The Basic Idea

Perception is not something that happens to us, or in us. It is something we do. Think of a blind person tap-tapping his or her way around a cluttered space, perceiving that space by touch, not all at once, but through time, by skillful probing and movement. This is, or at least ought to be, our paradigm of what perceiving is. The world makes itself available to the perceiver through physical movement and interaction. All perception is touch-like in this way: perceptual experience acquires content thanks to our possession of bodily skills. What we perceive is determined by what we do and what we know how to do; it is determined by what we are ready to do. We enact our perceptual experience; we act it out.

To be a perceiver is to understand, implicitly, the effects of movement on sensory stimulation. Examples are ready to hand. An object looms larger in the visual field as we approach it, and its profile deforms as we move about it. A sound grows louder as we move nearer to its source. Movements of the hand over the surface of an object give rise to shifting sensations. As perceivers we are masters of this sort of pattern of sensorimotor dependence. This mastery shows itself in the thoughtless automaticity with which we move our eyes, head and body in taking in what is around us. We spontaneously crane our necks, peer, squint, reach for our glasses, or draw near to get a better look (or better to handle, sniff, lick or listen to what interests us). The central claim of the enactive¹ approach is that our ability to perceive not only depends on, but is constituted by, our possession of this sort of sensorimotor knowledge.

One implication of the enactive approach is that only a creature with certain kinds of bodily skills — e.g. a basic familiarity with the sensory effects of eye or hand movements, etc. — could be a perceiver. This is because, in effect, perceiving is a kind of skillful bodily activity. It may also be that only a creature capable of at least some primitive forms of perception could be capable of self-movement. Specifically, self-movement depends on perceptual modes of self-awareness, e.g. proprioception and also “perspectival self-consciousness”² (that is, the ability to keep track of one’s relation to the world around one).

A second implication of the enactive approach is that we ought to reject the idea — widespread in both philosophy and science — that perception is a process in the brain whereby the perceptual system constructs an internal representation of the world. No doubt perception depends on what takes place in the brain, and very likely there are internal representations in the brain (e.g. content-bearing internal states). What perception is, however, is not a process in the brain, but a kind of skillful activity on the part of the animal as a whole. The enactive view challenges neuroscience to devise new ways of understanding the neural basis of perception and consciousness.

This idea of perception as a species of skillful bodily activity is deeply counterintuitive. It goes against many of our preconceptions about the nature of perception. We tend, when thinking about perception, to make vision, not touch, our paradigm, and we tend to think of vision on a photographic model. You open your eyes and you are given, at once, a sharply focused impression of the present world in all its detail. On this view, the relation between moving and perceiving is only instrumental. It is like the relation between the lugging around of a camera and the resulting picture. The lugging is preliminary to and disconnected from the photograph itself. And so with perceiving. By moving yourself, you can come to occupy a vantage point from which, say, better to see your goal. And then, having seen your goal, you can better decide what to do. But the seeing, and the moving, have no more to do with each other than the photograph and the schlepping of the camera, or the boxer’s left hook, and the training that preceded it. Which is to say, they have a lot to do with each other, but the relation is nonconstitutive: the effectiveness of the punch is strictly independent of how the boxer learned to do it, and the qualities of the picture are independent of how the camera ended up where it was.

Susan Hurley (1998) has aptly called this simple view of the relation between perception and action the input-output picture: perception is input from world to mind, action is output from mind to world, thought is the mediating process. If the input-output picture is right, then it must be possible, at least in principle, to disassociate capacities for perception, action, and thought. The main claim of the enactive approach is that such a divorce is not possible. I doubt that it is even truly conceivable. All perception is intrinsically active. Perceptual experience acquires content thanks to the perceiver’s skillful activity. All perception is also intrinsically thoughtful. Blind creatures may be capable of thought, but thoughtless creatures could never be capable of sight, or of any genuine content-bearing perceptual experience. Perception and perceptual consciousness are types of thoughtful, knowledgeable activity.

