Fred Dretske

If consciousness is good for something, conscious things must differ in some causally relevant way from unconscious things. If they do not, then, as Davies and Humphrey (1993: 4-5) conclude, too bad for consciousness: "psychological theory need not be concerned with this topic."

Davies and Humphrey are applying a respectable metaphysical idea--the idea, namely, that if X's having C does make a difference to what X does, if X's causal powers are in no way altered by its possession of C, then nothing X does can be explained by its being C. A science dedicated to explaining the behavior of X need not, therefore, concern itself with C. That is why being an uncle is of no concern to the psychology (let alone the physics) of uncles. I am an uncle, yes, but my being so does not (causally speaking[1]) enable me to do anything I would not otherwise be able to do. The fact that I am an uncle (to be distinguished, of course, from my believing I am an uncle) does not explain anything I do. From the point of view of understanding human behavior, then, the fact that some humans are uncles is epiphenomenal. If consciousness is like that--if it is like being an uncle--then, for the same reason, psychological theory need not be concerned with it. It has no purpose, no function. No good comes from being conscious.

Is this really a worry? Should it be a worry? The journals and books, I know, are full of concern these days about the role of consciousness.[2] Much of this concern is generated by startling results in neuropsychology (more of this later). But is there a real problem here? Can there be a serious question about the advantages, the benefits, the good, of being conscious? I don't think so. It seems to me that the flurry of interest in the biological function of consciousness betrays a confusion about several quite elementary distinctions. Once the distinctions are in place--and there is nothing especially arcane or tricky about them--the advantages (and, therefore, the good) of consciousness is obvious.

1. The First Distinction: Conscious Beings vs. Conscious States.

Stones are not conscious, but we are.[3] And so are many animals. We are not only conscious (full stop), we are conscious of things--of objects (the bug in my soup), events (the commotion in the hall), properties (the color of his tie), and facts (that he is following me). Following Rosenthal (1990), I call all these creature consciousness. In this sense the word is applied to beings who can lose and regain consciousness and be conscious of things and that things are so.

Creature consciousness is to be distinguished from what Rosenthal calls state consciousness--the sense in which certain mental states, processes, events and activities (in or of conscious beings) are said to be either conscious. or unconscious. When we describe desires, fears, and experiences as being conscious or unconscious we attribute or deny consciousness, not to a being, but to some state, condition or process in that being. States (processes, etc.), unlike the creatures in whom they occur, are not conscious of anything or that anything is so although we can be conscious of them and their occurrence in a creature may make that creature conscious of something.

That is the distinction. How does it help with our question? I'll say how in a moment, but before I do, I need to make a few things explicit about my use of relevant terms. Not everyone (I've discovered) talks the way I do when they talk about consciousness. So let me say how I talk. My language is, I think, entirely standard (I use no technical terms), but just in case my readers talk funny, I want them to know how ordinary folk talk about these matters.

For purposes of this discussion and in accordance with most dictionaries I regard "conscious" and "aware" as synonyms. Being conscious of a thing (or fact) is being aware of it. Alan White (1964) describes interesting differences between the ordinary use of "aware" and "conscious". He also describes the different liaisons they have to noticing, attending, and realizing. Though my use of these expressions as synonymous for present purposes blurs some of these ordinary distinctions, I think nothing essential to this topic is lost by ignoring the nuances.

I assume, furthermore, that seeing, hearing, smelling, tasting and feeling are specific forms--sensory forms--of consciousness. Consciousness is the genus; seeing, hearing, and smelling are species (the traditional five sense modalities are not, of course, the only species of consciousness). Seeing is visual awareness. Hearing is auditory awareness. Smelling burning toast is becoming aware--in an olfactory way--of burning toast. One might also see the burning toast. And feel it. These are other modalities of awareness, other ways of being conscious of the toast.[4] You may not pay much attention to what you see, smell, or hear, but if you see, smell or hear it, you are conscious of it.

This is important. I say that if you see (hear, etc.) it, you are conscious of it. The "it" refers to what you are aware of (the burning toast), not that you are aware of it. There are two ways one might, while being aware of burning toast, fail to be aware that one is aware of it. First, one might know one is aware of something, but not know what it is. "What is that I smell," is the remark of a person who might well be aware of (i.e., smell) burning toast without being aware that he is aware of burning toast. Second, even if one knows what it is one is aware of--knows that it is burning toast--one might not understand what it means to be aware of it, might not, therefore, be aware that one is aware of it. A small child or an animal--creatures who lack the concept of awareness--can be conscious of (i.e., smell) burning toast without ever being aware that they are aware of something. Even if they happen to know that what they are aware of is burning toast, they do not know--are not, therefore, aware--that they are aware of it.

