In the philosophy of mind,externalism is the view that whatis going on in an individual’s mind is not (entirely) determinedby what is going on inside her body, including her brain. Externalismcomes in two principal forms: externalism about mentalcontent and externalism about thevehicles orbearers of thatcontent. The latter form of externalism is commonly known as theextended mind. At stake are important issues concerning the nature of themind and its relation to the world, both natural and social.

• 1. Introduction
• 2. Historical Antecedents
• 3. Content Externalism
  • 3.1 Arguments for Content Externalism
  • 3.2 Responses to Content Externalism
  • 3.3 Narrow Content
• 4. The Significance of Content Externalism
• 5. Extended Mind
  • 5.1 State-Oriented Extended Mind
  • 5.2 Objections to State-Oriented Extended Mind
  • 5.3 Process-Oriented Extended Mind
  • 5.4 The Mark of the Cognitive/Mental
• 6. The Scope of Extended Mind
• 7. Extended Mind and the 4E Mind
• Bibliography
• Academic Tools
• Other Internet Resources
• Related Entries

1. Introduction

In the philosophy of mind,externalism is the view that whatis going on inside an individual’s body does not always, on itsown, fix what is going on inside that individual’s mind. Themind, in this sense, simply denotes the totality of mentaloccurrences undergone by an individual at any given time. Thebody, in this sense, delineates the biological boundaries ofthe individual which, in creatures such as us, coincide with theindividual’s skin and, of course, includes the brain,traditionally taken as the crucial determinant of anindividual’s mental life. Thus, externalism is the view that anindividual’s bodily (including neural) events, states,processes, etc. do not always, on their own, determine the mental,states, processes had or undergone by that individual. The qualifiernot always permits there to be cases—perhapsmany—in which mental occurrences are fixed by bodilyoccurrences. Externalism, generically at least, is merely committed tothe claim that this does notalways happen. The qualifieron its own is intended to convey that even if anindividual’s bodily occurrences do notcompletelydetermine which mental occurrences are had or undergone by thatindividual, the former will at leastpartially determine thelatter and, indeed, can play an important role in such determination.

Externalism appears in two major forms.Content externalismis externalism about mentalcontent—the content ofmental states. It claims that the contents of at least some mentalstates are not solely determined by occurrences falling within thebiological boundaries of that individual that has them. Since mentalstates that have content are typically individuated by that content,this entails that which mental states an individual has is notcompletely determined by occurrences falling within the biologicalboundaries of that individual.Vehicle externalism, more commonly known as the thesis of theextended mind, is externalism about thevehicles of mental content. According to the thesis of extended mind, the vehicles of mental content—roughly, the physical or computational bearers of this content—are not always determined or exhausted by things occurring inside thebiological boundaries of the individual. Content externalism and extended mind are logically independent views, and it is not uncommon to find adherents of one view denying the other. These two forms of externalism diverge sharply not simply because they are externalism about different things—contents and vehicles,respectively—but also because they have differentconceptions of this failure of determination. If mental contents are not determined solely by what is occurring inside the biological boundaries of an individual, this is quite different from the way in which the vehicles of content are not determined solely by what is occurring inside these boundaries. In other words, each form ofexternalism differs not only in what it claims to be external, butalso in what it means by “external”.

2. Historical Antecedents

Externalism—whether of content or vehicle—is often viewedas a peculiar eruption of late twentieth-century analytic philosophy.This, however, is historically myopic. Cognate views with fairly clearexternalist credentials have been advanced and defended much earlierthan this, and in some of the defining works of twentieth-centuryphilosophy (see Rowlands 2003: Chapters 3&4). Wittgenstein (1953)argued that meaning something by a sign does not consist in an innerstate or process. Rather, the possibility of such meaning dependsessentially on the existence of acustom orpracticeof using a sign in given way, and themastery of atechnique—i.e., the ability to adjust one’s use ofthe sign to bring in into accordance with this custom. According tothe dominant—community—interpretation of thenotion of a custom, this entails that the possibility of meaningsomething by a sign is dependent on the existence of a practiceexternal to the individual meaner, and that what this individual meansby a sign on any given occasion depends, at least in part, on thisexternal practice. As we shall see, this social version of contentexternalism was later developed, powerfully, by Burge (1979,1986).

There are earlier views that are, at least, closely aligned withexternalism. Sartre (1943 [1957]) argued that consciousness—histerm for intentional mental acts in general—isnothingin the sense that it exists only as a pure directedness towards theworld, and is essentially dependent for its existence on the objectsto which it is directed. As a consequence, Sartre claimed,consciousness has “no content”. What he meant by this thatwhat we, today, would call the contents of intentional acts arealways, necessarily, outside those acts—transcendent items inthe world rather than immanent things inside consciousness. Contentexternalism seems to be a trivial implication of this. If it werepossible to transplant a consciousness from one world toanother—a staple, as we shall see, of later externalistliterature, but which may or may not make sense on Sartre’sview—the contents of this consciousness would necessarilychange. The reason this may not qualify as externalism in the standardsense, however, is that Sartre also defended a revisionist conceptionof the body. Thebody-as-lived, Sartre argued, is notidentical with thebody-as-object—the way the body isconceived of in the formulation of externalism. Rather, thebody-as-lived is revealing activity whose boundaries in no waycoincide with those of the body-as-object. Thus, rather than being astraightforward form of externalism, Sartre’s view may better beregarded as an abandoning the categories in terms of which the ideasof externalism—and its oppositional counterpart,internalism—are formulated. The same is true of Heidegger (1927[1962]), to whom Sartre’s discussion of the body was heavilyindebted. Heidegger urges us to think of humanreality—dasein, the characteristic type of beingpossessed by humans—not as a biological organism but, rather, asa network of natural and social practices. Humans minds, to the extentthey have any place in this scheme, would certainly not reside inhuman bodies. However—and this is why it does not qualify asexternalism in the usual sense—neither do bodies. (But seeWheeler 2005, for a defense of extended mind grounded inHeidegger’s work.)

Whether or not they can ultimately be characterized as externalist,the views of Wittgenstein, Sartre and Heidegger play an important rolein contextualizing the later development of externalism. Likeexternalism, they all occupy a position that can be labeledanti-Cartesian. They are all opposed to the idea that themental processes had by an individual are always, and completely,determined by what is going on inside that individual’s body (orthey expand the idea of the body in non-Cartesian ways, as in the caseof Sartre and Heidegger). This type of view is not peculiar tophilosophy. In psychology, expressions of the idea can be found in thework of the Soviet psychologists, most notably Vygotsky (1934 [1962]), and Luria and Vygotsky (1930 [1992]) and later in James Gibson’s (1966, 1979) development of anecological psychology (see also Donald 1991 for a more recent development in this tradition). The roots of this anti-Cartesianism are not onlybroad but deep, predating Heidegger, and indeed the twentieth century.Gallagher (2018) argues that versions of this can be found in Americanpragmatism. It may be that the ultimate roots of this sort of anti-Cartesianism lie in Hegel (Crisafi & Gallagher 2010; Boldyrev& Herrmann-Pillath 2013). Whether or not this is correct,externalism—in either form—is best regarded as less an unprecedented eruption, and more as a recent expression of thishistorical tradition of anti-Cartesian thought.

3. Content Externalism

Many mental states or acts (some thinkall mental states oracts) are intentional in that they are about something or other. Youdo not simply think; you thinksomething. You do not merelybelieve or desire; you believe or desire something. This somethingthat you think, believe, desire or, for that matter, hope, fear,expect, anticipate, and so on, is thecontent of thethinking, believing, desiring, hoping, fearing, expecting andanticipating.Content externalism—sometimes known assemantic externalism, since content is sometimes known assemantic content—is externalism about the content of mentalstates or acts.

Content externalism is typically understood as a claim ofdependent possession which is, in turn, grounded in a morebasic claim ofindividuation dependence. The idea ofdependent possession is straightforward: whether or not an individualcan entertain the content thatp (for example, by having abelief, thought, desire or other propositional attitude with thiscontent) depends on the nature of that individual’s environment(and facts about its relation to that environment). It is not possiblefor an individual to entertain this content unless the environmentcontains the requisite objects, properties, facts, events etc. of acertain sort (McGinn 1989). Content externalism is the claim that, atleast in some cases, though not necessarily all, the possession of amental state with a given content is environmentally dependent in thissense.

