready-made common-sensical laws can be reconstructed from everyday folk-psychology explanations. Each of us understands others because we share a command of an integrated body of lore which concerns the law-like relations holding amongst external circumstances, internal states and behavior. This body of lore constitutes ‘folk psychology’. The problem of meanings of our terms for mental states If folk psychology is a theory, then the semantics of our terms is understood in the same way as the semantics of any other theoretical terms. That is, the meaning of a theoretical term is derived from a network of laws in which it figures. The problem of other minds We cannot infer that others have mind from their behavior and it is risky to make such a generalization from our own case. Rather, the belief that others have mind is an explanatory hypothesis that belongs to folk psychology and it has been successful in providing prediction, understanding and explanation of the individual’s continuing behavior, in comparison to other competing hypotheses. For this reason, FP is a reasonable belief. The principles of FP can be used by any person and ascribed to our behavior to explain, predict or understand it without depending on knowledge of one’s own mind. The intentionality of mental states The propositional attitudes form the systematic core of FP. For many philosophers, the intentionality of mental states marks a fundamental contrast with what is merely physical. The intentionality of mental states is not a mysterious feature but rather a ‘structural feature’ of the concepts of folk psychology. These structural features of FP are to show how much folk psychology is like theories in physical sciences. For instance, he compares the propositional attitudes- has a belief that p, a desire that p etc- with what he calls the ‘numerical attitudes’- has a mass n, velocity n and others. Both the numerical and propositional cases have predicate forming expressions. In the numerical case, we substitute the number for ‘n’ to form a predicate. In the propositional case, we substitute a proposition for p to form a predicate. For instance, believes that Tom is tall. In both cases, the logical relations that hold among the attitudes are the same as those that hold among their contents. That is, the logical relation of the numerical attitudes of mass with ‘n’ same as relation of mass with 7 (that which replaces n) corresponds to relation of propositional attitude of belief/desire with ‘p’ as relation of belief to ‘Tom is Tall’. The structure of propositional attitude and numerical attitude correspond to one another. Propositional attitude Numerical attitude Belief ‘p’ Mass ‘n’ Belief Tom is tall Mass 7 In both cases, we can form laws by quantifying- ‘for all n’, ‘for all p’. For instance, In numerical attitude: (x)(f)(m)[((x has a mass of m) & (x suffers a net force of f)) (x accelerates at f/m)] In propositional attitude: (x)(p)[(x fears p) (x desires that ~p)], (x)(p)[(x hopes that p) & (x discovers that p)) (x is pleased that p)] The only difference between folk psychology and theories in physical sciences is in the sort of abstract entities it utilized: propositions instead of numbers. Mind-body problem In calling folk psychology a theory, the mind-body problem becomes the problem of how the ontology of one theory (FP) relates to that of another (completed neuroscience). The different philosophical theories reflect different positions on the reduction of folk psychology to neuroscience (of what could happen of FP): Identity theory maintains that there will be a smooth reduction that preserves the ontology of folk psychology. The ontology of FP will be preserves through identities. Dualism says that it will be irreducible, since it deals with a non-physical domain. Functionalism says that it will be irreducible, since psychology deals with an abstract set of relations among functional states that can be realized in different media and therefore, cannot be reduced to neuroscience which only deals with principles peculiar to human physical arrangement. Eliminativism says that folk psychology won’t be reduced to neuroscience because it is wrong and will be replaced by neuroscience. PART 2: Why folk psychology might be false Given that folk psychology is an empirical theory, there is at least a possibility that it is false and that its ontology (beliefs, desires) is an illusion. However, this possibility is only seriously taken by eliminativism currently. To judge if FP is a success or failure, we need to see three things: 1. FP’s explanatory failures and successes FP cannot explain many “central and important mental phenomena” like function of sleep, creative imagination, 3-D vision from 2-D retinal array, difference in intelligence, perceptual illusions and learning (especially in pre and non-linguistic organisms like babies and animals). FP faces special difficult in case of accounting for learning because its concept of learning as manipulation and storage of propositional attitudes is not adequate as it doesn’t explain how these occur. These failures don’t prove that FP is false but raises doubts about it being a highly superficial theory. 