Considerations of Content

Perception is a way of keeping track of how things are, but it is also a way of keeping track of one’s relation to how things are. This point has two aspects. First, we experience not only how things are, but also how they look (or sound, or feel, etc.) from here. We experience that the plate is round and that it looks elliptical from here. Its elliptical look from here is a genuine property of the plate—we see the shape and we see the perspectival shape from here—but it is also a relational property, one that depends on where “here” is. If we count perspectival properties (such as the ellpitical look) as belonging to the representational content of experience (Harman 1990; Noë 2002), then we are implicitly counting ourselves (or at least our vantage points or bodily locations) among those contents.

Second, it is hard to understand how one could keep track of how things are if one were not also capable of keeping track of the ways in which one’s perceptual experience depends on what one does. The perspectival shape of the plate changes as one moves. Indeed, it seems likely that our practical grasp on the way it changes as we move is precisely the way we succeed in experiencing its roundness. More generally, how things look (what one sees) changes with every movement of the eye or turn of the head.

Here’s the crux: these perspectival aspects of perceptual content are only partly determined by how things are. They depend further on one’s relation to how things are. Any account of perception that ignores this dependence of how things look on one’s movements (that is, on changes in one’s relation to how things are), and that in effect ignores the distinctively perspectival aspects of perceptual content, will fail to provide an adequate account of what perception is.

Let’s back up and go over this more carefully. Perceptual content—what philosophers call representational content: how the experience presents the world as being—is two-dimensional. It can vary along a factual dimension, in regard to how things are. And it can vary along a perspectival dimension, in regard to how things look from the vantage point of the perceiver. Visual experience (as well as perceptual experience in other modalities) always has both these dimensions of content.

Now there is no general requirement that for an experience to be veridical, it must be completely veridical. You can succeed in seeing a spoon, for example, even if the spoon nonveridically looks bent (because it is in water, say). And so, likewise, there is no hard requirement that for a perceptual experience to be veridical, it must be veridical along both dimensions of its content. We frequently enjoy visual experiences that are perspectivally nonveridical but factually veridical. This is the case, for example, when you spy on someone from under water using a periscope. The experiences you have with the periscope represent how things are, but they misrepresent your relation to how things are, that is, they misrepresent the perspectival content of your experience. When you watch a live sporting event on television, you are able to track what’s happening, but you do so in a perspectivally nonveridical way. Perhaps you adopt the standpoint of one or more cameras. Crucially, you don’t correctly or veridically experience the event’s spatial relation to yourself. It would be dogmatic to deny that you see the sporting event, that you see it “through” or by means of the television cameras. But it would be just as dogmatic to insist that there is no difference whatsoever between normal perception, in the here and now, and televisual perception. The difference is one that is now easy to explain: when you witness events in person, your experiences track not only how things are, but also how things are in relation to you.

For an experience to be veridical simpliciter, then, is for it to be veridical along both factual and perspectival dimensions. But we have already drawn attention to the fact that veridicality is not sufficient for perception. Just as there are two dimensions along which an experience can be veridical, so there are two dimensions along which it can be veridically hallucinatory. Things can turn out to be the way they seem, even though their seeming that way is independent of the fact that they are that way, and they can turn out to stand in the relation to you in which they seem to stand, even though your relation to how things are has no effect on how they seem. When you take your experience at face value, you encounter it as raising questions not only about how things are, but about how we stand in relation to how things are. To be a perceiver, then, you must understand, implicitly, that your perceptual content varies as things around you change, and that it varies in different ways as you move in relation to things around you.

A Puzzle about Perception: Experiential Blindness

For those who see, it is difficult to resist the idea that being blind is like being in the dark. When we think of blindness this way, we imagine it as a state of blackness, absence and deprivation. We suppose that there is a gigantic hole in the consciousness of a blind person, a permanent feeling of incompleteness. Where there could be light, there is no light.