The language here is a bit tricky, so let me give another example. One can be aware of (hear) a french horn without being aware that that is what it is. One might think it is a trombone or (deeply absorbed in one's work) not be paying much attention at all (but later remember hearing it). If asked whether you hear a french horn, you might well think and say (falsely) that you are not. Not being aware that you are aware of a french horn does not mean you are not aware of a french horn. Hearing a french horn is being conscious of a french horn. It is not--not necessarily anyway--to be aware that it is a french horn or aware that you are aware of it (or, indeed, anything). Mice who hear--and thereby become auditorily aware of--french horns never become aware that they are aware of anything--much less of french horns.[5]

So, once again, when I say that if you see, hear, or smell something you must be conscious of it , the "it" refers to what you are aware of (burning toast, a french horn), not what it is you are aware of or that you are aware of it . To be conscious of an F is not the same as being conscious that it is an F and certainly not the same as being conscious that one is conscious of an F. Animals (not to mention human infants) are presumably aware of a great many things (they see, smell, and feel the things around them). Nonetheless, without the concept of awareness, and without concepts for most of the things they are aware of, they are not aware of what they are aware of nor that they are aware of it. What they are conscious of is burning toast. They are not aware that it is burning toast nor that they are aware of it.

So much for terminological preliminaries. I have not yet said anything that is controversial. Still, with only these meagre resources, we are in a position to usefully divide our original question into two more manageable parts. Questions about the good of consciousness, about its purpose or function, can either be questions about creature consciousness or about state consciousness. I will, for the rest of this section, take them to be questions about creature consciousness. I return to state consciousness in the next section.

If, then, we take our question about the purpose of consciousness as a question about creature consciousness, about the benefits that consciousness affords the animals who are conscious, the answer would appear to be obvious. If animals could not see, hear, smell and taste the objects in their environment--if they were not (in these ways) conscious--how could they find food and mates, avoid predators, build nests, spin webs, get around obstacles, and, in general, do the thousand things that have to be done in order to survive and reproduce?

Let an animal--a gazelle, say--who is aware of prowling lions--where they are and what they are doing--compete with one who is not and the outcome is predictable. The one who is conscious will win hands down. Reproductive prospects, needless to say, are greatly enhanced by being able to see and smell predators. That , surely, is an evolutionary answer to questions about the benefits of creature consciousness.[6] Take away perception--as you do, when you remove consciousness--and you are left with a vegetable. You are left with an eatee, not an eater. That is why the eaters of the world (most of them anyway) are conscious.

This answer is so easy I expect to be told that I'm not really answering the question everyone is asking. I will surely be told that questions about the function of consciousness are not questions about why we--conscious beings--are conscious. It is not a question about the biological advantage of being able to see, hear, smell, and feel (thus, being conscious of) the things around us. It is, rather, a question about state consciousness, a question about why there are conscious states, processes, and activities in conscious creatures. Why, for instance, do conscious beings have conscious experiences and thoughts?

2. The Second Distinction: Objects vs. Acts of Awareness.

If our question is a question about the benefits of state consciousness, then, of course, we have preliminary work to do before we start answering it. We have to get clear about what a conscious state (process, activity) is. What, for instance, makes an experience, a thought, a desire, conscious? We all have a pretty good grip on what a conscious animal is. It is one that is--via some perceptual modality--aware of things going on around (or in) it. There are, no doubt, modes of awareness, ways of being conscious, which we do not know about and will never ourselves experience. We do not, perhaps, understand bat phenomenology or what it is like for dogfish to electrically sense their prey. But we do understand the familiar modalities--seeing, hearing, tasting and so on-- and these, surely, qualify as ways of being conscious. So I understand, at a rough and ready level, what someone is talking about when they talk about a creature's being conscious in one of these ways. But what does it mean to speak, not of an animal being conscious in one of these ways, but of some state, process, or activity in the animal as being conscious? States, remember, aren't conscious of anything. They are just conscious (or unconscious) full stop. So what kind of property is this? And what makes a state conscious? Until we understand this, we won't be in a position to even speculate about what the function of a conscious state is.

