Published online by Cambridge University Press: 08 January 2010
We think that certain of our mental states represent the world around us, and represent it in determinate ways. My perception that there is salt in the pot before me, for example, represents my immediate environment as containing a certain object, a pot, with a certain kind of substance, salt, in it. My belief that salt dissolves in water represents something in the world around me, namely salt, as having a certain observational property, that of dissolving. But what exactly is the relation between such states and the world beyond the surfaces of our skins? Specifically, what exactly is the relation between the contents of those states, and the world beyond our bodies?
1 The term is Pettit's, Philip and McDowell's, John. See their ‘Introduction’ to Subject, Thought, and Context, ed. Pettit, P. and McDowell, J. (Oxford: Oxford University Press, 1986), pp. 1–15Google Scholar.
2 See ‘The Meaning of “Meaning”’, in Mind, Language, and Reality, vol. 2 (Cambridge University Press, 1975), pp. 215–71Google Scholar.
3 See, for example, ‘Individualism and the Mental’, in Midwest Studies in Philosophy 4 (Minneapolis: University of Minnesota Press, 1979), pp. 73–121;Google Scholar, ‘Other Bodies’, in Thought and Object: Essays on Intentionality, ed. Woodfield, A. (Oxford: Oxford University Press, 1982), pp. 97–120Google Scholar, and ‘Individualism and Psychology’, The Philosophical Review 95 (1986), 3–45CrossRefGoogle Scholar
4 See, for example, Burge, , ‘Individualism and Psychology’, Jerry Fodor, ‘Individualism and Supervenience’, Proceedings of the Aristotelian Society, Supplementary Volume 60 (1986), 235–62,Google ScholarPsychosemantics (Cambridge, MA: MIT Press, 1986)Google Scholar, and ‘A Modal Argument for Narrow Content’, Journal of Philosophy 88 (1991)Google Scholar, and McCulloch, Gregory, The Mind and Its World (London: Routledge, 1995)Google Scholar. Many who are externalists with regard to contentful intentional kinds also endorse externalism with regard to individual states or events that fall under, or are of those kinds. Tyler Burge is one notable example; he is what might be called a token externalist as well as a type externalist (see ‘Individualism and the Mental’, and ‘Individualism and Psychology’, note 7). Token externalism is the view that the natures of individual intentional mental events or states are individuation-dependent on factors beyond persons’ bodies. They are so because they are individuated by the contentful types or kinds under which they fall, which themselves are individuation-dependent on factors beyond persons’ bodies. Since to be a mental event is to be an event of a contentful kind, and since contentful kinds are individuation-dependent on factors external to persons’ bodies, mental events are themselves individuation-dependent on factors external to persons’ bodies. Despite this natural association of type with token externalism, it is possible to be a type externalist without embracing token externalism, and vice versa. Both of these possibilities have been argued for, and in my opinion both positions are defensible. In particular, the combination of type externalism and token internalism is defensible. Whether one is a token as well as a type externalist depends on whether one thinks that it is of the essence of any mental event which is of a contentful type that it be of a contentful type. This is not a question about the truth of the claim that, necessarily, each event that has intentional content has intentional content. That claim is obviously and uncontroversially true. It is a question, rather, about the truth of the claim that necessarily, each event that has intentional content necessarily has intentional content. And this claim is not obviously and uncontroversially true. Whether it is true depends on the truth of other views. For instance, it depends on whether non-reductive physicalism is true and contingent. If it is, then token externalism is false, since nonreductive physicalism is committed to the view that the essences of mental events are physical, not mental. It may be true that mental events, qua mental, cannot be individuated independently of the contentful types or kinds under which they fall; but it does not follow that these events cannot be individuated independently of the contentful kinds under which they fall. For that depends on whether these events are essentially mental events. Despite this natural association of type with token externalism, it is possible to be a type externalist without embracing token externalism, and vice versa. Both of these possibilities have been argued for, and in my opinion both positions are defensible. In particular, the combination of type externalism and token internalism is defensible. Whether one is a token as well as a type externalist depends on whether one thinks that it is of the essence of any mental event which is of a contentful type that it be of a contentful type. This is not a question about the truth of the claim that, necessarily, each event that has intentional content has intentional content. That claim is obviously and uncontroversially true. It is a question, rather, about the truth of the claim that necessarily, each event that has intentional content necessarily has intentional content. And this claim is not obviously and uncontroversially true. Whether it is true depends on the truth of other views. For instance, it depends on whether non-reductive physicalism is true and contingent. If it is, then token externalism is false, since nonreductive physicalism is committed to the view that the essences of mental events are physical, not mental. It may be true thatmental events, qua mental, cannot be individuated independently of the contentful types or kinds under which they fall; butit does not follow that these events cannot be individuated independently of the contentful kinds under which they fall. For that depends on whether these events are essentially mental events.
