Tag Archives: Hilary Putnam

Hilary Putnam – “Meaning and Reference” Article Summary

Putnam, Hilary ‘Meaning and Reference,’ The Journal of Philosophy 70: 19, (1973): 699-711.



Putnam seeks to undermine two doctrines of standard semantic theory (“theory of meaning,” in a broad sense) via the use of a thought experiment. The doctrines are: one, that intension (‘meaning’, more or less) determines extension (‘reference’, more or less) and in fact is always sufficient for doing so (such that two terms with the same intension must have the same extension); and, two, that intensions are concepts and thus psychological entities (such that two persons in the same psychological state must be grasping the same extension with regards to a term they both use). After presenting his thought experiment, Putnam presents an alternative thesis to explain how groups of speakers utilize intensions if not as psychological entities that fix extension, and argues that his view necessitates that natural kind terms (e.g., ‘water’ or ‘gold’) are rigid designators.

Putnam asks us to consider a world called ‘Twin Earth’ which is exactly similar to Earth – including in the languages spoken, physical properties exhibited by all things, and so forth – except that on Twin Earth, the liquid called ‘water’ isn’t H20, but rather is a molecule with a complicated chemical formula, abbreviated ‘XYZ’. XYZ functions just as H20 does on Earth, occupying the same space and exhibiting all the same physical properties. In other
words, the average resident of either planet would not be able to distinguish H20 from XYZ.

Putnam then modifies the thought experiment such that it becomes a counterexample to the notion that the doctrines can be jointly maintained: Putnam asks us to consider speakers on Earth and Twin Earth that existed before either planet’s scientific communities determined the precise molecular formula for water (on Earth) and ‘water’ (on Twin Earth). Such speakers will stand in the exact same psychological relation to the liquid they call ‘water’ (since the sole dissimilarity between Earth and Twin Earth – the fact that water is H20 and ‘water’ XYZ – is unknown to the speakers), despite the fact that in either instance a different liquid is under consideration. Thus, two persons in the same psychological state nonetheless are grasping a different extension. Yet if both doctrines were true – if intension were always sufficient to determine extension and if intensions were psychological entities – then sameness of psychological state would entail sameness of extension for the term being used. Putnam uses this result to indicate that it is false that intensions are psychological entities.

Putnam presents a further altered version of the thought experiment in order to reinforce the same conclusion about intensions not being psychological: supposing that pots and pans made of aluminum and molybdenum are indistinguishable, that pots and pans are made of aluminum on Earth and molybdenum on Twin Earth, and that on Twin Earth the words ‘aluminum’ and ‘molybdenum’ are switched (such that Twin Earthians refer to what we call aluminum with the word ‘molybdenum’), then speakers from Earth who travel to Twin Earth will be in the same psychological state as the locals with regard to pots and pans, yet will be referring to different things. Thus, sameness of psychological state does not entail sameness of extension; further, intensions are not psychological states: in this instance an Earth speaker and Twin Earth speaker are in the same psychological state yet are using a word to indicate a different meaning.

Putnam presents an alternative vision for how communities of speakers utilize intensions: the use of a word is a communal activity, with a “division of labor” (704) distributing the burden of proper use across a community. In other words, rather than the use of a word depending upon a solipsistic grasping of an intension (which then makes an extension clear) on the part of every speaker of a word, some in the community may simply provide ostensive definitions of words, while others (the scientifically oriented ones) may do the actual work of explicating the extension of terms. The proper determination/utilization of intensions and extensions arises from this communal work, not from the individual psychology of any given speaker.

Putnam then undermines the doctrine that intension necessarily determines extension by launching a discussion of natural kind terms – of which ‘water’ is an example. Putnam thinks that such terms are defined ostensively, i.e., by pointing to a thing in the world as an exemplar of the meaning of the term. To Putnam, to the extent that such terms are defined ostensively, their extension actually determines their intension, in the sense that a paraphrase of the meaning of the term will be of the general form ‘this thing right here,’ perhaps with an accompanying demonstration (e.g., a pointed finger). And the precise meaning of such a paraphrase will be determined by whatever the demonstratum (thing being demonstrated, pointed at) actually is. And this makes it possible for one to not know what is truly ‘meant’ by such a term until a scientific investigation reveals the thing ostended.

Besides undermining the notion that intension always determines extension, Putnam thinks that natural kind terms having as their intension their extension makes it such that these terms are ‘rigid designators’, or terms that refer to the same thing in all possible worlds. This is because a natural kind term is established (“baptized” one might say) via ostension, which relates to the actual world. Thus, such a baptismal rite will go something like, ‘Natural kind term n means this thing in the actual world’, meaning that the way the world is for Putnam as much a contributor in determining reference as is any psychological state on the part of speakers, contrary to standard semantic theory.



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Article Summary: “The Nature of Mental States” by Hilary Putnam


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. (Readers are encouraged to investigate the machine more fully if they want the technical details. The points to understand are that 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.

Putnam first addresses whether the question “Is Pain a brain state?” is meaningful at all. 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 off of a
mirror 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 difference 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.

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 physical-chemical 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 em-
pirical 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 physical-chemical 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.

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 different 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 behaviors 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 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 difficulties (from which it would never recover), and Putnam (as he recognizes) is thus able to recite these difficulties. One is that it seems impossible to identity a behavioral disposition without referencing the concept one is attempting to define. So when the disposition of pain is defined, one must say something to the effect 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, if you wish!) who show no difference in behavior and yet are experiencing different 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 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.

Logical Outline

Primary Argument: Functionalism is preferable to the identity theory and behaviorism as a theory of mental states

1. Either functionalism, the identity theory, or behaviorism is the preferable theory of mental states.*

2. The identity theory is not a preferable theory of mental states.

S1. For the identity theory to be viable, a mental state needs to have
the exact same physical correlate in all organisms which experience that mental state.
S2. Very probably, organisms experience the same mental state with
different physical correlates of the same state.
S3. Therefore, the identity theory is probably not viable. [S1,S2]

3. Behaviorism is not a preferable theory of mental states.

S1. For behaviorism to be viable, one must be able to define mental
state dispositions without referencing the mental state itself, and thus
avoid circularity.

S2. It is not possible to define a mental state disposition without
referencing the mental state in question, and thus avoid circularity.

S3. Therefore, behaviorism is not viable. [S1,S2]

4. Therefore, functionalism is the preferable theory of mental states. [1,2]
5. There exist reasons for adopting functionalism, independent of the problems of the identity theory and behaviorism.

S1. A theory of mental states which enables a robust research pro-
gram is to be preferred.*
S2. Functionalism provides a reasonable commonality to identify
among organisms – functional states.
S3. Functionalism successfully prevents a number of questions from
being asked (questions which can waste researchers time).
S4. Functionalism – through its description of organisms’ functional
profiles plus identifications of mental states with functional states – promises to provide laws of psychology.
S5. Therefore, functionalism enables the most viable research pro-
gram [S2-S4].
S6. Therefore, functionalism is preferrable. [S5,S1]

6. Therefore, functionalism is preferable over the identity theory and over
behaviorism as a theory of mental states, and there are reasons to adopt
it independent of the other theories’ difficulties. [5,6]

*Asterisks denote enthymemes, or ‘suppressed premises.’ All these are are assumptions which must be made in order to make the explicitly stated argument work.


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