There are, as far as I can see, only two options for making sense out of state consciousness. Either a state is made conscious by its being an object or by its being an act of creature consciousness. A state of creature S is an object of creature consciousness by S being conscious of it. A state of creature S is an act of creature consciousness, on the other hand, not by S being aware of it, but by S being made aware (so to speak) with it--by its occurrence in S making (i.e., constituting) S's awareness and, therefore, if there is an object that stands in the appropriate relation to this awareness, S's awareness of some object. When state-consciousness is identified with a creature's acts of awareness, the creature need not be aware of these states for them to be conscious. What makes them conscious is not S's awareness of them, but their role in making S conscious--typically (in the case of sense perception), of some (external) object.

Consider the second possibility first. On this option, a conscious state (e.g., an experience) is one that makes an animal conscious. When a gazelle sees a lion, its visual experience of the lion qualifies as a conscious experience, a conscious state, because it makes the gazelle visually conscious of the lion. Without this experience, the gazelle would not be visually aware of anything--much less a lion.

There are, to be sure, states of (processes and activities in) the gazelle which are not themselves conscious but which are necessary to make the animal (visually) aware of the lion. Without eyes and the assorted events occurring therein, the animal would not see anything--would not, therefore, be visually conscious of lions or any other external object. This is true enough, but it is irrelevant to the act conception of state-consciousness. According to the act conception of state-consciousness, a conscious visual state is one without which the creature would not be visually conscious of anything--not just external objects. The eyes may be necessary for the gazelle to be conscious of (i.e., to see) the lion, but they are not necessary for the animal to be conscious, to have the sort of visual experiences that, when things are working right, are normally caused by lions and are, therefore, experiences of lions. A conscious visual state is one that is essential not just to a creature's visual awareness of this or that kind of thing (e.g., external objects), but to its visual awareness of anything--including the sorts of "things" (properties) one is aware of in hallucinations and dreams. That is why, on an act account of state consciousness, the processes in early vision, those occurring in the retina and optic nerve, are not conscious. They may be necessary to a creature's visual awareness of external objects, but they are not essential to visual awareness. Even without them, the creature can still dream about or hallucinate the things it can no longer see. The same acts of awareness can still occur. They just don't have the same (according to some, they don't have any) objects

If we agree about this--agree, that is, that conscious states are states that constitute creature consciousness (typically, of things), then the function, the good, of state consciousness is evident. It is to make creatures conscious, and if (see above) there is no problem about why animals are conscious, then, on the act conception of what a conscious state is, there is no problem about why states are conscious. Their function is to make creatures conscious. Without state consciousness, there is no creature consciousness. If there is a biological advantage in gazelles being aware of prowling lions, then there is a purpose in gazelles having conscious experiences. The experiences are necessary to make the gazelle conscious of the lions.

I do not expect many people to be impressed with this result. I expect to be told that the states, activities, and processes occurring in an animal are conscious not (as I have suggested) if the animal is conscious with them, but, rather, if the animal (in whom they occur) is conscious of them. A conscious state is conscious in virtue of being an object, not an act, of creature awareness. A state becomes conscious, according to this orthodox line of thinking, when it becomes the object of some higher-order thought or experience. Conscious states are not states that make the creatures in whom they occur conscious; it is the other way around: creatures make the states that occur in them conscious by becoming conscious of them.

Since the only way states can become an object of consciousness is if there are higher order acts which have them as their objects, this account of state consciousness has come to be called a HO (for Higher Order ) theory of consciousness. It has several distinct forms, but all versions agree that an animal's experience (of lions, say) remains unconscious (or, perhaps, non-conscious) until the animal becomes aware of it. A higher order awareness of one's lion-experience can take the form of a thought (a HOT theory)--in which case one is aware that (i.e., one thinks that) one is experiencing a lion--or the form of an experience (a HOE theory)--in which case one is aware of the lion-experience in something like the way one is aware of the lion: one experiences one's lion-experience (thus becoming aware of one's lion-experience) in the way one is aware of (experiences) the lion.