5 McGinn, (Mental Content (Oxford: Oxford University Press, 1989)Google Scholar) is an exception. He distinguishes between what he calls ‘strong’ and ‘weak’ externalism, and argues for the latter and against the former. By ‘strong’ externalism, McGinn means one which takes content-individuation to require the existence, in the environment in which a thinker is situated, of some object or objects external to the thinker's body. McGinn rejects this view, but endorses the weaker externalist view that content-individuation requires the existence, in the world of the thinker, of some object or objects beyond that thinker's body.
This departure from most other externalism means that McGinn is not prepared to rest the truth of falsity of externalism onthe existence of twin earth examples. Thus, he says:
it understates the case to express the upshot of twin earth reflections as inconsistent with methodological solipsism, since those reflections imply strong externalism, not just weak. Such understatement can be misleading if it encourages the idea that the inapplicability of twin earth arguments to certain cases shows that internalism is true in those cases. You can be a weak externalist about a certain kind of content, and so reject methodological solipsism, and yet deny vehemently thata twin earth case can be given for the content at issue: that is in fact my position about certain kinds of content, as will become apparent. (Mental Content, p. 9, n. 13)Google Scholar.
6 See, for example, Davies, Martin, ‘Aims and Claims of Externalist Arguments’, Philosophical Issues 4 (1993), 227–149Google Scholar, where externalist theses are explicitly formulated in these terms. Also, see McLaughlin, Brian and Tye, Michael, ‘Externalism, Twin-Earth, and Self-knowledge’, in Knowing Our Own Minds, ed. Wright, C., Smith, B., and Macdonald, C. (Oxford: Oxford University Press, forthcoming)Google Scholar, note 39, where externalism is formulated in terms of supervenience, and Burge, ‘Individualism and Psychology’, where individualism is formulated in terms of supervenience, externalism being the negation of that thesis.
7 The Putnam twin earth thought experiments concern weak supervenience, since Putnam envisaged twin earth as being a planet in our own universe, and so in the same possible world. Twins are members of different linguistic communities, but communities within the same possible world.
8 See Jackson, Frank, ‘Armchair Metaphysics’, in Philosophy in Mind: The Place of Philosophy in the Study of Mind, ed. Michael, M. and O'Leary-Hawthorne, J. (Dordrecht: Kluwer Academic Publishers, 1994), pp. 23–42CrossRefGoogle Scholar, who characterizes supervenience in similar terms, as lack of independent variation.
9 For example, there are supervenience relations between logically or conceptually related properties, such as being coloured and being red, supervenience relations between what we might call ‘metaphysically’ related properties, such as moral or aesthetic properties and psychological ones, or psychological properties and physical ones, and supervenience relations between causally related properties, such as those that figure in causal laws. All of these conform to the formula that is thought to characterize supervenience relations generally, namely, no change in supervenient property without a change in subvenient property. So no psychological change without a physical change, no aesthetic change without a physical change, no change in effect property without a change in cause property. But the relations are really very different in these different types of cases. Although they all involve a relation between properties, they differ in the types of properties related, and they differ in the kind of relation that is thought to hold between them. Other theses differ from these in relating, not properties, but regions of worlds or worlds themselves, or events or states.
Global supervenience claims typically concern worlds or regions of worlds. See, for example, Horgan, Terence, ‘Supervenience and Microphysics’, Pacific Philosophical Quarterly 63 (1983), 29–43CrossRefGoogle Scholar.