This is a false picture of the nature of blindness. The longterm blind do not experience blindness as a disruption or an absence. This is not because, as legend has it, smell, touch and hearing get stronger to compensate for the failure to see (although this may be true to some degree; see Kaufman et al. 2002). It’s because there is a way in which the blind do not experience their blindness at all. Consider, you are unable visually to discern what takes place in the room next door, but you do not experience this inability as a gaping hole in your visual awareness. Likewise, you don’t encounter the absence of the sort of olfactory information that would be present to a bloodhound as something missing in your sense of smell. Nor do you notice the absence of information about the part of the visual field that falls on the “blind spot” of your retina. In this same way the blind do not encounter their blindness as an absence.

It is easy to demonstrate that there are or could be forms of blindness that were not at all like being in the dark. Imagine that you are out in a fog so dense that no matter where you turn or how you strain you only experience a homogeneous whiteness. This is what psychologists call a Ganzfeld (Metzger 1930, described in Gibson 1979: 150-151). You can reproduce the experience of a Ganzfeld by placing half a ping-pong ball over each eye (Hochberg, Treble, & Seaman 1951, Gibson and Wadell 1952; Block 2001). Gibson used this method to argue that stimulation of the retina by light is not sufficient for vision. For even though you enjoy a pattern of visual stimulation — in some sense you see the Ganzfeld — you are in effect blind. You have visual impressions, but they are bleached of content.

The enactive view of perception predicts that there are, broadly speaking, two different kinds of blindness. First, there is blindness due to damage or disruption of the sensitive apparatus. This is the familiar sort of blindness. It would include blindness caused by cataracts, by retinal disease or injury, or by brain lesion in the visual cortex. Second, there is blindness due not to the absence of sensation or sensitivity, but rather to the person’s (or animal’s) inability to integrate sensory stimulation with patterns of movement and thought. Let’s call this second kind of blindness experiential blindness because it is blindness despite the presence of something like normal visual sensation.

Does experiential blindness actually occur? If it does, then we must reject the input-output picture. To see is not just to have visual sensations, it is to have visual sensations that are integrated, in the right sort of way, with bodily skills. Experiential blindness would provide evidence for the enactive approach to perception.

There’s good reason to believe that experiential blindness does occur. As an example, consider attempts to restore sight in congenitally blind individuals whose blindness is due to cataracts. Cataracts impair the eye’s sensitivity by obstructing light on its passage to the retina. From the standpoint of the input-output picture, it would be natural to suppose that removing the cataract would be like sweeping aside the blinds, letting in the light and thus enabling normal vision. This is not in fact what the medical literature on this teaches us. What we learn from the case studies is that the surgery restores visual sensation, at least to a significant degree, but that it does not restore sight. In the period immediately after the operation, patients suffer blindness despite rich visual sensations. That is to say, they suffer experiential blindness.

Experiential blindness exists and is important for two reasons. First, it lends support for the enactive view. Genuine perceptual experience depends not only on the character and quality of stimulation, but on our exercise of sensorimotor knowledge. The disruption of this knowledge, does not leave us with experiences we are unable to put to use. It leaves us without experience. For mere sensory stimulation to constitute perceptual experience — that is, for it to have genuine world-presenting content — the perceiver must possess and make use of sensorimotor knowledge.

Second, it provides a counter-example to the more traditional input-output picture. Kant famously said that intuitions without concepts are blind. The present point is that intuitions — patterns of stimulation — without knowledge of the sensorimotor significance of those intuitions, are blind. Crucially, the knowledge in question is practical knowledge; it is know-how. To perceive you must be in possession of sensorimotor, bodily skill.