I have elsewhere (Dretske 1993, 1995) criticized HO theories of consciousness, and I will not repeat myself here. I am more concerned with what HO theories have to say--if, indeed, they have anything to say--about the good of consciousness. If conscious states are states we are, in some way, conscious of, why have conscious states? What do conscious states do that unconscious states don't do? According to HO theory, we (i.e., creatures) could be conscious of (i.e., see, hear, and smell) most of the objects and events we are now conscious of (and this includes whatever bodily conditions we are proprioceptively aware of) without ever occupying a conscious state. To be in a conscious state is to be conscious of the state, and since the gazelle, for example, can be conscious of a lion without being conscious of the internal states that make it conscious of the lion, it can be conscious of the lion--i.e., see, smell, feel and hear the lion--while occupying no conscious states at all. This being so, what is the purpose, the biological point, of conscious states? It is awareness of the lion that is useful, not awareness of one's lion experiences. It is the lions, not the lion-experiences, that are dangerous.

On an object conception of state-consciousness, it is difficult to imagine how conscious states could have a function. To suppose that conscious states have a function would be like supposing that conscious ball bearings--i.e., ball bearings we are conscious of--have a function. If a conscious ball bearing is a ball bearing we are conscious of, then conscious ball bearings have exactly the same causal powers as do the unconscious ones. The causal powers of a ball bearing (as opposed to the causal powers of the observer of the ball bearing) are in no way altered by being observed or thought about. The same is true of mental states like thoughts and experiences. If what makes an experience or a thought conscious is the fact that S (the person in whom it occurs) is, somehow, aware of it, then it is clear that the causal powers of the thought or experience (as opposed to the causal powers of the thinker or experiencer) are unaffected by its being conscious. Mental states and processes would be no less effective in doing their job--whatever, exactly, we take that job to be--if they were all unconscious. According to HO theories of consciousness, then, asking about the function of conscious states in mental affairs would be like asking about the function of conscious ball bearings in mechanical affairs.

David Rosenthal (a practising HOT theorist) has pointed out to me in correspondence that though experiences do not acquire causal powers by being conscious, there may nonetheless be a purpose served by their being conscious. The purpose might be served, not by the beneficial effects of a conscious experience (conscious and unconscious experiences have exactly the same effects acccording to HO theories), but by the effects of the higher-order thoughts that makes the experience conscious. Although the conscious experiences don't do anything the unconscious experiences don't do, the creatures in which conscious experiences occur are different as a result of having the higher order thoughts that make their (lower order) experiences conscious. The animal having conscious experiences is therefore in a position to do things that animals having unconscious experiences are not. They can, for instance, run from the lion they (consciously) experience--something they might not do by having an unconscious experience of the lion. They can do this because they are (let us say) aware that they are aware of a lion--aware that they are having a lion experience.[7] Animals in which the experience of the lion is unconscious, animals in which there is no higher-order awareness that they are aware of a lion, will not do this (at least not deliberately) This, then, is an advantage of conscious experience; perhaps--who knows?--it is the function of conscious experiences.

I concede the point. But I concede it about ball bearings too. I cannot imagine conscious ball bearings having a function--simply because conscious ball bearings don't do anything non-conscious ball bearings don't do--but I can imagine their being some purpose served by our being aware of ball bearings. If we are aware of them, we can, for instance, point at them, refer to them, talk about them. Perhaps, then, we can replace defective ones, something we wouldn't do if we were not aware of them, and this sounds like a useful thing to do. But this is something we can do by being aware of them, not something they can do by our being aware of them. If a conscious experience was an experience we were aware of, then there would be no difference between conscious and unconscious experiences--anymore than there would be a difference between conscious and unconscious ball bearings. There would simply be a difference in the creatures in whom such experiences occurred, a difference in what they were aware of.

The fact that some people who have cancer are aware of having it while others who have it are not aware of having it does not mean there are two types of cancer--conscious and unconscious cancers. For exactly the same reason, the fact that some people (you and me, for instance) are conscious of having visual and auditory experiences of lions while others (parrots and gazelles, for example) are not, does not mean that there are two sorts of visual and auditory experiences--conscious and unconscious. It just means that we are different from parrots and gazelles. We know things about ourselves that they don't, and it is sometimes useful to know these things. It does not show that what we know about--our conscious experiences--are any different from theirs. We both have experiences--conscious experiences--only we are aware of having them, they are not. Both experiences--those of the gazelle and those of a human--are conscious because, I submit, they make the creature in which they occur aware of things--whatever objects and conditions are perceived (lions, for instance). Being aware that you are having such experiences is as relevant--which is to say, totally irrelevant--to the nature of the experiences one has as it is to the nature of observed ball bearings.[8]