10 See, for example, Martin Davies, ‘Externalism, Architecturalism, and Epistemic Warrant’, in Knowing Our Own Minds, ed. Wright et al., and B. McLaughlin and M. Tye, ‘Externalism, Twin-Earth, and Self-Knowledge’, same volume. The twin earth thought experiments are standardly construed as supporting conceptually necessary externalist theses. This is what lies behind arguments of the kind that Michael McKinsey has advanced to show that externalism is incompatible with privileged access, or authoritative self-knowledge. His argument depends on externalism being committed to the claim that it is a conceptual truth that, for some thought content, C, which has externalistic individuation conditions (such as that water is transparent), it is a conceptual truth that if one is thinking that C, then P, where P is a proposition that cannot be known a priori (such as water exists). See McKinsey, Michael, ‘Anti-individualism and Privileged Access’, Analysis 51 (1991), 9–16CrossRefGoogle Scholar. For a reply which denies that externalism is committed to such a claim, see Brueckner, Anthony, ‘What an Anti-individualist Knows A priori’, Analysis 52 (1992), 111–18CrossRefGoogle Scholar. But many externalist theses do not purport to be conceptually necessary. See, for example, Dretske, Fred, Knowledge and the Flow of Information, (Cambridge: MA: MIT Press, 1980)Google Scholar and Explaining Behaviour: Reasons in a World of Causes (Cambridge, MA: MIT Press, 1988Google Scholar), Millikan, Ruth, Language, Thought and Other Biological Categories (Cambridge, MA: MIT Press, 1984)Google Scholar, Papineau, David, Reality and Representation (Oxford: Basil Blackwell, 1987)Google Scholar, and Fodor, Psychosemantics. There re differences between the view known as anti-individualism and externalism. Fodor, for example, explicitly distinguishes the two, and claims that externalism is true, but anti-individualism is not (see ‘A Modal Argument for Narrow Content’). Externalism is a view about how the contents of intentional states, states with propositional content, are correctly individuated. Anti-individualism, on the other hand, is a view about how the contents of intentional states are, or should be, individuated for the purposes of a scientific psychology, i.e. for the purposes of (causal) explanation in psychology. The distinction between externalism and anti-individualism raises important questions about the nature of psychological explanation and the nature of scientific explanation and taxonomy in general. However, these issues are largely irrelevant to the present discussion, and so the distinction will not play a role in the argument to be developed.
11 McLaughlin and Tye (‘Externalism‘) have pointed out that no type externalist seems actually to have held a view this strong. Brueckner (‘What an Anti-individualist Knows’), in his reply to McKinsey (‘Antiindividualism’) (whose argument is directed at Burge), points out that Burge (in ‘Other Bodies’) actually argues against this view.
12 Burge (‘Other Bodies’) is one. See also Fodor (Psychosemantics), Millikan (Language, Thought, and Other Biological Categories), Papineau (Reality and Representation), and Dretske (Knowledge and the Flow of Information and Explaining Behaviour).
13 The argument is this. Whether a concept is a natural kind concept cannot be known a priori, since it cannot be known a priori that there are natural kinds (and according to at least one version of externalism there can be no natural kind concepts without natural kinds). This can only be known a posteriori, if at all, since whether or not there are natural kinds is an empirical matter. But if it cannot be known a priori that the concept of salt is a natural kind concept because it is not knowable a priori that there are natural kinds, then it cannot be a conceptual truth that if one is thinking that water dissolves in water, then salt exists. See Brueckner, ‘What an Anti-individualist Knows’.
14 I am thinking of Millikan, Language, Thought, and other Biological Categories, Dretske, Knowledge and the Flow of Information and Explaining Behaviour, Jerry Fodor, Psychosemantics, and Papineau, Reality and Representation. It is difficult to know where to place McGinn (Mental Content). On the one hand, he rejects the requirement of causal interaction with instances of the natural kind by individuals who possess concepts of that kind (and in this he commits himself to a thesis weaker than Millikan's and others), and on the other he seems to think that a thinker's thinking such contents conceptually entails that objects exist beyond the bodies of subjects who think them. For more on this, see McLaughlin and Tye, ‘Externalism’.
15 See McDowell, John, ‘On the Sense and Reference of a Proper Name’, Mind 86 (1977)Google Scholar, and Evans, Gareth, ‘Understanding Demonstratives’, in Meaning and Understanding, ed. Parret, H. and Bouveresse, J. (Berlin: W. De Gruyter, 1981), pp. 280–303Google Scholar, and The Varieties of Reference (Oxford: Clarendon Press, 1982), chapters 4–8.Google Scholar
16 See McGinn, , Mental Content.Google Scholar
17 See Putnam, ‘The Meaning of “Meaning”’.
18 See Burge, ‘Individualism and the Mental’.
19 I leave open the issue of whether such variation would entail variation in phenomenological, or ‘felt’ properties. It may be that variation in factors beyond the body of an individual would affect not only contentful states such as beliefs and thoughts, but also sensation states such as perceptual experiences. This is so, for example, for externalists who think that there is no non-conceptual content (see, for example, McDowell, John, Mind and World (Oxford: Oxford University Press, 1995).Google Scholar
20 One might think that dualism alone is sufficient to account for the truth of this claim. However, dualism is silent on the internalism'externalism issue. It is consistent with dualism that mental contents should be individuation-dependent on factors external to the bodies of thinkers (and so external to the mind). See McCulloch, , The Mind and Its World, p. 227Google Scholar, note 5.
