The Nature of Mental States - Putnam PDF

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“The Nature of Mental States” by Hilary Putnam In his paper „The nature of mental states “from 1967 Hilary Putnam proposes an hypothesis regarding mental states. He claims that mental states are functional states of Probabilistic Automatons rather than brain states or behaviour dispositions. Putnam defines his position in the actual philosophical debate, especially the Identity theory, and then defines his hypothesis on grounds of empiricalism. Putnam presents a version of functionalism – a position in the philosophy of mind which says that mental states can be defined in terms of their causal roles – as an empirical hypothesis worthy of investigation, especially in light of what he sees as the problems facing the identity theory of mind and behaviorism. Central to Putnam’s conception are the notions of the Turing Machine and of a Probabilistic Automaton. A Turing Machine is a hypothetical device proposed by Alan Turing which computes various tasks in a deterministic fashion, given certain instructions and given a machine table which specifies how various states of the machine relate to one another and to inputs. The machine computes deterministically, and that it has its behavior entirely produced by input and states which ’react’ to the input in a specific fashion, producing computations and transitioning to other states automatically. A Probabilistic Automaton, meanwhile, is very similar to a Turing Machine, except that the transitions between states produced by input are determined probabilistically rather than with certainty.

Is Pain a brain state Putnam first addresses whether the question “Is Pain a brain state?” is meaningful at all. Putnam defines the question as his key topic, which he mentions as one of the three typical concerns of philosophers of the mind at those days. Putnam starts with two rules of analytical philosophy he finds 'excellent', based on the program of reductive analysis. He makes clear that (1) 'A is B' should follow from the meaning of the terms A and B and (2) that 'being A is being B' can only be informative for reductive reasons. Arguing against Carnap. Putnam clearly divides the terms 'concept' and 'property', so that 'A is B' can be true, but 'the concept of A is the concept of B' does not follow thereof. This is where the first rule considering the meaning of terms holds. Putnam in quick succession defuses the objections to the thesis that the question has merit. One such objection is that pain cannot be a brain state because we can know we are in pain and simultaneously not know that we are in brain state ’S’. But this objection also applies to us knowing that there is heat in the oven: we can know that the oven is hot without knowing that its mean molecular kinetic energy is high, despite the fact that heat just is mean molecular kinetic energy. He further argues that the notion of Pain being a brain state is at least intelligible, if not necessarily true, just as other, successful empirical reductions (e.g., water being reduced to H20) have been intelligible. Two objections remain. The first states that the proposed reduction of Pain (and other mental states) to a brain state cannot be successfully engaged unless both things in the reduction are associated with a spatio-temporal area, and the spatio-temporal area is one and the same for both things. Putnam thinks this is wrongheaded and gives a counterexample: the reflected image of of a mirror f is merely reflected light, despite the fact that the image can at times appear behind the mirror. That is to say, empirical reduction is successful (the image is merely reflected light) despite the two things not sharing a spatio-temporal area.

The last objection states that, at best, brain states can be correlated with mental states, but never said to be equivalent to them. The predictions yielded from saying that the brain state and the mental event are correlated are equivalent to those which are yielded when we say that the state is the mental event, and there is thus no principled way of preferring the one over the other. Putnam agrees with this in a sense, but says that the two different views enable/prevent certain empirical questions from being asked. So there is a meaningful diff erence between the two stances. For example, if we assume that identity obtains, the question “What makes the pain accompany the brain state?” is rendered meaningless. Putnam then points out that after all he still wouldn't decide on the meaningfulness of the statement 'pains are brain states' since the notion 'change of meaning' is ill defined. It served other purposes on philosophy, cruder ones, and is no longer useful. He wants to search the answer by allowing a statement 'pain is A' where 'pain' and 'A' do not have to be synonyms and then test such statements on empirical grounds. At this point, Putnam goes on to present his own hypothesis. He makes clear how his hypothesis is an empirical one, which finds its strategy on plausibility grounds

Putnam’s Model of functionalism- Probabilistic Automaton With objections to the very idea of reduction of mental to physical dealt with, Putnam presents his model of functionalism. The model deploys the concepts detailed above: the Turing Machine and the Probabilistic Automaton. The idea is that mental states are functional roles within a system, where a system is (in the case of humans) a Turing Machine with a probabilistic transfer between various states. Putnam denotes the complete functional profile of a system – a complete account of all states and their probabilistic relations with one another and with sensory input – as the description of the system. Further, the behavior of the system is understandable without knowing how the system is realized. In other words, the mind can be understood perfectly well without understanding the particulars of the physicalchemical brain states which realize the mind’s functions. Putnam admits that his model is vague on the details: the model says nothing, in fact, about how the functional states are to be defined (e.g., what does it take for an organism to be ’in pain’?), nor does it say how exactly the functional states relate to stimuli. Nonetheless, Putnam thinks his model is advantageous over the identity theory of mind because it presents researchers with an empirical research program which is less vague, and easier to carry out, than any research program under the auspices of the identity theory. Putnam then espouses the virtue of his functionalism over the identity theory in more depth, but also its virtues over behaviorism. Putnam thinks his functionalism presents a more tractable research agenda because in the case of the identity theory, there must be a singular physical-chemical structure which is, say, pain. If identity theory is true, then researchers will have to find the exact same physicalchemical structure in all the creatures which feel pain, and not find it in creatures which do not feel pain. Putnam admits that this is possible, but thinks that identifying a functional profile which is a commonality to all the organisms is more reasonable than trying to identify the exact same physical structure in all pain-feeling organisms.