3. The Third Distinction: Object vs. Fact Awareness.

Once again, I expect to hear that this is all too quick. Even if one should grant that conscious states are to be identified with acts, not objects, of creature awareness, the question is not what the evolutionary advantage of perceptual belief is, but what the advantage of perceptual (i.e., phenomenal) experience is. What is the point of having conscious experiences of lions (lion-qualia) as well as conscious beliefs about lions? Why are we aware of objects (lions) as well as various facts about them (that they are lions, that they are headed this way)? After all, in the business of avoiding predators and finding mates, what is important is not experiencing (e.g., seeing, hearing) objects, but knowing certain facts about these objects. What is important is not seeing a hungry lion but knowing (seeing) that it is a lion, hungry, or whatever (with all that this entails about the appropriate response on the part of lion-edible objects). Being aware of (i.e., seeing) hungry lions and being aware of them, simply, as tawny objects or as large shaggy cats (something a two-year old child might do) isn't much use to someone on the lion's dinner menu. It isn't the objects you are aware of, the objects you see--and, therefore, the qualia you experience--that is important in the struggle for survival, it is the facts you are aware of, what you know about what you see. Being aware of (seeing) poisonous mushrooms (these objects) is no help to an animal who is not aware of the fact that they are poisonous. It is the representation of the fact that another animal is a receptive mate, not simply the perception of a receptive mate, that is important in the game of reproduction. As we all know from long experience, it is no trick at all to see sexually willing (or, as the case may be, unwilling) members of the opposite sex. The trick is to see which is which--to know that the willing are willing and the others are not. That is the skill--and it is a cognitive skill, a skill involving knowledge of facts--that gives one a competitive edge in sexual affairs. Good eyesight, a discriminating ear, and a sensitive nose (and the qualia associated with these sense modalities) are of no help in the struggle for survival if such experiences always (or often) yield false beliefs about the objects perceived. It is the conclusions, the beliefs, the knowledge, that is important, not the qualia-laden experiences that normally give rise to such knowledge. So why do we have phenomenal experience of objects as well as beliefs about them? Or, to put the same question differently: Why are we conscious of the objects we have knowledge about?

Still another way of putting this question is to ask why we aren't all, in each sense modality, the equivalent of blindsighters who appear able to get information about nearby objects without experiencing (seeing) the objects.[9] In one way of describing this baffling phenomenon, blindsighters seem able to "see" the facts (at least they receive information about what the facts are--that there is, say, an X (not an O) on the right---without being able to see the objects (the X's) on the right. No qualia. No phenomenal experience. If, therefore, a person can receive the information needed to determine appropriate action without experience, why don't we?[10] Of what use is phenomenal experience in the game of cognition if the job can be done without it?

These are respectable questions. They deserve answers--scientific, not philosophical, answers. But the answers--at least in a preliminary way--would appear to be available. There are a great many important facts that we cannot be made aware of unless we are, via phenomenal experience, made aware of objects these facts are facts about. There are also striking behavioral deficits--e.g., an inability to initiate intentional action with respect to those parts of the world one does not experience (Marcel 1988a). Humphrey (1970, 1972, 1974), worked for many years with a single monkey, Helen, whose capacity for normal vision was destroyed by surgical removal of her entire visual cortex. Although Helen originally gave up even looking at things, she regained certain visual capacities.

She improved so greatly over the next few years that eventually she could move deftly through a room full of obstacles and pick up tiny currants from the floor. She could even reach out and catch a passing fly. Her 3-D spatial vision and her ability to discriminate between objects that differed in size or brightness became almost perfect. (Humphrey 1992: 88).
Nonetheless, after six years she remained unable to identify even those things most familiar to her (e.g., a carrot). She did not recover the ability to recognize shapes or colors. As Humphrey described Helen in 1977 (Humphrey 1992: 89),