The Joys of Seeing

A natural line of objection to the enactive approach goes like this: True, our perceptual capacities are bound up with bodily skill and action. We use our eyes to guide our movements and to enable action. But that is not always the case. Sometimes we see not in order to act, but just in order to know, or to enjoy our experiences of seeing. When you lie back and watch the passing clouds, or when you visit an art gallery, or watch TV, you are not using visual skills for purposes of action. Pylyshyn (2001) has made this point; he adds that “Much of what we see guides our action only indirectly by changing what we believe and perhaps what we want.”

This criticism of the enactive view would seem to gain support from the study of neurological disorders of vision. Patients with optic ataxia (resulting from lesions in posterior parietal cortex) are unable to make use of what they see to guide movements.

This criticism rests on a misunderstanding of the enactive approach. The basic claim of the enactive approach is that the perceiver’s ability to perceive is constituted (in part) by sensorimotor knowledge (that is, by practical grasp of the way sensory stimulation varies as the perceiver moves). The enactive approach does not claim that perception is for acting or for guiding action. The existence of optic ataxia, therefore, does not undercut the enactive view, for from the fact that a patient suffers optic ataxia, it doesn’t follow they he or she lacks the relevant sensorimotor knowledge. What would undercut it would be the existence of perception in the absence of the bodily skills and sensorimotor knowledge which, on the enactive view, are constitutive of the ability to perceive. Could there be an entirely inactive, an inert perceiver?

Before we turn to this question, consider a simpler worry. Paralysis is certainly not a form of blindness. But isn’t that precisely what the enactive view requires, that the paralyzed be experientially blind? No. The enactive view requires that perceivers possess a range of pertinent sensorimotor skills. It seems clear that quadriplegics have the pertinent skills. Quadriplegics can move their eyes and head, and to some extent, at least with help from technology, they can move their bodies with respect to the environment (e.g. by using a wheelchair). More importantly, paralysis does not undermine the paralyzed person’s practical understanding of the ways movement and sensory stimulation depend on each other. Even the paralyzed, whose range of movement is restricted, understand, implicitly and practically, the significance of movement for stimulation. They implicitly understand, no less than those who are not disabled, that movement of the eyes to the left produces rightward movement across the visual field, et cetera. Paralyzed people can’t do as much as people who are not paralyzed, but they can do an awful lot; whatever the scope of their limitations, they draw on a wealth of sensorimotor skill that informs and enables them to perceive.

Even tetraplegics, who are without sensation as well as movement, live extremely active lives. As the clinical neurophysiologist Jonathan Cole remarks, “Try balancing in a chair without any sensation from the neck down” (personal communication, but see his 2004). Tetraplegics are continuously engaged in the task of orienting themselves in relation to the world around them and to gravity (as Cole 2004 discusses).

There is in fact strong empirical evidence that a more thoroughgoing paralysis – for example, of the eyes themselves – would cause blindness. In normal perceivers, the eyes are in nearly constant motion, engaging in saccades (sharp, ballistic movements) and mircosaccades several times a second. If the eyes were to cease moving, they’d lose their receptive power. In particular, it has been shown that images stabilized on the retina fade from view (Ditchburn & Ginsborg 1952; Riggs, Ratliff, Cornsweet & Cornsweet 1953; Krauskopf 1963; Yarbus 1967). This is probably an instance of the more general phenomenon of sensory fatigue thanks to which we do not continuously feel our clothing on our skin, the glasses resting on the bridge of our nose, or a ring on our finger. This suggests that some minimal amount of eye and body movement is necessary for perceptual sensation.

There is also developmental evidence that normal vision depends not only on movement of the body relative to the environment, but on self-actuated movement. Held and Hein (1963) performed an experiment in which two kittens were harnessed to a carousel. One of the kittens was harnessed in such a way that it stood firmly on the ground. The other kitten was suspended in the air. As the one kitten walked, both kittens moved in a circle. As a result, they received identical visual stimulation, but only one of them received that stimulation as a result of self-movement. Remarkably (but not surprisingly from an enactive viewpoint) only the self-moving kitten developed normal depth perception (not to mention normal paw-eye coordination). From an enactive standpoint, we can venture an explanation for this: only through self-movement can one test and so learn the relevant patterns of sensorimotor dependence.