Argument against the brain state theory Putnam extends his previous point to apply to the identity theory’s application to all mental states (and not just pain). Indeed, identity theorists have argued that all mental states are merely brain states. Putnam thinks this is almost certainly false, because in order for all mental states to be brain states, the entire physical-chemical structure of all organisms who experience such mental states will have to be the same. And Putnam thinks that this is most unreasonable: if even a single mental state is found to be experienced in another creature, and that creature has a diff erent physical correlate of the mental state than any other creature, then the identity theory is false. Putnam then advances reasons for his theory. The first is that we identity mental states in creatures in light of their behavior, and the commonality in behavior across organisms suggests a similar functional organization, but not a similar physical-chemical organization. This fact is Prima facie evidence for functionalism. Further, we tend to identity mental states in organisms based upon the behaviours they produce and the transitions into other states which they presage. So, we identity ’thirstiness’ partly by the fact that it tends to produce a certain behavior, which then tends to transition the system to another state, namely, ’not needing liquid anymore.’ And this fact about how we delimit mental states from one another suggests the appropriateness of a functional approach to such states. Putnam says that brain state theorists assume only physical properties and consider nonphysical properties unintelligible. Brain state theory is also said to be incompatible with dualism and mentalism. While brain state theorists are proud of this, Putnam considers it a weakness in the theory, because functional state theory, while it doesn’t assert dualism or mentalism, is not incompatible with them at all. Putnam also claims that brain state theory has to specify a universal species-independant physical-chemical state that leads to the same physical correlate of pain. This is impossible to do. Since the brain state theorist maintains that every psychological state is a brain state, one should not be able to find one state which can be clearly applied to two different species when their physical-chemical state is not the same. But Putnam gives an example of applying ‘hungry’ to both a mammal and an octopus. Their physical-chemical states are entirely different, but they can have the exact same psychological state. Putnam concludes that brain state theory fails because neurophysiological laws haven’t been developed to the point of being species-independent.

Argument against the behavioural disposition theory. Putnam then compares the functional approach to behaviorism, another theory of identifying mental states. In the case of behaviorism, the mental states are defined as a behavior, or disposition to behave, on the part of an organism. Putnam gives a reason for supposing behaviorism is not particularly advantageous: despite the fact that we identify mental states by using behavior, this fact does nothing at all to suggest that the mental state actually is the behavior. At the time the article was written, behaviorism was facing serious conceptual diffi culties (from which it would never recover), and Putnam (as he recognizes) is thus able to recite these diffi culties. One is that it seems impossible to identity a behavioural disposition without referencing the concept one is attempting to define. So when the disposition of pain is defined, one must say something to the eff ect of ’pain is a disposition of X to behave as if X

were in pain.’ In contrast, a functionalist can simply identity a functional state which pain can then be equated to. Further, there can be animals (or persons) who show no difference in behavior and yet are experiencing diff erent mental states. A person X might be in pain and yet be suppressing their pain behavior, whereas a person Y may be in excruciating pain and yet have their motor nerves cut so that they cannot engage in pain behavior. And so pain is not the behavior in either case; it is something else. Putnam claims that behavioural disposition theory defines the state of being in pain using the notion of pain. He seems to be accusing the theory of being circular. The theory does not adequately specify the behaviour. It is very vague. Animals can exhibit the same behaviour when in pain and when not in pain, the correlation between pain and behaviour is not invariable. He also claims that behavioural disposition theory would require a species independent invariant correlation. The theory equates pain with a behaviour disposition without explaining that behaviour, Putnam charges. He says that functional state theory is more plausible, and while that plausibility is subjective, he seems to imply that it is no more subjective than behavioural disposition theory, which is implausible and vague on top of being subjective. The only valid part of behavioural-disposition theory, Putnam maintains, is also part of functional state theory, but functional state theory doesn’t share the problems and difficulties of behavioural disposition theory Methodological justification of functional state hypothesis Putnam concludes by reiterating methodological reasons for accepting a functional approach to mental states: One, the functional approach precludes certain questions from being asked (e.g., “Why does pain always accompany functional state S?”); two, the functional approach actually explains the behavior in question, rather than identifying mere correlations, and third, laws of psychology can be developed once an organism’s description (in Putnam’s sense) is known and a mental state is identified with a functional state. It also explains pain rather than merely correlating it with something else. Finally, functional state theory prevents inquiry from being distracted towards what Putnam considers the “wrong” sorts of questions....