This claim of dependent possession is derivative upon a further claim:individuation dependence. The general idea of individuationdependence is that the identity of an entity, as an entity of aparticular kinds, depends upon things (objects, properties,facts, etc.) distinct from it. A planet is individuation dependent ona star around which it orbits in the sense that without this star, andresulting orbit, it would not be a planet but some other kind ofcelestial object. The identity of a particular celestial bodyas a planet is dependent on the star and orbit, itemsdistinct from the planet itself. The planet is, in this sense,individuation dependent on the star (Macdonald 1990). A particularskin disturbance correctly classified as sunburn is individuationdependent on solar radiation in the sense that it can be sunburn onlyif it produced by solar radiation (Davidson 1987). Thus, theidentity of a skin disturbance as an instance of sunburndepends on its standing in an appropriate relation to ultravioletradiation, and it cannot be an instance of sunburn unless it stands inthis relation. Sunburn is, in this sense, individuation dependent onsolar radiation

Content externalism is the thesis that at least some mental contentis, similarly, individuation dependent on the nature of theenvironment, understood as a collection of circumstances that resideoutside the biological boundaries of the individual. The identity ofgiven contentp is dependent on circumstances that lie outsidethe biological boundaries of the (objects, properties, facts, events,etc.) of the individual who entertains this content.

3.1 Arguments for Content Externalism

Content externalism is most commonly associated with two vivid thoughtexperiments, presented in the 1970s; the first by Hilary Putnam(1975), and the second by Tyler Burge (1979).

Putnam’s Twin Earth Thought Experiment

Imagine a planet, atwin earth. There are a few things youshould know about this planet. First, it duplicates earth in almostevery respect. On twin earth, at this very moment, a twin version ofyou is reading a twin version of thisStanford Encyclopediaentry, which has been written by a twin version of me. The twinversion of you is your exact, molecule-for-molecule, duplicate.Second, the only difference between earth and twin earth is this: ontwin earth, the substance that sits in oceans, flows in rivers, andcomes out of faucets is not water. It is not water, because it is notmade up of two parts of hydrogen to one part of oxygen. In fact, it isnot made of hydrogen and oxygen at all but, rather, some otherelements entirely absent on our earth. Nevertheless, third, thissubstance looks, tastes, and feels exactly like water does to peopleon our earth, and is used in the same way. Finally, this thoughtexperiment is set in 1750 (and, a corresponding twin 1750), beforepeople had any idea of the underlying molecular structure ofsubstances such as water.

Suppose you say, or write, the sentence, “Water is wet”.Your twin produces a sentence with the same phonetic or syntacticform: “Water is wet”. Do the two sentence-tokens have thesame meaning? Putnam’s answer is that they do not. This answerwill be found inviting by anyone who thinks of meaning as a matter ofreference, ortruth-makers, ortruth-conditions, or, in short, anyone who thinks that themeaning of a term or sentence is, at least in part, a matter of itsrelation to some kind of worldly correlate. Thereference ofthe syntactic/phonetic form “water” differs between youand your twin. When you utter the sentence, you are making a reportabout water—a substance composed of hydrogen and oxygen. Butyour twin’s corresponding report is about the substance on twinearth. For purposes of identification, we can call this substancetwater, but the twin earthlings, of course, call it no suchthing. They speak twin-English, and so refer to this substance withthe syntactic/phonetic form “water”. Moreover, yourutterance and your twin’s utterance are both true, but differentfactsmake them true. Your utterance is made true by a factabout water, whereas your twin’s utterance is made true by afact about twater. Thetruth-conditions of the utterancesalso differ. For your utterance to be true, water must be wet. Foryour twin’s utterances to be true, twater must be wet. Thus,from the perspective of theories that think of meaning in terms ofthese kinds of worldly correlates—reference, truth-makers,truth-conditions—there are good reasons for endorsingPutnam’s conclusion.

As McGinn (1977), and Burge (1979), have pointed out, this claim canbe extended to the content of propositional attitudes. In ascribing apropositional attitude—such as a thought, belief,desire—to a person, we use a “that”-construction,followed by an embedded sentence. The sentence is commonly thought toexpress the content of the propositional attitude: that is, themeaning of the sentence is identical with the content of thepropositional attitude. Therefore, if the sentences expressed by youand your twin have different meanings, it is difficult to avoid theconclusion that the contents of your thoughts, beliefs and desiresalso vary. However, beliefs, and other propositional attitudes areindividuated by their contents. The belief that grass is green is adifferent belief from the belief that snow is white because theircontents are different. Therefore, if the contents of the beliefs hadby you and your twin are different, then so too are your beliefs.

Despite its seemingly outlandish nature, this twin earth thoughtexperiment is just a way of making graphic a simple point. You andyour twin are, as a matter of stipulation, molecule-for-moleculeduplicates. Thus, everything situated inside your head (and biologicalboundaries more generally) is, by stipulation, qualitatively (if notnumerically) identical. Nevertheless, your beliefs (and otherpropositional attitudes) differ. The principle that emerges is, then,this: if you fix what is going inside the head (and biologicalboundaries more generally) of an individual and vary his or herenvironment, some of that individual’s mental states will varywith variations in the environment even though everything in his orher head remains the same. Therefore, what occurs inside the head is,in this sense, not sufficient to determine or fix everything thatoccurs in the mind.

Despite some initially over-exuberant formulations of Putnam(1975)—of the “Cut the pie any way you like, meaning justain’t in the head”, variety—the correct conclusionof this thought experiment does not concern thelocation of(some) mental states but, rather, a claim about theirindividuation. External individuation does not entailexternal location. Sunburn, as Davidson (1987) pointed out, isexternally individuated: individuation dependent on factors that lieoutside the skin. Nevertheless, it is still located on the skin. Thatsome mental states are individuation dependent on circumstances thatexist outside the skin of an individual does not entail that thosemental states are located outside the individual’s skin.

Burge’s “Arthritis” Thought Experiment

Imagine a person, let us call him Larry, who has a number of beliefsabout arthritis. He believes that he has arthritis, that he has had itfor years, that arthritis can be very painful, and that it’sbetter to have arthritis than pancreatic cancer, and so on. He alsobelieves he has arthritis in his thigh. This belief, according toBurge, is (a) an arthritis-belief and (b) false. It is false becausearthritis is an affliction of the joints only. But why is it anarthritis-belief—a belief about arthritis? Burge’s answeris that Larry inhabits a linguistic community made up of people whouse the term “arthritis” in a certain way, and Larry wouldallow himself to be corrected by expert members of that community.Thus, when a doctor tells him, “No, that’s not arthritisyou have. Arthritis is an affliction of the joints”. Larry wouldbe inclined to accept this, and revise his belief accordingly.

Now we imagine Larry in a counterfactual situation. CounterfactualLarry is type-identical with Larry in point of functional profile,behavioral dispositions, and experiential history (allindividualistically specified—that is, specified in such a waythat does not presume the existence of anything outside Larry). Thecounterfactuality of the situation pertains only to Larry’slinguistic community. In this counterfactual situation, the phoneticor syntactic form “arthritis”—as used by physicians,lexicographers, and competent laypersons—applies not only to anaffliction of the joints but also to various other rheumatoidailments. That is, in the counterfactual situation, the correct use ofthe term “arthritis” encompasses Larry’s actualmisuse. In this counterfactual situation, Burge argues, Larrypossesses a true belief about what is going on in his thigh but,crucially, it isnot an arthritis-belief. Rather, he hasbeliefs about a distinct condition—tharthritis, anamalgam of arthritis and rheumatism, as we might regard it.

If this is correct, Larry’s beliefs vary between actual andcounterfactual situations. Larry, however, is identical in bothsituations. The only difference lies in the differing natures of hislinguistic communities—specifically, the differing uses of theword-form, “arthritis”. As in Putnam’sthought-experiment, the difference in meaning again stems from adifference in extension of a term, resulting in differenttruth-conditions, truth-makers, and the like. But in Putnam’scase, the differences stem from differences in the naturalenvironment. In Burge’s thought experiment, these differencesstem from differences in linguistic practice. As in the Putnam case,the argument can easily be extended to the contents of propositionalattitudes, and Burge, unlike Putnam, explicitly endorses thisextension.