There are, however, deeper and more compelling reasons to be skeptical of the very idea that there could be a truly passive, inert perceiver. A few preliminary remarks now can set us on the path.

The extraordinary case of Ian Waterman, documented by Jonathan Cole (1991), serves as an illustration. Waterman, as a young man, took ill with a virus that produced a dramatic and far-reaching neuropathy. Although his motor nerves remained unaffected, he lost all sensation from the neck down, except for the sensation of pain (e.g. pin pricks) and temperature. In particular, he lost what is sometimes called “the sixth sense,” namely, the sense of movement and position known as proprioception and kinaesthesis. Waterman was initially, in effect, paralyzed. Despite the fact that he possessed a normally functioning motor system, he was unable to bring his limbs and body under his control. In the absence of proprioceptive feedback, he was unable to move. Eventually, he regained a good measure of motor skill by learning to substitute vision for muscular sense. By intense visual concentration, he was able to control his body movements. However, if he were put into a position in which he could not view his body (reclining back on a couch, say), or if the lights were to go out, he would collapse to the ground, unable to move. As Cole says, in the case of Ian Waterman, for his body to be out of sight was, literally, for it to be out of mind.

What would Ian Waterman have done if he had been blind as well? Let’s consider a made-up case. Suppose that you suffer from a neuropathy like Waterman’s, that is to say, that you have lost all sense of movement, position and posture, but imagine that you are, in addition, deaf and blind. Let’s further imagine that you have normal sensation from the neck down. Strictly speaking, this last detail is not consistent with the supposition that you lack all proprioception, since proprioception depends in part on cutaneous sensitivity (in addition to the activation of muscle spindles and tendon receptors). But let’s put this complication aside and imagine that you have normal tactile sensation, but that you lack a sense of movement, position and posture, and that you are deaf and blind. To imagine this, then, is to imagine that you are inert, that you are radically unable to act with your body. It is to imagine that your body has been lost to you as an animated part of yourself.

Now let us ask, would you be able to perceive by touch? Could you enjoy tactile experience of the world around you? By hypothesis your cutaneous sensory receptors are intact, so there is no question whether you can feel, that is, have tactile sensations. The question is, in having tactile sensations, would you perceive how things are around you?

In general, there are reasons to doubt that tactile sensation or feeling is sufficient for tactile perception. To perceive by touch, for example, the rectangularity of something you hold in your hands, or the layout of furniture in a room (as a blind person might, by moving around and reaching and touching), is not merely to have certain feelings or sensations. After all, the rectangularity is not captured by specific sensations. There is no unitary sensation or feel of a rectangle. The rectangularity is made available to you, in touch, by your active touching (probing, prodding, stroking, rubbing, squeezing) with your hands. What informs you of the shape of what you feel or hold is not the intrinsic character of your sensations, but rather your implicit understanding of the organization or structure of your sensations. The shape is made available thanks to the way in which your sensations covary or would covary with actual or possible movements. In perceiving the thing as rectangular, you understand, implicitly, that, for example, if you move your hands like so, you’ll encounter corners that stand in a certain relation to each other, et cetera. The same sort of point can be made about the tactile perception of the layout of furniture in the room. Your tactile impression that things are arranged thus and such consists not in the sensations in your hands and feet, but in the way those sensations result from attentive movement through the space. What is informative is the fact that you bump your foot here, that you cannot press forward there, et cetera. You perceive the furniture layout when you understand the way your sensations are fixed as a function of movement through the space. In this way, sensation and sensorimotor knowledge work together to produce the perception of the spatial layout of the room.

