Wednesday, April 11, 2012

Clark and Chalmers (1998) "The extended mind"

Clark and Chalmers' "The extended mind" is probably a contemporary classic that has been often quoted but not read by a lazy person like me.

The Extended Mind
Andy Clark and David Chalmers
Vol. 58, No. 1 (Jan., 1998), pp. 7-19
Published by: Oxford University Press
Article Stable URL:

In the paper they advocate active externalism, by which they indicate "the general tendency of human reasoners to lean heavily on environmental supports." (p. 8). They introduce the term "epistemic action" (originally from Kirsh and Magliio. 1994) and suggest that if some actions "alter the world so as to aid and augment cognitive processes such as recognition and search" (p. 8), those actions should be granted some credit.

Epistemic action, we suggest, demands spread of epistemic credit. If, as we confront some task, a part of the world functions as a process which, were it done in the head, we would have no hesitation in recognizing as part of the cognitive process, then that part of the world is (so we claim) part of the cognitive process. (p. 8)

In short, "Cognitive processes ain't (all) in the head!" as they say immediately after the excerpt above.

Active externalism opposes the internal idea of cognition which regards the brain (the cognitive engine) as entirely separated from the rest of the world (including its body). Cognition, at least some aspects of it, takes place in the world. In principle, the brain makes a cognitive system when it is embedded in this world. (We're here reminded of the classical argument by Heidegger of Being-in-the-World (In-der-Welt-sein), Dasein or Geworfenheit)

the human organism is linked with an external entity in a two-way interaction, creating a coupled system that can be seen as a cognitive system in its own right. All the components in the system play an active causal role, and they jointly govern behaviour in the same sort of way that cognition usually does. If we remove the external component the system's behavioural competence will drop, just as it would if we removed part of its brain. Our thesis is that this sort of coupled process counts equally well as a cognitive process, whether or not it is wholly in the head. (pp. 8-9)

Active externalism, or externalism in general, may sound implausible if you identify the cognitive with the conscious, but that folk identification has been denied by neuroscience both empirically and theoretically.

Another objection may come from the argument that "what keeps real cognition processes in the head is the requirement that cognitive processes be portable." (p. 10) . This argument implies that external cognition can be easily decoupled from its necessary cognitive entities in the world and that such cognition does not probably deserve the name of cognition, our mental capacity; The 'mind' must consist of something that is always portable: the brain.

Clark and Chalmers admit that there is something to this objection (p. 10). However, they argue that this portability argument does not undermine active externalism by citing examples of counting on our fingers and of the engineer with a slide rule (well, in the old days, at least) (p. 11). I may add the example of a pianist. A pianist has a great mind, quite different from ours, that enables her play the piano beautifully. However, without the piano, she cannot properly practice or rehearse a piece, let alone play. The piano is certainly not portable, but it constitutes an essential part of her cognition. (I guess the same is true with composers. Probably, they cannot properly compose any piece if they are not allowed to touch any music instruments at all. But I'm not a pianist or a composer. Correct me if I'm wrong.)

Moreover, it is quite plausible that the brain evolved so that it can better exploit the external environment (p. 11) Language, indeed, may be a product of such evolution (pp. 11-12)).

Our individual learning, which happens within a much shorter time span than that of evolution, may also mould our brain in ways that rely on cognitive extensions (including language and computer, for example) that surround us.

Clark and Chalmer state:

Once we recognize that the crucial role of the environment in constraining the evolution and development of cognition, we see that extended cognition is a core cognitive process, not an add-on extra. (p. 12)

But again, there is some reluctance to accept (active) externalism. Some may have a strong opinion that "what is truly mental is internal" (p. 12).

To counter-argue, Clark and Chalmers introduces the case of Inga, an ordinary person, and the case of Otto, who suffers from Alzheimer's disease and has to carry a notebook with him everywhere he goes to recall what he saw or thought. The point of the comparison is whether the term 'cognition' in its non-special sense should apply to the case of Otto. Clark and Chalmers of course believe it does.

The way I see this argument is that the point is more about whether we should regard the brain as a special device of cognition, so different from external cognitive resources that it should be categorized as THE cognitive device on its own.