3.2 Responses to Content Externalism

Responses to content externalism divide into several kinds. The firsttype of response simply regards externalism as insufficientlysupported by the kinds of arguments developed by Putnam and Burge,either because their conclusions are non sequiturs or because thearguments are deficient in some other way. In this vein, Boghossian(1997), for example, devises the case of “Dry Earth”, aplanet whose inhabitants (who are our intrinsic duplicates) are undertheillusion that there is a clear, colorless liquid flowingout of the faucets and filling the lakes and oceans. According toBoghossian, externalists are committed to implausible claimsconcerning the content of Dry Earthlings’ thoughts about thisillusory liquid. (Segal [2000] endorses a variation on this argumentfrom Dry Earth; see Korman [2006] and Pryor [2007] for externalistreplies.). Crane (1991) argues that in Burge’s example, there isno reason for thinking that Jane has different concepts in the twosituations, as her dispositions remain exactly the same. Crane thinksthat in both situations, Jane lacks the concept of arthritis, butpossesses the concept of tharthritis. Burge was, therefore, mistakenin attributing to Jane in the actual world the belief that she hasarthritis in her thigh. Georgalis (1999) takes a similar view, as doesWikforss (2001).

A second type of response objects to these externalist arguments onbroadly methodological grounds that concern the use of thoughtexperiments, and intuitions more generally, in determining whethercontent is wide or narrow. Cummins (1991) argues that empiricalresearch is needed to find out about the nature of belief, not thoughtexperiments. Chomsky (1995) holds a similar view. The reliance ofPutnam’s and Burge’s arguments on intuitions is anathemato many in the experimental philosophy movement who regard them asculturally-relative and shifting and, therefore, not philosophicallysignificant (see, for example, Mallon et al. 2009).

A third type of response questions the legitimacy of theinternalism-externalism debate. Gertler (2012), for example, hasargued that there is no understanding of the distinction betweeninternal and external properties, and related distinctions such asthat between intrinsic and extrinsic properties, that will correctlycategorize the views we take to be clearly externalist or internalist.If Gertler is correct, perhaps the most common way of understandinginternalism, as the doctrine that content supervenes on the intrinsicproperties of an individual, is unworkable. She therefore maintainsthat there is no genuine dispute at issue in theinternalism-externalism debate, and recommends that philosophers dropthe issue in favor of more well-defined questions. There is, moregenerally, an interesting question concerning how to understand thecrucial distinction between a creature’s external properties andthose that are intrinsic or internal. Many contributors to the debateover externalism take internal properties to bephysicalproperties of a creature that do not depend for their instantiation onany property instantiated outside the boundary of the creature’sbody and brain. A difficulty with this understanding of thedistinction, pointed out by Farkas (2003), is that it appears to ruleout the possibility of antiphysicalist internalists. This is ironic,given that Descartes is often held up as a paradigmatic example of aninternalist about mental content. Williamson (2000) suggests thatinternalism can be understood as the doctrine that mental contentsupervenes on environmentally-independent phenomenal states, andFarkas (2003, 2008) makes a similar proposal.

3.3 Narrow Content

A fourth response to the arguments for content externalism involvesaccepting the force of those arguments but limiting theirsignificance. According to this type of response, externalism is trueof only one type of content, or of content understood in oneparticular way. The kind of content susceptible to Putnam/Burge-styleconsiderations iswide orbroad content. But thereis, some have argued, another type of content—narrowcontent—that is immune to these kinds of arguments. In the yearsimmediately following the publication of Putnam (1975), it was commonto think of narrow content asphenomenal content (see, e.g.,Fodor 1981, 1982; McGinn 1982). The motivation for this is the ideathat even if the contents of you and your twin’s beliefs vary,there is still something that you and your twin have in common. Youboth believe, for example, that the colorless, odorless, transparent,potable etc. liquid in front of you is wet. This strategy faces atleast two problems. First, it conflicts with Burge’s claim thathis type of counterfactual earth argument applies to all conceptsknown by observational means, a category which includes propertiessuch as being colorless, being odorless, etc. Second, even if thefirst objection can be avoided, it is not clear that we can purgethese phenomenal specifications of content of all concepts immune totwin earth style considerations (for example, the concept of liquid asemployed in the above specification) whilst retaining sufficientresources to adequately specify the content of the belief.

Fodor (1987) adopts a different strategy. He agrees that physicallyidentical individuals have different wide contents when embedded indifferent contexts. However, Fodor suggests that their beliefs stillhave the same narrow contents, which are functions from contexts towide contents. You and your twin share this: a something (it isimpossible to specify what this is) which when plugged in to theearthly context yields the (broad) content that water is wet, but whenplugged into the twin-earthly context yields the (broad) content thattwater is wet (a content expressed by the twin-earthly “Water iswet”, of course). This strategy has been objected to byStalnaker (1989) and Block (1991) on the grounds that narrow content,as conceived by Fodor, is not, in fact, content at all. If narrowcontents, as Fodor argues, map contexts of thinking ontotruth-conditions, they do not themselves have truth-conditions andtherefore fail to qualify as contents in any recognizable sense.According to Stalnaker (1989), narrow content is, therefore, nothingmore thansyntax (understood as functional or computationalrole).

There are two more recent developments in semantic theory that canbeen used to identify and defend a concept of narrow content. One ofthese istwo-dimensional semantics and its application to thecontents of propositional attitudes (Lewis 1981, Jackson 2007, andChalmers 2012). Chalmers, for example, argues that a generalized 2Dsemantic framework can be used to isolate an a priori aspect ofmeaning that will be shared by you and your twin. You and your twin,on this view, always have a priori access to the truth-conditions ofyour own thoughts or sentences. If correct, this entails that there isa type or component of content that is not vulnerable to twin earthmanipulation and so might qualify as narrow.

The second development derives from thephenomenal intentionalitytheory. Advocates of the idea of phenomenal intentionality seekto ground the intentionality of mental states in phenomenalconsciousness, the subjective, experiential features of those states.According to this view, phenomenal intentionality is basic, with anyother forms of intentionality derivative upon this basic form (Horgan& Tienson 2002, Loar 2003, Kriegel 2013). According to manyarticulations of the phenomenal intentionality theory (e.g., Siewert1998; Kriegel 2007, 2011; and Farkas 2008), the content of yourthought and that of your twin is the same and that content is narrow.These attempts to construct a viable notion of narrow content havebeen systematically criticized by Yli-Vakkuri and Hawthorne (2018). Ifthey are correct, there is no form of content that can be easilycordoned off from the world, and a thoroughgoing form of contentexternalism must, therefore, be true. (See entry onnarrow mental content for more detailed discussion).

4. The Significance of Content Externalism

The significance of content externalism is potentially far-reachingthough often unclear and disputed.

Idealism. Content externalism is sometimes portrayed as athesis whose truth precludes idealism in at least some of its majorforms (see Rowlands 2003, for example). However, it is not clear thatthis is really the case. For example, even a Berkeleian idealist couldaccept Putnam’s twin earth arguments if thus inclined. All thatis required for Putnam’s argument to work is a distinctionbetween the way water and twater appear and their underlyingstructures. This is something the Berkeleian idealist can, it seems,accommodate. For example, the Berkeleian idealist can explain thedifferences in underlying structure between water and twater in termsof the difference in the ideas that God would flash into your mind andthat of your twin post 1750, when you both get down to the business ofinvestigating (what you think of as) the underlying structure of thesubstance in your oceans and rivers. Content externalism requires areality that exists independently of the thinking subject or subjectsthat feature in the thought experiment. But it does not appear torequire that this reality be non-mental. Some forms of contentexternalism require this, supposition for example Sartre (1943[1957]). But not all forms appear to do so. The relation betweencontent externalism and idealism, in its various forms, is, therefore,not a straightforward one.

Content Externalism and Self-Knowledge. Externalism isimportantly connected with issues surrounding our introspectiveknowledge of our own mental states. Such knowledge appears to beapriori, or at least privileged, in that it is acquired withoutrelying on empirical evidence or observations. On the face of it,externalism threatens the existence of such privileged knowledge. Ifthe contents of our thoughts are determined in part by our relationsto the environment, then one might think that external observationsare needed in order to know what we think. But self-knowledge does notcome about through empirical investigations. So either, contrary toappearance, we do not really know the contents of our own thoughts or,if we do, externalism is false. (See the entry onexternalism and self-knowledge for further discussion).