21 This is Davies's terminology. See ‘Aims and Claims of Externalist Arguments’, p. 227–8. See also his ‘Externalism, Architecturalism, and Epistemic Warrant’.
22 As Martin Davies puts it, constitutive externalism says that 22 As Martin Davies puts it, constitutive externalism says that the most fundamental philosophical account of what it is for a person or animal to be in the mental states in question does advert to the individual's physical or social environment, and not only to what is going on within the spatial and temporal boundaries of the creature. (‘Aims and Claims of Externalist Arguments’, 230). Davies correctly points out that one can establish a constitutive externalist thesis by establishing that modal individualism is false, i.e. that the supervenience claim (1) stated above is true, but that one cannot establish modal externalism just by establishing that constitutive externalism is true. It may be, for example, that although constitutive externalism is true, modal externalism is false because there is a necessary connection between subjects‘ intrinsic physical properties and factors or conditions beyond that subjects’ bodies, so that an environment in which the contents of subjects‘ intentional states varied would necessarily be an environment in which their intrinsic physical properties also varied.
23 This emerges in debates such as that between Burge and Fodor concerning the truth or falsity of anti-individualism. Burge argues that attention to actual descriptive and explanatory practices in psychology reveals that the taxonomy of both intentional and nonintentionally described behaviour and the taxonomy of intentional states to be non-individualistic. For the interpretation of these practices fails to respect local supervenience, and this is supported by the twin earth thought experiments. However, his arguments for anti-individualism, based on these arguments, have been charged with presuming the truth of anti-individualism. In a similar vein, Burge effectively accuses Fodor's arguments for individualism, which also make use of twin earth thought experiments, of presuming the truth of individualism. Fodor argues that since whether or not twins have type-identical states depends on whether they have the same causal powers, and since sameness and difference of causal powers must be assessed across contexts rather than within them (casual power being a counterfactual notion), whether twins have type-identical intentional states depends on whether their states have the same causal powers across contexts. Burge agrees, but argues that twin earth considerations cannot determine and distinguish causal powers of intentional kinds because one cannot decide which contexts are relevant for determining and distinguishing causal powers without making assumptions about the kinds in question. To suppose that the actual environment external to subjects‘ bodies is not relevant to determining causal powers, and so taxonomy of contentful kinds, is already to assume individualism. The moral for the twin earth thought experiments is that they play a more peripheral role in adjudicating between individualism and anti-individualism. The reason is that their employment is evidently not independent of individualistic/antiindividualistic assumptions. See the debate between Burge, and Fodor, in Philosophy of Psychology: Debates on Psychological Explanation, (ed.)Macdonald, C. and Macdonald, G. (Oxford: Basil Blackwell, 1995), containing Burge’s ‘Individualism and Psychology’ and Fodor's ‘A Modal Argument r Narrow Content’, with a commissioned reply by BurgeGoogle Scholar.
24 In fact, nothing in the argument to follow requires commitment to any doctrine about natural kinds, even though the examples concern what many would consider to be natural kinds. Natural kinds are typically employed in twin earth thought experiments in order to bolster the view that twin earth twins might have thoughts that are distinct despite the phenomenological indistinguishability of the objects or substances to which their thoughts relate in their respective environments. However, the thesis that is being defended here is constitutive externalism, not twin earth externalism. Further, the examples on which the argument is mounted make reference only to the observable effects on normal observers of objects in their environments.
25 See ‘Individualism and Psychology’, and ‘Intentional Properties and Causation’, in Philosophy of Psychology, ed. Macdonald and Macdonald, pp. 226–35.
26 Fodor, ‘A Modal Argument for Narrow Content’. Fodor has since given up his commitment to narrow content. See The Elm and The Expert (Cambridge, MA: MIT Press, 1994)Google Scholar.
27 See Burge, ‘Individualism and Psychology’.
28 Thus he claims, One could plausibly claim that it is a conceptual truth that hearts differ from twin waste-pumps in that they pump blood. One could plausibly claim that it is conceptually necessary that if something is a heart, then when functioning normally, it pumps blood. (‘Intentional Properties and Causation’, p. 233).
29 According to Burge, that is. See ‘Intentional Properties and Causation’. In this Burge concurs with Neander (‘Functions as Selected Effects: The Conceptual Analyst's Defense’, Philosophy of Science 58 (1991), 168–84.). But note that Millikan (Language, Thought, and Other Biological Categories) denies that there are such conceptual connections between functional properties and the effect properties to which their taxonomy is sensitive. Similarly for intentional properties.