2. FP’s long-term development as a theory FP has a history of ‘retreat, infertility, decadence’. We used to ascribe intentionality to all sorts of things in nature (anger to wind, jealousy to moon and so on) but even if we restrict its application just to humans, no advancement has been made for thousands of years. FP of the Greeks is the FP of today. Perfect theories have no need to evolve but FP is imperfect as is visible from its explanatory failures. Churchland sees it as a ‘degenerating research program’. 3. How well FP fits in with rest of science in light of recent findings about us We may hold onto to a stagnant theory in the science if it is the only theory that fits well with related sciences- if it has theoretical integration. However, Churchland finds that FP fairs poorly here as well. We can approach homo sapiens safely from the side of particle physics, biology, physiology, evolutionary theory and materialistic neuroscience which are providing answers to questions about human sensory input, neural activity and motor control. He claims that FP is not part of this growing synthesis and doesn’t fit in with science like evolutionary theory, biology and neuroscience. The intentional categories used cannot be reduced to the larger corpus that has arisen today. It is mandatory for a theory to fit in with these as they are part of growing system of knowledge which also includes physics and chemistry. FP looks as alchemy looked when elemental chemistry was coming up, as Aristotelean cosmology looked as classical mechanics came into being. We favor FP only because it seems to help with our ‘interpersonal commerces’. However, without this favorism, we can see that FP is a failing theory which cannot be considered valid without serious questioning of its foundation and development. PART 3: Reasons why FP should not be eliminated In defense of FP, it is claimed that FP is not an empirical theory which is refutable by facts. The following arguments are generally raised by functionalists. 1. FP is a normative theory. FP doesn’t describe how people actually act, but characterizes an ideal of how people ought to act if they were to act rationally on the basis of beliefs and desires. Though human beings may not be able to achieve the level of rationality required, it does not mean that FP is not normative. Moreover, even in considering FP as descriptive, we can see that our activities can be understood usefully and carefully as rational within the FP framework except for certain conditions like noise, interference or other breakdown. Hence, FP cannot be replaced by a description of what’s going on at neuronal level since rationality can only be defined in the FP framework of propositional attitudes like beliefs and desires. This has been the view of Daniel Dennett. The normative characterization is used by Karl Popper and Joseph Margolis. 2. FP is an abstract theory: According to functionalists, FP characterizes internal states such as beliefs and desires in terms of a network of relationships to sensory inputs, behavioral outputs and other mental states without reference to our physical constitution. Churchland considers our physical constitution to be our intrinsic nature however. Functionalists argue that this abstract network of relations could be realized in a variety of different kinds of physical systems and therefore, we cannot eliminate this functional characterization in favor of a physical one. Both of these defense try to shift the onus of burden of proof- from trying to show that FP is a good theory of mind, they show that certain physical systems are capable of supporting FP. They show as if the empirical systems are to show that FP is faithful to them, than of FP to show how it can faithfully describe the internal activities of these empirical systems. This mistake is visible in the examples used by functionalists like mousetraps, robots, valve-lifters which are constructed to fit a preconceived bill. Thus, if any failures arise, it is blamed on incapacity of the physical system than on the functional characterization. Not all functionalists defend FP in this way, for instance, Jerry Fodor doesn’t. Fodor wants to find the best possible functional characterization of the mind, which is an empirical question for him and the answer may not be our current FP. Nevertheless, Fodor still sees some sort of abstract theory that explains our cognitive activity in terms of manipulation of propositional attitudes. Fodor thinks that whatever corrections functionalist psychology makes to FP, it will not be replaced with any sort of physical theory. Churchland thinks that the way to defend eliminativism against functionalism is by showing the shortcomings of functionalism. PART 4: Against the argument that FP is an abstract theory Churchland argues against functionalism in philosophy of mind by drawing an analogy with alchemy. Alchemy explained the properties of matter in terms of four different sorts of spirits (mercury, sulphur, yellow arsenic and sal ammoniac). Each of these spirits was held responsible for a rough but characteristic syndrome of sensible, combinatorial and causal properties. For instance, the spirit of mercury explained the shininess of metals. This theory was dead by the time Lavoisier and Dalton’s theories of