Externalism and Mind-Body Theories. Externalism has importantconsequences for a number of different mind-body theories. Burge(1979) believes that externalism refutes individualistic theories ofintentional mental states. These are theories that define or explainwhat it is for a person to have an intentional mental state purely interms of intrinsic facts about that person without reference to theenvironment. Examples of such theories include the identity theory,andfunctionalism (see entry) in its traditional guise. McGinn (1989) and Burge (1986, 1993) bothargue that externalism refutes the token-identity theory (and hencethe type-identity theory as well). This is contested by Davidson(1987), Macdonald (1990) Gibbons (1993), and Frances (2007). Withregard to functionalism, one way to deal with externalism is to adopta divide-and-conquer strategy. One might restrict functionalism toproviding an account of what it is to be a particular kind of mentalstate (e.g., a belief) individualistically, while adopting anexternalist theory of content (Fodor 1987). Alternatively, one mightadopt a “long arm” functionalism that specifies functionalroles in such a way that they incorporate worldly items and properties(Block 1990). On such a view, the functional role of your belief thatwater is wet would be different from the functional role of yourtwin’s belief that twater is wet, on the grounds that thefunctional role of your belief involves you perceiving and doingthings with water whereas that of your twin involves her perceivingand doing things with twater.

Though externalism may (or may not) be incompatible with theseinternalist forms of physicalism, this should not be taken to implythat externalism is itself an antiphysicalist doctrine, for one mighthold that although mental contents do not supervene on narrow physicalproperties, they do supervene on wide physical properties. There is noobvious reason for physicalism about the mind to require acreature’s mental properties to supervene on its narrow physicalproperties. (For discussion of the requirements on physicalism, seethe entry onphysicalism.)

Mental Causation. Another debate that arises out ofexternalism concerns the legitimacy of wide contents in causalexplanations. Most philosophers agree with Davidson (1980) thatbeliefs and desires play an important role in the causal explanationof actions. However, it is not clear how this can be reconciled withexternalism. The problem comes up because it has been suggested thatcausal explanations of behavior should appeal only to the intrinsicproperties of our bodies, properties that describe what is happeninghere and now within us (Stich 1983). But externalism says that mentalcontents are determined by causal, social or historical factors,factors which extend spatially and temporally beyond the body. Thisseems to imply that wide mental contents cannot be causally relevantbecause of their relational nature.

There are two main strategies to show that wide mental contents canlegitimately enter into causal explanations. The first strategy is toargue that the causal efficacy of a mental state with wide contentderives from the causal efficacy of a corresponding internal state. Touse a non-mental example, we often say that a mosquito bite causesswelling, even though being a mosquito bite is a relational property.However, one worry with this approach is why it doesn’t showthat wide contents are not causally relevant after all, because it isthe internal component (the skin itching, swollen skin disturbance)that is doing all the causal work. A different way to defend theexplanatory relevance of wide content is to identify its distinctiveexplanatory role without them being parasitic upon the causal efficacyof intrinsic properties. For example, according to Dretske (1988),when my intention to drink water causes me to raise my glass, thebehavior that is the object of the causal explanation is not a singleevent, but a complex process where an internal state causes somebodily movement. Dretske argues that the wide content of my intentionplays a causal role because it provides a structural explanation ofhow the internal brain state comes to be recruited to cause the bodilymovement. Williamson (2000) offers a different account of theexplanatory role of wide contents. He thinks they provide us with abetter understanding of the connection between the mental states of anagent and his actions in the non-immediate future, because our actionstypically involve complex interactions with the environment. (Forfurther discussion, see the entry onmental causation).

5. Extended Mind

The expressionextended mind was coined by Clark and Chalmers (1998), but essentially the same view has gone by a variety of names,including “active externalism”, “extended cognition” (both Clark and Chalmers 1998), “vehicle externalism” (Hurley 1998), “environmentalism” (Rowlands 1999),and “cognitive integration” (Menary 2007). While this variegation in nomenclature is unimportant in itself, it is importantto (a) to distinguish extended mind from other views with which it might be confused, and (b) capture the significant internal variegation in views that might be classified as versions of extended mind. First, however, the general idea needs to be delineated (see Menary 2010 for a collection of thematic papers, both pro and con).

Mental content is not free-floating. Wherever there is mental contentthere is something that has it—avehicle of content.Mentalstates (belief, desires, hopes, and fears, etc.) arenatural candidates for vehicles of content. So too are mentalacts (believing, desiring, hoping, fearing, etc.). As arough, initial approximation,extended mind is the viewthat not all mental states or acts are exclusively located inside theperson who believes, desires, hopes, fears, and so on. Rather, somemental states or acts are, in part,constituted by factors(e.g., structures, processes) that are located outside the biologicalboundaries of the individuals that have them. Thus, extended mind differs from content externalism not merely in being about mental vehicles rather than mental contents, but also in being committed to a claim of external location rather than simply externalindividuation. If extended mind is true, some vehicles ofcontent are not, entirely, located inside the biological boundaries ofindividuals that have them. Rather, they are, partly, constituted by,or are composed of, factors that lie outside those boundaries.

The distinction between states and acts is, in the context of thisform of externalism, a significant one, and the general idea ofextended mind can be developed in two quite different waysdepending on whether we think of the vehicles of content as states oras acts. Thinking of the vehicles of content as states leads to astate-oriented version of extended mind. Thinking ofthese vehicles as acts leads to aprocess-orientedalternative.

5.1 State-Oriented Extended Mind

Clark and Chalmers (1998) provide a canonical argument forstate-oriented extended mind. Otto is in the early stages ofAlzheimer’s, and to facilitate his engagement with the world hewrites down what he suspects will be useful information in a notebook.Reading in a newspaper that there is a particular exhibition going onat theMuseum of Modern Art, Otto looks in his notebook, andfinds the sentence, “The Museum of Modern Art is on53^rd Street”, and, desiring to see the exhibition,duly sets off to 53^rd Street. Clark and Chalmers argue, orare commonly taken to argue, that the sentence should be regarded asone of Otto’s beliefs. Their argument is predicated on afunctionalist conception of beliefs as individuated by theirfunctional roles. The sentence plays a functional role in Otto’spsychological economy that is, if not precisely identical, similarenough to the functional role of a belief in the psychology of anunimpaired subject for the sentence to qualify as a belief. If this iscorrect, it means that at least one of Otto’s beliefs lies inthe notebook rather than in his head. As usually understood, this viewqualifies as a form of state-oriented extended mind to theextent that it identifies a mental state (a belief) with an externalstructure (a sentence).

5.2 Objections to State-Oriented Extended Mind

The identification of a belief with a sentence has provedcontroversial. One objection takes the form of an allegedreductioad absurdum: the identification of a belief with a sentence leadstocognitive bloat (see Ludwig 2015). If the sentences inOtto’s notebook can qualify as his beliefs, why not thesentences in an encyclopedia or the sentences found on theinternet—both of which Otto might also access with relativeease? Clark and Chalmers responded to this worry via two stipulations:(1) the subject must, at some time, have consciously endorsed thisinformation, and (2) the subject must have entered the information inthe book him- or herself. It is unclear whether these will work.Subliminal beliefs provide a problem for the first stipulation, forthese are beliefs that have not been consciously endorsed by theirpossessors. If such beliefs exist, then conscious endorsement of abelief does not seem to be a necessary condition of its possession.With regard to the second stipulation, it is not clear if this iscompatible with Clark and Chalmers’s underlying functionalism.According to functionalism, roughly, if something functions as beliefthen it is a belief. From a functionalist perspective, how a beliefcame to be acquired—entered into a person’s collection ofbeliefs—is not directly relevant. It would be relevant only ifit could be shown that having personally entered the belief intoone’s collection of beliefs it essential to it having thefunctional role of a belief. It is not clear what such an argumentwould look like.

Another objection to state-oriented extended mind is that itconfuses the claim that vehicles of cognition are extended with the(weaker) claim that they areembedded orscaffoldedor, equivalently, that it falls victim to acoupling-constitution confusion (Adams & Aizawa 2001,2008; Rupert 2004). On the state-oriented interpretation, a vehicle ofcontent is extended if it isidentical with, or constitutedby, a structure that lies outside the biological boundaries of anindividual. But a vehicle of cognition is (merely)embeddedif it depends on, or is coupled with (causally or otherwise)structures that lie outside the biological boundaries of theindividual without being identical with those structures. According tothis second objection, arguments for extended mind onlyestablish that vehicles of content are embedded, or coupled, with theenvironment rather than being extended or constituted, by theenvironment.

A third type of objection to state-oriented extended mind is theoriginal intentionality objection, versions of which havebeen leveled by Adams and Aizawa (2001, 2008), Fodor (2009), andRowlands (2010). In a tradition instigated by Brentano, originalintentionality is often taken to be the hallmark of the mental.Original intentionality is defined as intentionality that is notderived. And derived intentionality is intentionality that derivesfrom the mental activity, often mediated by social conventions, of asubject. The intentionality of the sentence, “The Museum ofModern Art is on 53^rd Street”, is clearly derivedintentionality. In itself, this sentence is merely a pattern of shapesagainst a contrastive background and, in principle, could meananything. To mean something, it must be interpreted, and itsintentionality is, therefore, derived. Beliefs are mental entities. Iforiginal intentionality is the hallmark of the mental, then thesentence in Otto’s notebook is not mental. Therefore, theobjection runs, it is difficult to see how it could be a belief.