30 Two objections might arise here. One is that what is appropriate behaviour towards an object depends in part on how the type of object involved in that type of behaviour is specified, and that, specified more generally (say, as ‘the thirst-quenching, odourless, transparent, colourless liquid’), twater is appropriate for Sue to wash with, because on twin earth, the stuff which satisfies that description gets things clean. The other objection is that appropriate behaviour must be, as the functional behaviour is, capable of allowing for novelty in the range of objects to which such behaviour can become adapted. Creatures move around and may, in new environments, encounter objects of kinds that are distinct from those of the kinds to which their behaviours were initially adapted. It may thus be accidental that these objects serve the needs for which the behaviours were initially selected. Still, engaging with them might prove to be beneficial for these creatures, and so it may be functional for them to behave in the same way towards these new items as they did towards the old ones.
31 In biology, teleology arises from the working of natural selection As Burge puts the point, Imagine that a heart and an organ that pumps digestive waste (from a completely different evolutionary scheme) were physically indistinguishable up to their boundaries. Clearly they would be of two different biological kinds, with different causal powers, on any conception of causal power that would be relevant to biological taxonomy. Judging the heart‘s causal powers presupposes that it is connected to a particular type of bodily environment, with a particular sort of function in thatyy environment. One cannot count being connected to such a body to pump blood as just one of many contexts that the heart might be in, if one wants to understand the range of its biologically relevant causal powers. It would show a serious misconception of biological kinds to argue that the causal powers and taxonomically relevant effects of the heart and its physicyyal twin are the same because if one hooked up the waste pump to the heart’s body, it would pump blood and cause the blood vessels to dilate; and that if one hooked the heart to the waste pump's body, it would move waste. (‘Intentional Causation and Psychology’, p. 227)
32 This is the view of biological-functional kinds advocated by Millikan in numerous works. See particularly Language, Thought, and Other Biological Categories, and White Queen Psychology and Other Essays for Alice. It is a causal-historical (in contrast to a propensity) account of biological function.
33 Millikan uses the term ‘Normal’ (with capital ‘N’) to distinguish the biological-normal from ‘normal’ in the sense of ‘average’ or ‘usual’ or ‘typical’. See Language, Thought, and Other Biological Categories.
34 See, for example, Tyler Burge, ‘Intellectual Norms and the Foundations of Mind‘, Journal of Philosophy 83 (1986), 697–720CrossRefGoogle Scholar.
35 Thus she says,
it is implicit in contemporary ‘externalist’ accounts of the contents of thought that what is consistent versus inconsistent, indeed, I will argue, what is rational versus irrational, is not epistemically given to the intact mind. (‘White Queen Psychology’, in White Queen Psychology and Other Essays for Alice, p. 281)
And similarly,
If the White Queen is right, then that Alice has a coherent system of thought, that she possesses, for example, only one thought of each semantic kind, and hence that she thinks in accordance with laws, say, of rational psychology, depends on a felicitious coordination between Alicethe- organism and Alice‘s environment. It depends, in fact, on much the same kind of felicitous coordination that constitutes Alice’s thinkings of true thoughts; rationality fails to be in the head in the same sort of way as does truth. (Ibid., p. 285.)
The illusion that modes of presentation will help save logical possibility also rests on a failure to see that rationality pivots essentially on referential content, or Bedeutung, and not at all on mode of presentation, that rationality cannot simply be lifted up and attached to mode of presentation. The capacity to reidentify content but only under a mode is a restriction on rationality, a lessening of rationality, not a removal of rationality into an inner and safer sphere. (Ibid., pp. 283–4.)
Millikan apparently thinks that that rationality, like content itself, is world-involving, shows that it lies beyond the subject altogether (‘rationality pivots… not at all on mode of presentation’, ‘rationality fails to be in the head in the same sort of way as does truth’). I deny that content exter-nalism has this consequence. That rationality is world-involving does not thereby show that it does not depend in any way on the perspective of the subject, and so does not show that the norms that govern rationality lie beyond the individual. That what is thought about when thinking a content lies beyond the individual does not show that how it is thought about is not also involved in thinking rationally. The rejection of narrow content does not force one to reject any role for the subject to play in rationality; nor is it a ‘pernicious Cartesianism’ to insist on the importance of that role. Without it, it is difficult to see why subjects should be critically reflective thinkers, and what role critical reflection might serve in an individual's psychology.
36 So I am recommending a combination of metaphysical externalism with regard to the determinants of intentional content and epistemological internalism with regard to the norms that govern rationality. Burge seems to pursue a similar strategy. See ‘Our Entitlement to Self-Knowledge’, Proceedings of the Aristotelian Society 96 (1996), 91–116CrossRefGoogle Scholar.