atoms and elements arose. An elimination of alchemy took place. The dualistic interpretation of the four elements as spirits would have been feeble and pointless. A reduction would have been impossible, because the old and new gave different classifications of things. However, suppose that these spirits had been defined as functional states. For instance, being ensouled by mercury just is the disposition to reflect light. Defenders of alchemy could have claimed that it deals with abstract level of description that does not reduce to the atomic level. For Churchland, this analogy shows that it is at least possible for the sort of moves the functionalist makes to result in an outrage against truth and reason. One could imagine similar defenses of outmoded theories like phlogiston, vital spirits, four humors and others. The functionalist stratagem can be used as a smokescreen for error. Thus, it is not enough to call FP an abstract theory to prove that it is not false. The same defense of being abstract could have been made for any haywire network of internal states. The defense begs the question in assuming that the intentionality as explained by FP captures what is important in cognition. Finally, eliminativism is consistent with the claim that a cognitive system must be explained in terms of functional organization of its internal states. It’s just opposed to FP. PART 3: Against the argument that FP is normative theory 1. Just because FP explanations depend upon logical relations among beliefs and desires does not make FP a normative theory. In the same way, the mathematical relations between the quantities in classical gas law do not imply that this law has a normative character. The logical relationships among propositions in FP are objective. The normative element comes in because we value these patterns of reasoning, though we do not value all of these patterns. 2. FP ascribes only a minimal, not an ideal, rationality to human beings. We have ‘no clear or finished conception of ideal rationality’. Hence, we cannot say that the explanatory failures of FP are due to people failing to live up to its ideals. 3. There is no reason to think that FP is applicable to any sort of cognition other than adult, language-using human beings. To make any advance in cognitive sciences, we need to go beyond FP and give a deeper and more accurate account of cognition. Eliminativism does not imply the rejection of all normative concerns but only that these things will have to be reconsidered at a deeper level- the level of neuroscience. Churchland concludes that FP is nothing but a culturally entrenched theory of how humans and higher animals work. PART 4: Beyond folk psychology Churchland sketches three scenarios of what elimination of FP might look like. First scenario: Connectionist We arrive at a theory of all brains that is consistent with evolutionary biology that ascribes to us at any given moment a complex state that can be described as a solid 4 or 5-Dimensional phase space. Any sentence which is human speaks is like a one-dimensional projection of that multi-dimensional solid. Although this scenario may not have any effect on our ordinary lives, it is not inconceivable that at least some people may start talking about their inner states in the language of the new theory. Second scenario: More radical It starts with the hypothesis that our ability to use language is an additional and acquired function of our apparatus for organizing perceptual experience. Research shows that language lie English utilize only a fraction of our cognitive machinery. The knowledge of how this machinery works allows us to invent much more sophisticated language with a totally new syntax and semantics that makes communication more efficient and FP disappears. Third scenario: We learn about how the two cerebral hemispheres communicate with each other. Based on this knowledge, we invent electronic devices that we can implant in brains that allow brains to communicate with each other without spoken language. Libraries replace books with recordings of neural activity. Given these three scenarios, the elimination of FP is not inconceivable. A final argument against eliminativism: Eliminativism is incoherent because it assumes the very things it wants to eliminate. After all, it’s a belief and one that eliminativists have the desire to communicate and so on. Hence, if eliminativism were true and there were no beliefs and desires, whatever the eliminativist says would then just be a meaningless bunch of noise. Churchland says that this charge begs the question. It assumes that for something to have any meaning, it must express a belief. The argument could be interpreted as showing that it is this theory of meaning that should be rejected. The question-beginning nature of the argument is shown through an analogy he borrows from Patricia Churchland- she says that it would be like a 17th century vitalist arguing that if someone denies they have a vital spirit, they must be dead and hence, not saying anything. This argument begs the question in the same way. Thus, propositional attitudes of FP are not beyond the possibility of being wholly replaced by neuroscience. Philosophy of Mind Study Resource 3 21-Nov-2014