5.3 Process-Oriented Extended Mind

State-oriented extended mind identifies a mental state (e.g., abelief) with an external structure (e.g., a sentence). However, mentalstates are not the only candidates for the vehicles of content. Mentalacts—thinking, believing (or judging), remembering,etc.—have at least as much claim to be regarded as suchvehicles. And switching the focus from states to acts affords thepossibility of a more process-oriented interpretation of extended mind. We might regard Otto’s notebook as an item of scaffolding in roughly the sense championed by Vygotsky (1934 [1962]). In these terms, the state-oriented version of extended mind identifies a mental state with a piece of this scaffolding—if this piece plays the requisite functional role. In the process-oriented version of extended mind, focus switches from the scaffolding to the process of manipulating the scaffolding. This manipulating of the scaffolding can, on the process-oriented version of extended mind, form part of a cognitive process.

The process-oriented version of extended mind would interpretthe case of Otto rather differently. There is no identification of amental state with an external structure—a belief with asentence. Rather, there is, first of all, a mental process. Describingthis as a process of believing is, perhaps, a little forced: a processof remembering seems more apt. When Otto engages with, ormanipulates, his notebook—flipping through the pages,and scanning each page—this manipulation forms part of hisprocess of remembering the location of the Museum of Modern Art. Thisis only part of the process, of course: little remembering would getdone without a suitable contribution from the brain. Nevertheless,Otto’s manipulation of the book is part of that process.

Two distinct types of motivation can be identified for this claim. Thefirst is a broadly functionalist one, akin to the functionalistmotivation for state-oriented extended mind. The idea is thatthe computational profile of the process of manipulating the book isbroadly similar to that of internal processes responsible forcognition (Wilson 1994, 2004; Clark 1989, 1997, 2008a, 2008b; Rowlands 1999, 2010, Wheeler2010). Standard accounts of cognition postulate information-bearing structures (roughly, representations) and transformative processes performed on those structures, where these processes have the function of identifying information and making it available either to the cognitive subject or to further processing operations. Thus, for example, David Marr’s canonical account of vision postulates a series of information-bearing structures—retinal image, raw primal sketch, full primal sketch, and so on, combined with operations that successively transform one structure into the next. The overall function of these processes is to identify and make available to the subject information that can be used to solve the task of seeing an object. Similarly, when Otto manipulates his notebook this, in general terms, is also what he seems to be doing: acting on information-bearing structures with a view to making available information that he needs to solve the cognitive task of remembering the location of The Museum of Modern Art. From this suitably abstract computational perspective, it is argued, there does not seem to be a huge amount of difference between internal processes performed by the brain on information-bearing structures and external processes performed by the organism on information-bearing structures. They havethe same abstract computational profile and purpose.

Another type of argument draws its inspiration from thephenomenological tradition. Wheeler (2005), for example, draws on thework of Heidegger (1927 [1962]) in defending a version of extended mind. Rowlands (2010), developing certain themes implicit inHusserl and Sartre, defends a model of intentionality asrevealingactivity: the presenting (revealing or disclosing) of an objectas falling under a given mode of presentation. While the activitythrough which this presentation occurs can be purelyinternal—i.e., neural or neurocomputational activity—itneed not be, and typically is not. Often this internal activity iscombined with actions performed by an organism on the world around it.On this view, when Otto manipulates his book, he is engaging inrevealing activity: The Museum of Modern Art is revealed, disclosed orpresented as being located on East 53^rd Street. Thisrevealing activity comprises both activity occurring in Otto’sbrain and wider activity performed by Otto on the world. As revealingactivity, therefore, the process of remembering occurs partly insideOtto and partly outside him.

Whether computationally or phenomenologically inspired,process-oriented extended mindmay fare better withthe objections that were leveled at its state-oriented counterpart.The bloat objection seems to have less purchase on process-orientedextended mind. For example, Otto’s act of rememberingextends no further than the things he does to and with his notebook.There is no reason for thinking that it extends into things such anencyclopedia or the internet that Otto is not currently manipulatingor exploiting.

The original intentionality objection is also, at least partly,deflected. In this amalgamated process, that combines things going onboth inside and outside Otto’s skin, there is originalintentionality aplenty. Otto has to read what he scans on each page,and his seeing will have original intentionality. He will have tounderstand what he sees, and this understanding will also haveoriginal intentionality. Therefore, the overall process is not at alldevoid of original intentionality (Menary 2006, 2007). It can,however, can be objected that this original intentionality is confinedto segments of the process that are located exclusively insideOtto’s skin (Adams 2010). A response to this objection mighttake two forms. One is to accept the claim, and argue that it does notmatter. In this vein, one might point to that the fact that it wouldbe extremely implausible to require that every internal part of acognitive process, understood neuro-physiologically orcomputationally, must possess original intentionality. A retinalimage, for example, might possess original intentionality of a sort.The visual representation into which this image is progressivelytransformed by constructive operations on the part of the brain would,probably, possess original intentionality. But those constructiveoperations would not (Rowlands 2010). The other option is to deny theclaim. This would require showing that at least some things that arenot located in or at the skin possess original intentionality.Rowlands (2006), for example, argues that this is true of what hecallspre-intentional actions ordoings. The debateis ongoing, and it is not clear whether there is an answer that wouldconvince both parties.

5.4 The Mark of the Cognitive/Mental

Tied to this lack of definitiveness is the third charge leveledagainst extended mind: the coupling-constitution confusion. Asimple charge of confusion is difficult to sustain. Proponents ofextended mind are, in general well aware of the distinctionbetween causal coupling and constitution. In the case of Otto, forexample, Clark and Chalmers argue that a sentence should be identifiedwith a belief—rather than the latter being merely coupled withthe former—precisely because the sentence has the functionalrole of a belief. A more plausible form of the objection might be thatthe arguments provided by proponents of extended mind—whether state- or process-oriented—do notestablish what these proponents have taken them toestablish. Specifically, they do not establish anything more than theclaim that cognitive processes are coupled with external processesrather than that they are constituted by them. Answering both theoriginal intentionality objection and the coupling-constitutionobjection, therefore, seems to require the ability to identity when aprocess is, and is not, a cognitive process.

Rupert (2009) argues that the best way to approach this is through theidentification of a cognitive system, an identification that will restheavily on how the sciences of the mind individuate such systems. Themost plausible conception of a cognitive system, he argues, countsagainst extended mind. Another approach argues the need foridentification of amark of the cognitive—a set ofnecessary, sufficient, or necessary and sufficient, conditions for aprocess to count as cognitive. Reaction to this suggestion can bedivided into three broad camps. First, there are those who think thata mark of the cognitive is not necessary. Just as we can study biologywithout a mark of the biological, and practice medicine without acriterion of the medical, we can also do cognitive science without acriterion of the cognitive (Allen 2017). Second, there are those whothink a criterion of cognition is required, can be identified, andcounts against extended mind (Adams 2010). Third, there arethose who think a criterion of the cognitive is available and itsupports extended mind (Rowlands 2009, 2010).

6. The Scope of Extended Mind

In its earlier incarnations, the scope of extended mind wasrelatively restricted, it being understood, primarily, as a thesisabout cognition. The types of external structure or activity involvedin developing the idea of extended mind reflected this focus oncognition. They were predominantly thought of as structures thatcarried information pertinent to the solution of cognitive tasks thatan organism might face, where the organism, through acting on thesestructures, could transform this information from information merelypresent in the structures to information that is available to theorganism (Rowlands 2010). Accordingly, expansion in the scope ofextended mind can, and has, occurred along two (related)dimensions: (1) expansion in scope from cognition to other kinds ofmental process, and (2) expansion in the types of external structureinvolve in these extended mental processes.