My idea is that the brain is a device, just like any other external cognitive resources are, but it is special in that it is a self-referential device of cognition. Although it must be embodied and embedded in the world, the brain is the single most important device to produce consciousness (or awareness in the sense of 'primary consciousness' (Edelman) or 'core consciousness'(Damasio)), the arena where we know that we congnize. As our sense of cognition is produced in our consciousness, the brain is not only an important part of cognition itself (in the sense of action) but also the only device of knowing about cognition (second-order cognition). The brain is our only cognitive device whereby we know or feel of our own cognition, and in this sense it is very special.

Of course, other devices such as a calculator may be called self-referential. Its new input refers back to its old input to proceed with the calculation; it is self-referential in the process of calculation. But the self-reference in a calculator is not known or felt by us. We use the result of the self-reference of a calculator (i.e. the result of the calculation) as an important part of our cognition (say, a financial simulation), but we don't know or feel in ourselves the process of the self-reference in a calculator. In contrast, when we cognize mostly on the brain (for example, sitting in a quiet room to philosophize), we not only experience the product of our cognition (eg. a tentative conclusion) but also the process of our cognition (eg. beginning to feel something is wrong with the conclusion).

I may be running a risk of almost equating the brain and the consciousness, but this is not what I mean. The point I'm trying to make is that the brain is special because it is not only portable but also self-referential and that because of the self-reference of the brain, we know that we know (or cognize). This second-order observation is the source of self (Damasio 2000, 2010) No other external cognitive entities produce the sense of self. Only the brain does (when it is embodied and embedded, of course). After all, we retain the distinction between internal and external. Brain is an internal device in our extended cognition and it is special in the sense it enables us know what we know or do. However, that internal device alone cannot constitute our cognition, as we're embodied Being-in-the-world.

One addition, though. I've been using the expression "the brain" and it may sound as if it is a monolith, which it isn't. The brain is huge collections of various regions (that are also huge collections of neurons) which interact with each other in highly complex ways. Although consciousness is the arena where we know our cognition and we feel our agency, it's not that we can pinpoint the permanent place of cognitive agency. Consciousness, the sense of cognitive agency, or free will, emerges in the process of enormous and complex interactions of neurons.

Let's go back to Clark and Chalmers' paper. With the idea of active externalism, they also accept the idea of "socially extended cognition" by which they mean that your mental states are partly constituted by the states of other thinkers. (p. 17) (You only have to remember an example of lively discussion, where a creative idea comes out from the space of the in-betweenness (ie, Nobody doesn't think he alone is the creator and owner of the idea).

In such socially extended cognition, language plays an essential role.

In each of these cases [of socially extended cognition], the major burden of the coupling between agents is carried by language. Without language, we might be much more akin to discrete Cartesian 'inner' minds, in which high-level cognition relies largely on internal resources. But the advent of language has allowed us to spread this burden into the world. Language, thus construed, is not a mirror of our inner states but a complement to them. It serves as a tool whose role is to extended cognition in ways that on-board devices cannot. Indeed, it may be that the intellectual explosion in recent evolutionary time is due as much to this linguistically-enabled extension of cognition as to any independent development in our inner cognitive resources. (p. 18)

The idea of extended cognition may have important implications in the moral and social domains.

It may be, for example, that in some cases interfering with someone's environment will have the same moral significance as interfering with their person. And if the view is taken seriously, certain forms of social activity might be reconceived as less akin to communication and action, and as more akin to thought. In any case, once the hegemony of skin and skull is usurped, we may be able to see ourselves more truly as creatures of the world. (p. 18)

As I said, this paper is considered as a very important paper in cognitive science and philosophy of mind. However, as someone who has read this about 14 years later after its publication with the cultural background of Japan in the East, I do not find the argument particularly amazing or controversial. What is rather surprising is that it caused controversies. For many ordinary Japanese (apart from the ideological modernist in academia!), questioning Cartesianism is much easier than accepting it.

Responding to Kant who claimed that it was a scandal that philosophers could not prove the existence of the external world, Heidegger said in Being and Time that the 'scandal of philosophy' is not that this proof has yet to be given, but that such proofs are expected and attempted again and again (

The 'scandal' of applied linguistics may be not that applied linguists cannot yet give a proof that 'alternative approaches' (including extended cognition) to SLA are strictly scientific (whatever it may mean) but that such proofs are expected and attempted again again.


Damasio (2000) The feeling of what happens. Mariner Books.

Damasio (2010) Self comes to mind. Pantheon.

Kirsh, D. and P. Magilio. (1994) On distinguishing epistemic from pragmatic action. Cognitive Science 18: 513-49.

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