For this sort of reason it seems plausible that feeling alone is not sufficient to enable you to learn about or discover the properties of objects or layouts around you. It is altogether unclear, in the extreme case of inert perception we are imagining, that you would be able to learn how things are around you, for you would be unable to probe in response to sensations, and so would be unable, even in thought, to coordinate them. How could you perceive the object as rectangular without moving it across your body surfaces, or without moving your body surfaces across it?

To this it might be responded that you could at least perceive heat say, or texture. For these simple tactile qualities, it might seem that feeling is sufficient for tactile perception. This is plausible, but we need to be cautious. You will have sensations, to be sure, but will they amount to perception of how things are, even with respect to heat or texture? Because you are completely inert, you may be unable to localize your sensations on your body. Suppose someone presses, say, a warm spoon against your thigh. What will you experience? A feeling of warmth on your thigh? Or merely a feeling of warmth? In either case, your experience will be confined to the character of your own sensations. Your would-be perception of the warmth of something will collapse into the mere sensation of warmth somewhere (perhaps conjoined with the inference that that sensation is likely to have an external source). Such a sensation-plus-guesswork falls short of constituting perceptual experience with content (at least of the normal sort). At best, it would seem, it is a primitive antecedent of the latter.

Remember, what is in question here is the experience of one who is radically inert. Ian Waterman, and others with similar conditions, are not radically inert. They are able to locate sensations of heat on their legs (say); without proprioception (or vision, say), they are unable to locate the leg, however, in surrounding space. My suggestion is that for one whose sensations bear no familiar dependence on patterns of movement, even this localization on the surfaces of one’s own body would be impossible.

It might be objected that sometimes mere touch is enough for perception. A sense of touch, for example, signals the presence of a fly, or some other object. Yes, and no. We do experience the presence and location of a fly (say) by the merest sense of touch on the skin, but this is only because we also possess the sensorimotor skills needed to interpret that touch as referring to a type of movement or position in space. We spontaneously withdraw our arm from the touch, for example, and in this way we give expression to the understanding that such a movement of the arm is a movement away from the point of contact with the fly. What would it be to experience the touch as an instant of contact with the fly, if one were not also able, thus, to understand the way movements would alter one’s relation to that point in space?

The enactive view insists that mere feeling is not sufficient for perceptual experience (that is, for experience with world-representing content). O’Shaughnessy (2000) has argued (I think rightly) that it is not even necessary for perceptual experience. You could perceive the presence of a wall by reaching out and pressing it with your numb hand. Your ability to do that probably depends on your having feelings elsewhere. But, as O’Shaughnessy points out, those feelings are not part of your experience; they do not belong to the scope of your attention in perceiving the wall by touch. This point is nicely illustrated by the case of a blind person perceiving by means of a cane. There is no feeling at the end of the cane, yet it is with the end of the cane that the blind person makes contact with the world. It is probable that the ability thus to perceive depends on one’s capacity for sensation (in the hand that holds the cane, say). But crucially, sensations in your hand are not constituents of your cane-based perceptual experience of the environment ³.

On the enactive view, all perception is in these respects like touch. Mere sensation, mere stimulation, falls short of perceptual awareness. As stated earlier, for perceptual sensation to constitute experience, that is, for it to have genuine representational content, the perceiver must possess and make use of sensorimotor knowledge. To imagine a truly inert perceiver is to imagine someone without the sensorimotor knowledge needed to enact perceptual content.

NB: The material in this essay is taken from A. Noë, Action In Perception (The MIT Press, 2004/in press.)

Works Cited

Block, N. 2001. Behaviorism revisited. Behavioral & Brain Sciences 24: 977–978.

Cole, J. 1991 Pride and the Daily Marathon. London: Duckworth.

Cole, J. 2004. Still Lives: Narratives in Spinal Cord Injury. Cambridge, MA: The MIT Press.

Ditchburn, R. W., and B. L. Ginsborg. 1952. Vision with a stabilized retinal image. Nature 170: 36–37.