Some prominent advocates of extended cognitive states or processeshave been skeptical of the idea that consciousness could be extended,often on the grounds that external structures do not possess the kindof informational bandwidth necessary to sustain conscious experience(Clark 2009, Chalmers 2019). Others are more sanguine about thispossibility, and extended accounts of experiences (Rowlands 2010) andother conscious states, such as emotions (Krueger 2014; Krueger &Szanto 2016; Carter et al. 2016) have been defended. At the same time,and relatedly, there has been an expansion in the types of externalstructures thought relevant. In particular, there has been apronouncedsocial turn in extended mind in recentyears, exploring the ways in which social structures and institutionsmight also, in part, be constitutive of constitute mental processes(De Jaegher et al. 2010, Gallagher 2013, Lyre 2018, and Slors 2019),and the idea that our basic biological cognitive faculties may betransformed by a process ofenculturation (Menary 2015) hashelped reshape extended mind in recent years. One importantexample of this social turn pertains to the study of memory, inparticular, in the way in which memory is oftentransactive—involving the combined efforts of two ormore people, bonded together as a coupled system (Barnier et al 2008; Sutton 2008, 2010, 2015).

7. Extended Mind and the 4E Mind

Another way of delineating the scope of extended mind is by moreprecisely identifying its location in an array of anti-Cartesianpossibilities. Extended mind supplies one of the“E”s in what has become known as4E cognition, orthe4E mind more generally in deference to the idea that itsscope may be broader than simply cognition (Newen, De Bruin, &Gallagher 2018). The label “4E” is intended to capture theidea that at least some mental processes areembodied,embedded,enacted and/orextended, or somecombination thereof.

The clam that mental processes areembodied can mean at leasttwo distinct things (Prinz 2009). On the one hand, it can signify thatmental processes depend on possession and use of a body rather thanmerely a brain (Haugeland 1993, Shapiro 2004). This idea can, itself,fragment into different views, depending on how we understand the ideaof dependence. The claim can be understood as causal dependence:(some) mental processes causally depend (for their existence,identity, etc.) on the body and its characteristics. On the otherhand, it can be understood as a claim ofconstitution: (some)processes occurring inside the body, but outside the brain, canpartially constitute mental processes. On the other hand, there isanother way of understanding the claim that mental processes areembodied, specifically, as the claim that (some) mental processesdepend on mental representations that relate to body (Prinz 2009).These representations come in two forms: ones that affect the body,such as motor commands, and ones that represent or respond to thebody, such as a perception of a bodily movement. Thus, on this view, amental process would count as embodied if it involves, for example, arepresentation located in the motor cortex, even though the motorcortex is intracranial.

Some proponents of extended mind regard their view asantithetical to the claim that mental processes are embodied. Forexample, Clark (2008a) argues that there is, at the very least, a tension between the two views. His version of extended mind is grounded in a liberal version offunctionalism, according to which mental states and processes are individuated by functional roles specified in a fairly abstract way, as general principles linking perception, mental states and processes, and action that does not specify, in any depth, the nature of the mechanisms responsible for this linkage. The claim of embodiment, onthe other hand, Clark sees as grounded either in a rejection of functionalism, or in a form of functionalism that is far more chauvinistic, in that it does, in its specification of functional roles, specify at least some of the details of their realizing mechanisms. Others see extended and embodied views of the mind as much more compatible or aligned than this, even as different facets of the same view (for example, Menary 2007, Rowlands 2010).

A mental process isembedded if it functions, perhaps hasbeen designed to function, in tandem with a surrounding, environmentalscaffolding, such that without the presence of this scaffolding theprocess will fail to do what it is supposed to do, or be less likelyto achieve what it is supposed to achieve, or do what it is supposedto so in a less than maximally efficient way, etc. The externalscaffolding carries information pertinent to the cognitive task thatthe process is designed to accomplish, and a cognizing organism can,by manipulating or exploiting the structure in an appropriate way,avail itself of this information. Cognition, on this view, stillresides in the head. But the net result is that at least some of thedifficulty of the cognitive task is offloaded onto the world. Therequired internal, intra-cranial, processing is not as sophisticatedas it would have needed to be if there was no environmentalscaffolding around. Think of the difference between doing longdivision in your head or doing it with a pen and paper (Rumelhart etal. 1986). The external notation is a form of scaffolding that reducesthe complexity of the required internal processing. Kirsh and Maglio(1994) label this kind of action—that changes the nature of thecognitive task that must be performed internally—epistemicaction.

The claim that some mental processes are embedded is, prima facie, onethat belongs on a spectrum of anti-Cartesian ways of conceptualizingthe mind. A, perhaps, curious feature of the recent dialectic, however, isthat the idea of embedding is often used as a way of devaluing theclaims of extended mind. The idea, here, is that the argumentspurported to establish that mental processes are extended really onlyshow that such processes are embedded (Adams & Aizawa 2008, Rupert2004). This objection is a version of thecoupling-constitution objection outlined insection 5.2.

A mental process isenacted if it involves, or is constitutedby, a dynamic, interactive coupling of processes occurring inside theskin or skull of an organism and processes external to said skin orskull. Enactivism appears in a variety of forms. However, it isplausible to suppose that process-oriented extended mindcoincides with at least some of them. In explaining the nature ofconscious experience, for example, many forms of enactivism appeal tothe ability of the experiencing organism to act on the world around.Abilities, perhaps, need not be extended. But some versions ofenactivism also appeal to theexercise of these abilities. Acommon enactivist way of explaining the sense of phenomenalpresence—the sense of being presented with a richly structured,detailed world—does not appeal to a representational structurethat replicates this detail. If representations area involved at all,they give us merely the rough gist of the visual situation. The senseof richness and details results from the experiencing organismavailing itself of the richness and detail in the world itself(O’Regan & Noë 2001, Noë [ed.] 2002, Noë2004). By acting on a rich and detailed world, therefore, the organisminjects richness and detail into its experience. The organism’sexperience of the richness and detail of the world is realized not bya representation but by a sequence of dynamic, coupled interactionswith the external scene itself.

Enactivism comes in a variety of forms (Chemero 2009; Hutto & Myin2012, 2017; Noë 2004). But an emphasis on dynamic, tightlycoupled interactions between organism runs through all versions ofenactivism and finds clear echoes in at least the process-orientedversion of extended mind. Thus, while there are, perhaps,differences of emphasis, it is likely that some versions of enactivismcoincide with some versions of extended mind.