She never regained what we--you and I--would call the sensations of sight. I am not suggesting that Helen did not eventually discover that she could after all use her eyes to obtain information about the environment. She was a clever monkey and I have little doubt that , as her training progressed, it began to dawn on her that she was indeed picking up 'visual' information from somewhere--and that her eyes had something to do with it. But I do want to suggest that, even if she did come to realize that she could use her eyes to obtain visual information, she no longer knew how that information came to her: if there was a currant before her eyes she would find that she knew its position but, lacking visual sensation, she no longer saw it as being there. . . . The information she obtained through her eyes was 'pure perceptual knowledge' for which she was aware of no substantiating evidence in the form of visual sensation . . .
If we follow Humphrey and suppose that Helen, though still able to see where objects were (conceptually represent them as there), was unable to see them there, had no (visual) experience of them, we have a suggestion (at least) of what the function of phenomenal experience is: we experience (i.e., see, hear, and smell) them to help in our identification and recognition of them. Remove visual sensations of X and S might still be able to tell where X is, but S will not be able to tell what X is. Helen couldn't. That is--or may be--a reasonable empirical conjecture for the purpose of experience--for why animals (including humans) are, via perceptual experience, made aware of objects. It seems to be the only way--or at least a way--of being made aware of pertinent facts about them.

Despite the attention generated by dissociation phenomena, it remains clear that people afflicted with these syndromes are always "deeply disabled" (Weiskrantz 1991: 8). Unlike Helen, human patients never recover their vision to anything like the same degree that the monkey did. Though they do much better than they "should" be able to do, they are still not very good Humphrey (1992: 89). Blindsight subjects cannot avoid bumping into lamp-posts, even if they can guess their presence or absence in a forced-choice situation. Furthermore,

All these subjects lack the ability to think about or to image the objects that they can respond to in another mode, or to inter-relate them in space and in time; and this deficiency can be crippling (Weiskrantz, 1991: 8).
This being so, there seems to be no real empirical problem about the function (or at least a function) of phenomenal experience. The function of experience, the reason animals are conscious of objects and their properties, is to enable them to do all those things that those who do not have it cannot do. This is a great deal indeed. If we assume (as it seems clear from these studies we have a right to assume) that there are many things people with experience can do that people without experience cannot do, then that is a perfectly good answer to questions about what the function of experience is. That is why we, and a great many other animals, are conscious of things and, thus, why, on an act conception of state consciousness, we have conscious experiences. Maybe something else besides experience would enable us to do the same things, but this would not show that experience didn't have a function. All it would show is that there was more than one way to skin a cat--more than one way to get the job done. It would not show that the mechanism that did the job wasn't good for something.


Davies, M. and G. W. Humphreys (1993). Introduction. In Davies and Humphreys (1993), eds. Consciousness. Oxford; Blackwell, 1-39.

Dretske, F. (1993). Conscious experience. Mind, vol 102.406, 1-21.

Dretske, F. (1995). Naturalizing the Mind. Cambridge, Ma.; MIT Press, A Bradford Book.

Humphrey, N. (1970). What the frog's eye tells the monkey's brain. Brain, Beh. Evol, 3: 324-37.

Humphrey, N. (1972). Seeing and nothingness. New Scientist 53: 682-4.

Humphrey, N. (1974). Vision in a monkey without striate cortex: a case study. Perception 3: 241-55.

Humphrey, N. (1992). A History of the Mind: Evolution and the Birth of Consciousness. New York: Simon and Schuster.

Milner, A. D. (1992). Disorders of perceptual awareness-- commentary. In Milner & Rugg (1992), 139-158.

Milner, A. D. & M. D. Rugg, eds. (1992). The Neuropsychology of Consciousness. London: Academic Press.

Rosenthal, D. (1990). A theory of consciousness. Report No. 40,Research Group on Mind and Brain, ZiF, University of Bielefeld.

Rosenthal, D. (1991). The independence of consciousness and sensory quality. In Villanueva 1991, 15-36.

Rey, G. (1988). A question about consciousness, in H. Otto and J.Tuedio, eds., Perspectives on Mind. Dordrecht: Reidel.

van Gulick, R. (1985). Conscious wants and self awareness. The Behavioral and Brain Sciences, 8.4, 555-556.

van Gulick, R. (1989). What difference does consciousness make? Philosophical Topics, 17: 211-30.

Velmans, M. (1991). Is human information processing conscious? Behavioral and Brain Sciences 14.4,651-668.

Villanueva, E., ed. (1991). Consciousness. Atascadero, CA; Ridgeview Publishing Co.

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White, A. R. (1964). Attention. Oxford: Basil Blackwell

Weiskrantz, L., ed. (1986). Blindsight: A Case Study and Implications. Oxford: Oxford University Press.