Gibson, J. J. 1979. The Ecological Approach to Visual Perception. Hillsdale, NJ: Lawrence Erlbaum.

Gibson, J. J., and D. Wadell. Homogeneous retina stimulation and visual perception. American Journal of Psychology 64: 263–270.

Harman, G. 1990. The intrinsic quality of experience. In Philosophical Perspectives 4, ed. J. Tomberlin, 32-51. Northridge, CA: Ridgeview.

Held, R., and A. Hein. 1963. Movement produced stimulation in the development of visually guided behavior. Journal of Comparative and Physiological Psychology 56: 873–876.

Hochberg, J. E., W. Triebel, and G. Seaman. 1951. Colo adaptation under conditions of hogeneous visual stimulation (Ganzfeld). Journal of Experimental Psychology 41: 153–159.

Hume, D. [1739–1740] 1975. A Treatise of Human Nature, 2nd ed., ed. L. A. Selby-Bigge, rev. P. H. Nidditch. Oxford: Clarendon Press.

Humphrey, N. 1992. A History of the Mind. New York: Simon & Schuster.

Hurley, S. L. 1998. Consciousness in Action. Cambridge, MA: Harvard University Press.

Hurley, S., and A. Noë. 2003b. Neural plasticity and consciousness: Reply to Block. Trends in Cognitive Sciences 7, no. 8 (August): 342.

Kaufman, T., H. Théoret, and A. Pasual-Leone. 2002. Braille character discrimination in blindfolded human subjects. Neuroreport 13, no. 16 (April): 1–4.

Krauskopf, J. 1963. Effects of retinal stabilization on the appearance of heterochromatic targets. Journal of the Optical Society of America 53: 741–744.

Metzger, W. 1930 Optische Untersuchungen in Ganzfeld II. Psychlogische Forschung 13: 6–29.

Noë, A. 2002. On what we see. Pacific Philosophical Quarterly 83: 1.

Noë, A. 2004/in press. Action in Perception. Cambridge, MA: The MIT Press.

O’Regan, J. K., and A. Noë. 2001 A sensorimotor approach to vision and visual consciousness. Behavioral and Brain Sciences 24, no. 5: 883-975.

O’Shaughnessy, B. 2000. Consciousness and the World. New York: Oxford University Press.

Pylyshyn, Z. W. 2001. Seeing, acting, and knowing. [Commentary on O’Regan and Noë 2001.] Behavioral and Brain Sciences 24, no. 5.

Note

1.The term “enactive” was first used by Francisco Varela and Evan Thompson (Varela, Thompson and Rosch 1991). They call “enactive” a way of thinking about the mind according to which 1) the subject of mental states is taken to be the embodied, environmentally situated animal; 2) the animal and the environment are thought of as a pair, standing in a relation of being essentially coupled and reciprocally determining; 3) perceptual and other cognitive states are thought of in terms of activity on the part of the animal and as nonrepresentational; 4) the mental life of a creature is taken to be an autonomous domain for the sort of investigation pursued within the philosophical movement known as Phenomenology.

What I call the enactive approach has been called the sensorimotor approach by Kevin O’Regan and me (2001). Susan Hurley and I, in joint work, have deployed a different term: the dynamic sensorimotor account (2003). I leave aside the question of whether these usages conform to that of Varela and Thompson.

2.Perspectival self-consciousness is a term of Hurley’s (1998). The role of proprioception in self-actuated movement is an important theme in the work of Brian O’Shaughnessy. See his Consciousness and the World (2000). Whether proprioception should be thought of as a mode of perceptual awareness of one’s body is unsettled.

3.Nicholas Humphrey (1992) has developed an account of perceptual consciousness that takes as basic the sharp distinction between sensation and mere perception. Humphrey argues that sensation informs us as to what is going on with us (in or on our bodies), whereas perception is directed to the world. Crucially, on Humphrey’s view, as on my own, mere sensation or feeling is not sufficient for perception.