Bibliography

• Adams, Frederick, 2010, “Why We Still Need a Mark of theCognitive”,Cognitive Systems Research, 11(4):324–331. doi:10.1016/j.cogsys.2010.03.001
• Adams, Fred and Ken Aizawa, 2001, “The Bounds ofCognition”,Philosophical Psychology, 14(1):43–64. doi:10.1080/09515080120033571
• –––, 2008,The Bounds of Cognition, NewYork: Wiley-Blackwell.
• Allen, Colin, 2017, “On (Not) Defining Cognition”,Synthese, 194(11): 4233–4249.doi:10.1007/s11229-017-1454-4
• Barnier, Amanda J., John Sutton, Celia B. Harris, and Robert A.Wilson, 2008, “A Conceptual and Empirical Framework for theSocial Distribution of Cognition: The Case of Memory”,Cognitive Systems Research, 9(1–2): 33–51.doi:10.1016/j.cogsys.2007.07.002
• Block, Ned, 1990, “Inverted Earth”, inPhilosophical Perspectives 4, James Tomberlin (ed.),Atascadero, CA: Ridgeview Press, 52–79.
• –––, 1991, “What Narrow Content isNot”, inMeaning and Mind: Fodor and His Critics, BarryLoewer and Georges Rey (eds.), Oxford: Blackwell Publishers,33–64.
• Boghossian, Paul A., 1997, “What the Externalist Can Know APriori”,Proceedings of the Aristotelian Society,97(2): 161–175. doi:10.1111/1467-9264.00011
• Boldyrev, Ivan A. and Carsten Herrmann-Pillath, 2013,“Hegel’s ‘Objective Spirit’, Extended Mind,and the Institutional Nature of Economic Action”,Mind &Society, 12(2): 177–202. doi:10.1007/s11299-012-0111-3
• Burge, Tyler, 1979, “Individualism and the Mental”,Midwest Studies in Philosophy, 4: 73–121.doi:10.1111/j.1475-4975.1979.tb00374.x
• –––, 1986, “Individualism andPsychology”,The Philosophical Review, 95(1):3–45. doi:10.2307/2185131
• –––, 1993, “Mind-Body Causation andExplanatory Practice”, inMental Causation, John Heiland Alfred R. Mele (eds.) Oxford: Clarendon Press, pp.97–120.
• Carter, J. Adam, Emma C. Gordon, and S. Orestis Palermos, 2016,“Extended Emotion”,Philosophical Psychology,29(2): 198–217. doi:10.1080/09515089.2015.1063596
• Chalmers, David, 2012,Constructing the World, Oxford:Oxford University Press.
• –––, 2019, “Extended Cognition andExtended Consciousness”, inAndy Clark and his Critics,Matteo Colombo, Elizabeth Irvine, and Mog Stapleton (eds.), Oxford:Oxford University Press, Chapter 1.
• Chemero, Anthony, 2009,Radical Embodied CognitiveScience, Cambridge, MA: MIT Press.
• Chomsky, Noam, 1995, “Language and Nature”,Mind, 104(413): 1–61. doi:10.1093/mind/104.413.1
• Clark, Andy, 1989,Microcognition: Philosophy, CognitiveScience and Parallel Distributed Processing, Cambridge, MA: MITPress.
• –––, 1997,Being There: Putting Brain, Bodyand World Back Together Again, Cambridge, MA: MIT Press.
• –––, 2008a, “Pressing the Flesh: A Tensionin the Study of the Embodied, Embedded Mind?”,Philosophyand Phenomenological Research, 76(1): 37–59.doi:10.1111/j.1933-1592.2007.00114.x
• –––, 2008b,Supersizing the Mind:Embodiment, Action, and Cognitive Extension, Oxford: OxfordUniversity Press. doi:10.1093/acprof:oso/9780195333213.001.0001
• –––, 2009, “Spreading the Joy? Why theMachinery of Consciousness Is (Probably) Still in the Head”,Mind, 118(472): 963–993. doi:10.1093/mind/fzp110
• Clark, Andy and David Chalmers, 1998, “The ExtendedMind”,Analysis, 58(1): 7–19.doi:10.1093/analys/58.1.7
• Crane, Tim, 1991, “All The Difference in the World”,The Philosophical Quarterly, 41(162): 1–25.doi:10.2307/2219783
• Crisafi, Anthony and Shaun Gallagher, 2010, “Hegel and theExtended Mind”,AI & Society, 25(1): 123–129.doi:10.1007/s00146-009-0239-9
• Cummins, Robert, 1991, “Methodological Reflections onBelief”, inMind and Common Sense, Radu Bogan (ed.),Cambridge: Cambridge University Press, pp. 53–70.
• Davidson, Donald, 1980, “Actions, Reasons and Causes”,in hisEssays On Actions and Events, Oxford: OxfordUniversity Press, pp. 3–20.
• –––, 1987, “Knowing One’s OwnMind”,Proceedings and Addresses of the AmericanPhilosophical Association, 60(3): 441–458.doi:10.2307/3131782
• De Jaegher, Hanne, Ezequiel Di Paolo, and Shaun Gallagher, 2010,“Can Social Interaction Constitute Social Cognition?”,Trends in Cognitive Sciences, 14(10): 441–447.doi:10.1016/j.tics.2010.06.009
• Donald, Merlin, 1991,Origins of the Modern Mind; Three Stagesin the Evolution of Culture and Cognition, Cambridge, MA: HarvardUniversity Press.
• Dretske, Fred, 1988,Explaining Behavior: Reasons in a Worldof Causes, Cambridge, MA: MIT Press.
• Farkas, Katalin, 2003, “What Is Externalism?”,Philosophical Studies, 112(3): 187–208.doi:10.1023/A:1023002625641
• –––, 2008,The Subject’s Point ofView, Oxford: Oxford University Press.doi:10.1093/acprof:oso/9780199230327.001.0001
• Fodor, Jerry A., 1981, “Methodological Solipsism Consideredas a Research Strategy in Cognitive Science”, in hisRePresentations: Philosophical Essays on the Foundations ofCognitive Science, Cambridge MA: MIT Press, 225–256.
• –––, 1982, “Cognitive Science and theTwin-Earth Problem.”,Notre Dame Journal of FormalLogic, 23(2): 98–118. doi:10.1305/ndjfl/1093883623
• –––, 1987,Psychosemantics: The Problem ofMeaning in the Philosophy of Mind, Cambridge, MA: MIT Press.
• –––, 2009, “Where is my mind?”London Review of Books, 31(3): 13–15.
• Frances, Bryan, 2007, “Externalism, Physicalism, Statues,and Hunks”,Philosophical Studies, 133(2):199–232. doi:10.1007/s11098-005-8446-9
• Gallagher, Shaun, 2013, “The Socially Extended Mind”,Cognitive Systems Research, 25–26: 4–12.doi:10.1016/j.cogsys.2013.03.008
• –––, 2018,Enactivist Interventions:Rethinking the Mind, New York: Oxford University Press.doi:10.1093/oso/9780198794325.001.0001
• Georgalis, Nicholas, 1999, “Rethinking Burge’s ThoughtExperiment”,Synthese, 118(2): 145–164.doi:10.1023/A:1017145322572
• Gertler, Brie, 2012, “Understanding theInternalism-Externalism Debate: What Is the Boundary of theThinker?”,Philosophical Perspectives, 26(1):51–75. doi:10.1111/phpe.12001
• Gibbons, John, 1993, “Identity without Supervenience”,Philosophical Studies, 70(1): 59–79.doi:10.1007/BF00989662
• Gibson, James, 1966,The Senses Considered as PerceptualSystems, Boston: Houghton-Mifflin.
• –––, 1979,The Ecological Approach to VisualPerception, Boston: Houghton-Mifflin.
• Haugeland, John, 1993, “Mind embodied and embedded”,in Yu-Houng H. Houng & J. Ho (eds.),Mind and Cognition: 1993International Symposium, Academica Sinica. pp.233–267.
• Heidegger, Martin, 1927 [1962],Being and Time, J.Macquarie (trans.), Oxford: Blackwell.
• Horgan, Terence and John Tienson, 2002, “The Intentionalityof Phenomenology and the Phenomenology of Intentionality”, inPhilosophy of Mind: Classical and Contemporary Readings,David Chalmers (ed.), Oxford: Oxford University Press, Chapter 49.
• Hurley, Susan, 1998,Consciousness in Action, Cambridge,MA: Harvard University Press.
• Hutto, Daniel and Erik Myin, 2012,RadicalizingEnactivism, Cambridge, MA: MIT Press.
• –––, 2017,Evolving Enactivism,Cambridge, MA: MIT Press.
• Jackson, Frank, 2007, “Reference and Description from theDescriptivists’ Corner”,Philosophical Books,48(1): 17–26. doi:10.1111/j.1468-0149.2007.00426.x
• Kirsh, David and Paul Maglio, 1994, “On DistinguishingEpistemic from Pragmatic Action”,Cognitive Science,18(4): 513–549. doi:10.1207/s15516709cog1804_1
• Korman, Daniel Z., 2006, “What Externalists Should Say AboutDry Earth”,Journal of Philosophy, 103(10):503–520. doi:10.5840/jphil20061031030
• Kriegel, Uriah, 2007, “Intentional Inexistence andPhenomenal Intentionality”,Philosophical Perspectives,21(1): 307–340. doi:10.1111/j.1520-8583.2007.00129.x
• –––, 2011,The Sources ofIntentionality, Oxford: Oxford University Press.doi:10.1093/acprof:oso/9780199742974.001.0001
• –––, 2013, “Phenomenal Intentionality Pastand Present: Introductory”,Phenomenology and the CognitiveSciences, 12(3): 437–444.doi:10.1007/s11097-013-9308-0
• Krueger, Joel, 2014, “Varieties of Extended Emotions”,Phenomenology and the Cognitive Sciences, 13(4):533–555. doi:10.1007/s11097-014-9363-1