Weiskrantz, L. (1991). Introduction: Dissociated Issues. In Milner and Rugg (1991): 1-10.


1. There is a sense in which it enables me to do things I would not otherwise be able to do--e.g., bequeath my books to my nephews and nieces--but this, clearly, is a constitutive, not a causal, sense of "enable." Spelling out this difference in a precise way is difficult. I will not try to do it. I'm not sure I can. I hope the intuitive distinction will be enough for my purposes.

2. For recent expressions of interest, see Velmans 1991, Rey 1988, and Van Gulick 1989.

3. I here ignore dispositional senses of the relevant terms--the sense in which we say of someone or something that it is a conscious being even if, at the time we describe it this way, it is not (in any occurrent sense) conscious. So, for example, in the dispositional sense, I am a conscious being even during dreamless sleep.

4. I here ignore disputes about whether, in some strict sense, we are really aware of objects or only (in smell) odors emanating from them or (in hearing) voices or noises they make. I shall always take the perceptual object--what it is we see, hear, or smell (if there is such an object)--to be some external physical object or condition. I will not be concerned with just what object or condition this is.

5. In saying this I assume two things, both of which strike me as reasonably obvious: (1) to be aware that you are aware of a french horn requires some understanding of what awareness is (not to mention an understanding of what a french horn is); and (2) mice (even if we give them some understanding of french horns) do not understand what awareness is (they do not have this concept).

6. This is not to say that consciousness is always advantageous. As Georges Rey reminds me, some tasks--playing the piano, pronouncing language, and playing sports--are best performed when the agent is largely unaware of the performatory details. Nonetheless, even when one is unconscious of the means, consciousness of the end (e.g., the basket into which one is trying to put the ball, the net into which one is trying to hit the puck, the teammate to whom one is trying to throw the ball) is essential. You don't have to be aware of just how you manage to backhand the shot to do it skillfully, but, if you are going to be successful in backhanding the puck into the net, you have to be aware of where the net is.

7. I assume here that, according to HOT theories, the higher order thought one has about a lion experience that makes that experience conscious is that it is a lion experience (an experience of a lion). This needn't be so (Rosenthal 1991denies that it is so), but if it isn't so, it is even harder to see what the good of conscious experiences might be. What good would be a thought about a lion experience that it was . . . what? . . . a (generic) experience?

8. I'm skipping over a difficulty that I should at least acknowledge here. There are a variety of mental states--urges, desires, intentions, purposes, etc.--which we speak of as conscious (and unconscious) whose consciousness cannot be analyzed in terms of their being acts (instead of objects ) of awareness since, unlike the sensory states associated with perceptual awareness (seeing, hearing, and smelling), they are not, or do not seem to be, states of awareness. If these states are conscious, they seem to be made so by being objects, not acts of consciousness (see, e.g., Van Gulick 1985). I don't here have the space to discuss this alleged difference with the care it deserves. I nonetheless acknowledge its relevance to my present thesis by restricting my claims about state-consciousness to experiences--more particularly, perceptual experiences. Whatever it is that makes a desire for an apple, or an intention to eat one, conscious, experiences of apples are made conscious not by the creature in whom they occur being conscious of them, but by making the creature in whom they occur conscious (of apples).

9. For more on blindsight see Weiskrantz 1986 and Milner & Rugg 1992. I here assume that a subject's (professed) absence of visual experience is tantamount to a claim that they cannot see objects, that they have no visual experience. The question that blindsight raises is why one has to see objects (or anything else, for that matter) in order to see facts pertaining to those objects--what (who, where, etc.) they are. If blindsighters can see where an object is, the fact that it is there (where they point), without seeing it (the object at which they point), what purpose is served by seeing it?

10. There are a good many reflexive "sensings" (Walker 1983: 240) that involve no awareness of the stimulus that is controlling behavior--e.g., accommodation of the lens of the eye to objects at different distances, reactions of the digestive system to internal forms of stimulation, direction of gaze toward peripherally seen objects. Milner (1992:143) suggests that these "perceptions" are probably accomplished by the same midbrain visuomotor systems as mediate prey catching in frogs and orienting reactions in rats and monkeys. What is puzzling about blindsight is not that we get information we are not aware of (these reflexive sensings are all instances of that), but that in the case of blindsight one appears able to use this information in the control and guidance of deliberate, intentional, action (when put in certain forced choice situations)--the sort of action which normally requires awareness.