• Krueger, Joel and Thomas Szanto, 2016, “ExtendedEmotions”,Philosophy Compass, 11(12): 863–878.doi:10.1111/phc3.12390
• Lewis, Davis, 1981, “Index, Context, and Content”, inPhilosophy and Grammar, Stig Kanger and Sven Ōhman(eds.), Dordrecht: D. Reider, 79–100.doi:10.1007/978-94-009-9012-8_6
• Loar, Brian, 2003, “Phenomenal Intentionality as the Basisof Mental Content”, inReflections and Replies: Essays onthe Philosophy of Tyler Burge, Martin Hahn and B. Ramberg (eds.),Cambridge, MA: MIT Press, 229–258.
• Ludwig, David, 2015, “Extended Cognition and the Explosionof Knowledge”,Philosophical Psychology, 28(3):355–368. doi:10.1080/09515089.2013.867319
• Luria, Alexander and Vygotsky, Lev 1930 [1992],Ape, Primitive Man,and Child: Essay in the History of Behavior, Evelyn Rossiter(trans.), Brighton: Harvester-Wheatsheaf.
• Lyre, Holger, 2018, “Socially Extended Cognition and SharedIntentionality”,Frontiers in Psychology, 9: 831.doi:10.3389/fpsyg.2018.00831
• Macdonald, Cynthia, 1990, “Weak Externalism and Mind-BodyIdentity”,Mind, 99(395): 387–404.doi:10.1093/mind/XCIX.395.387
• Mallon, Ron, Edouard Machery, Shaun Nichols, and Stephen Stich,2009, “Against Arguments from Reference”,Philosophyand Phenomenological Research, 79(2): 332–356.doi:10.1111/j.1933-1592.2009.00281.x
• McGinn, Colin, 1977, “Charity, Interpretation, andBelief”,The Journal of Philosophy, 74(9):521–535. doi:10.2307/2025795
• –––, 1982, “The structure ofcontent”, inThought and Object, A. Woodfield (ed.),Oxford: Oxford University Press, pp. 207–58.
• –––, 1989,Mental Content, Oxford:Blackwell.
• Menary, Richard, 2006, “Attacking the Bounds ofCognition”,Philosophical Psychology, 19(3):329–344. doi:10.1080/09515080600690557
• –––, 2007,Cognitive Integration: Attackingthe Bounds of Cognition, Basingstoke: Palgrave-Macmillan.
• ––– (ed.), 2010,The Extended Mind,Cambridge, MA: MIT Press.
• –––, 2015, “Mathematical cognition: a caseof enculturation”, inOpen MIND, T. Metzinger & J.M. Windt (eds.), Frankfurt am Main: MIND Group, 1–20.
• Newen, Albert, Leon De Bruin, and Shaun Gallagher (eds.), 2018,The Oxford Handbook of 4E Cognition, Oxford: OxfordUniversity Press.
• Noë, Alva (ed.), 2002,Is the Visual World a GrandIllusion? Special edition ofThe Journal of ConsciousnessStudies, Vol. 5–6.
• –––, 2004,Action in Perception,Cambridge, MA: MIT Press.
• O’Regan, J. Kevin and Alva Noë, 2001, “ASensorimotor Account of Vision and Visual Consciousness”,Behavioral and Brain Sciences, 24(5): 939–973.doi:10.1017/S0140525X01000115
• Prinz, Jesse, 2009, “Is Consciousness Embodied?”, inThe Cambridge Handbook of Situated Cognition, Philip Robbinsand Murat Aydede (eds.), Cambridge: Cambridge University Press,419–436. doi:10.1017/CBO9780511816826.022
• Pryor, James, 2007, “What’s Wrong with McKinsey-styleReasoning”, inInternalism and Externalism in Semantics andEpistemology, S. Goldberg (ed.), Oxford: Oxford University Press,177–200.
• Putnam, Hilary, 1975, “The Meaning of‘Meaning’”,Philosophical Papers, Vol. II: Mind,Language, and Reality, Cambridge: Cambridge UniversityPress.
• Rowlands, Mark, 1999,The Body in Mind: UnderstandingCognitive Processes, Cambridge: Cambridge University Press.doi:10.1017/CBO9780511583261
• –––, 2003,Externalism: Putting Mind andWorld Back Together Again, London: Acumen.
• –––, 2006,Body Language: Representation inAction, Cambridge, MA: MIT Press.
• –––, 2009, “Extended Cognition and theMark of the Cognitive”,Philosophical Psychology,22(1): 1–19. doi:10.1080/09515080802703620
• –––, 2010,The New Science of the Mind: FromExtended Mind to Embodied Phenomenology, Cambridge, MA: MITPress.
• Rumelhart, David E., James L. McClelland, and the PDP ResearchGroup, 1986,Parallel Distributed Processing: Explorations in theMicrostructure of Cognition 1: Foundations, Cambridge, MA: MITPress.
• Rupert, Robert D., 2004, “Challenges to the Hypothesis ofExtended Cognition”,Journal of Philosophy, 101(8):389–428. doi:10.5840/jphil2004101826
• –––, 2009,Cognitive Systems and theExtended Mind, New York: Oxford University Press.doi:10.1093/acprof:oso/9780195379457.001.0001
• Sartre, Jean-Paul, 1943 [1957],Being and Nothingness, H.Barnes (trans.), London: Methuen; originally published Paris:Gallimard, 1943.
• Segal, Gabriel, 2000,A Slim Book about Narrow Content,Cambridge, MA: MIT Press.
• Shapiro, Lawrence, 2004,The Mind Incarnate, Cambridge,MA: MIT Press.
• Siewert, Charles, 1998,The Significance ofConsciousness, Princeton: Princeton University Press.
• Slors, Marc, 2019, “Symbiotic Cognition as an Alternativefor Socially Extended Cognition”,PhilosophicalPsychology, 32(8): 1179–1203.doi:10.1080/09515089.2019.1679591
• Stalnaker, Robert, 1989, “On What’s In theHead”,Philosophical Perspectives, 3: 287–316.Reprinted inThe Nature of Mind, David Rosenthal (ed.),Oxford: Oxford University Press, 1991, 576–590.doi:10.2307/2214271
• Stich, Stephen, 1983,From Folk Psychology to CognitiveScience: The Case Against Belief, Cambridge, MA: MIT Press.
• Sutton, John, 2008,Philosophy and Memory Traces: Descartes toConnectionism, Cambridge: Cambridge University Press.
• –––, 2010, “Exograms and Interdisciplinarity:History, the Extended Mind, and the Civilizing Process”, inMenary 2010: 189–225.
• –––, 2015, “Remembering as PublicPractice: Wittgenstein, Memory, and Distributed CognitiveEcologies”, inMind, Language and Action: : Proceedings ofthe 36th International Wittgenstein Symposium, DanièleMoyal-Sharrock, Volker Munz, and Annalisa Coliva (eds.), Berlin: DeGruyter, 409–443. doi:10.1515/9783110378795.409
• Theiner, Georg, 2011,Res Cogitans Extensa: A PhilosophicalDefense of the Extended Mind Thesis, New York: Peter Lang.
• Vygotsky, Lev S., 1934 [1962],Thought and Language,Eugenia Hanfmann and Gertrude Vakar (trans.), Cambridge, MA: MITPress. [Originally published in Russian asMyshlenie i Rech,Moscow & Leningrad: Gosudarstvennoe sotsial'no-ekonomicheskoeizdatel'svo.]
• Wheeler, Michael, 2005,Reconstructing the Cognitive World:The Next Step, Cambridge, MA: MIT Press.
• –––, 2010, “In defense of extendedfunctionalism”, in Menary 2010: 245–270.
• Wikforss, Asa Maria, 2001, “Social Externalism andConceptual Errors”,The Philosophical Quarterly,51(203): 217–231. doi:10.1111/j.0031-8094.2001.00225.x
• Williamson, Timothy, 2000,Knowledge and Its Limits,Oxford: Oxford University Press. doi:10.1093/019925656X.001.0001
• Wilson, Robert A., 1994, “Wide Computationalism”,Mind, 103(411): 351–372.doi:10.1093/mind/103.411.351
• –––, 2004,Boundaries of the Mind: TheIndividual in the Fragile Sciences – Cognition, New York:Cambridge University Press. doi:10.1017/CBO9780511606847
• Wittgenstein, L., 1953,Philosophical Investigations, E.Anscombe, R. Rhees and G. H. Von Wright (eds.), E. Anscombe (trans.),Oxford: Blackwell.
• Yli-Vakkuri, Juhani and John Hawthorne, 2018,NarrowContent, Oxford: Oxford University Press.doi:10.1093/oso/9780198785965.001.0001

Academic Tools

	How to cite this entry.
	Preview the PDF version of this entry at theFriends of the SEP Society.
	Look up topics and thinkers related to this entry at the Internet Philosophy Ontology Project (InPhO).
	Enhanced bibliography for this entry atPhilPapers, with links to its database.

Other Internet Resources

• Lau, Joe and Max Deutsch, “Externalism About Mental Content”,Stanford Encyclopedia of Philosophy (Fall 2020 Edition),Edward N. Zalta (ed.), URL = <https://plato.stanford.edu/archives/fall2020/entries/content-externalism/>. [This was the previous entry on this topic in theStanfordEncyclopedia of Philosophy — see theversion history.]

Related Entries

externalism: and self-knowledge |functionalism |mental causation |mental content: narrow |physicalism

Acknowledgments

[Editor’s Note: The coauthors of the previous entry are alsocredited on the new entry since some content in Section 4 istaken from that entry.]