I.3 Kinds of Consciousness

In case 1, I certainly see the sidewalk ahead as I walk home, and I react accordingly. If this were not the case, I would bump into things or end up in the street. But I am not con­scious of my perceptions. I am not aware of how things look to me on the sidewalk and road. I am distracted.

The kind of consciousness the absence of which this case illustrates is that of introspective awareness. It is sometimes held that this sort of consciousness is solely a matter of its subject having a higher-order thought that he or she is undergoing a certain mental state, where this thought is not based on inference or observation (Rosenthal 1997). Another view is that introspective awareness, at least in the case of experiences and feelings, is a kind of secondary seeing-that or displaced perception (Dretske 1995; Tye 1995a, 2000). I shall have more to say about this view in chapter 1. A third view is that introspective awareness is a kind of monitoring of mental states much like perception via the senses but inwardly directed (Lycan 1997). For present purposes, it is not necessary to adjudicate between these accounts.

Let us call the above kind of consciousness "introspective consciousness" or "Т-consciousness" for short, however it is further analyzed. A distracted walker, then, has no /-consciousness of his visual perceptions.

The cases of the bird-watcher and the wine taster (cases 2 and 3) illustrate what I shall call "discriminatory (or D-) consciousness." The bird-watcher who is conscious of the bird has successfully picked it out cognitively from the branches and foliage in its immediate vicinity. Likewise, the wine taster who becomes conscious of certain differences in wines of which he was, earlier in his training, unconscious has noticed those differences. D-consciousness is a form of percep­tual consciousness—a form that involves recognition of what is perceived.

The party animal (case 9) lacks discriminatory conscious­ness with respect to anything external. He is not processing information about the external world and responding to it in a rational manner. Let us say that the general sort of con­sciousness lacked by the party animal is "responsive con­sciousness," or "R-consciousness" for short. This sort of consciousness, I might add, can be partial: A person who is limited in his reactions upon opening his eyes in the morn­ing after taking a heavy sleeping draught the night before is not fully R-conscious. There is much around him that he does not notice. R-consciousness, then, is a generalized ver­sion of D-consciousness.

In case 4—the brief encounter—you see eighteen books, but, for some of the books, you are not conscious of your see­ing them. This is an absence of /-consciousness. You also lack D-consciousness with respect to some of the books, since there are books you do not notice.

In case 5, you have a headache of which you sometimes are not conscious. This again is the absence of /-consciousness, as is the following case of the pain that wakes you in the night. These two cases, however, strongly suggest another kind of consciousness not yet distinguished. If you have a headache then you have a pain. And, intuitively, to have a pain is to undergo a certain sort of feeling. In case 5, then, there is a feeling without /-consciousness, and likewise in case 6 (the pain in the night) at least prior to waking up. But if there is a feeling, then there must be consciousness, in some sense of the term. For how could a feeling be a feeling and yet not be conscious at all?

Call this sort of consciousness "phenomenal (or P-) con­sciousness." A mental state may be said to be P-conscious if, and only if, it has a phenomenal character (or a subjective "feel"). Thus, a pain of which its subject is not /-conscious is nonetheless P-conscious. Via /-consciousness, the subject comes to know what it is like to have the pain, but what the pain itself is like—its phenomenal "feel"—is not a matter of /-consciousness.

Exactly the same sort of situation obtains in case 8. There is nothing incoherent in supposing that something looks blue to me even though, owing to a distraction, I do not think or judge that it looks blue (or that it is blue).⁵ But if the wall before my eyes looks blue then I must be having a visual experience of blue. And if I am having a visual experience of blue, then I am in a conscious state representing blue. There is some phenomenal character to my visual state as I view the blue wall. Of course, if my mind is wandering, I will not be conscious (in the introspective sense) of this phenomenal char­acter. But the wall, by hypothesis, continues to look blue. Had I introspected at the time at which my mind was wandering, I would have been aware that I was continuing to have a visual experience of blue. But I did not, in fact, then intro­spect. There is P-consciousness without /-consciousness.

Suppose that on the wall in the center of my field of view there is an insect. Initially I notice the insect, but, as my mind wanders, for a moment or two I fail to notice it. Intuitively, I still see it, even though briefly I do not see that it is on the wall before me. But if I see the insect, it must look some way to me;⁶ and if it looks some way to me, it pro­duces in me a conscious state. This state is P-conscious, but I am not D-conscious of the insect.

P-consciousness is integral to experiences and feelings generally, as is noted in case 7. Wherever there is a feeling or experience, there must be P-consciousness, some phenome­nology that the relevant state has.

P-consciousness is often illustrated further by reference to the famous inverted and absent qualia hypotheses.⁷ The for­mer of these hypotheses, for the case of color, is the claim that there might be someone whose color experiences are phenomenally inverted relative to those of others even though she uses color words and functions in color tests in all the standard ways. Here there is a phenomenal differ­ence, that is, a difference in phenomenal consciousness, that is not manifested in any behavioral or functional differ­ences. The latter hypothesis is the claim that there might be someone who felt or experienced nothing at all, someone who altogether lacked P-conscious states, but who func­tioned in just the same manner as someone who underwent such states.

It is also in connection with P-consciousness that the sug­gestion arises that there is a huge explanatory gap. Physical changes in the gray and white matter composing our brains produce states that can be fully understood only by crea­tures that share our experiential perspective, states that have a "technicolor phenomenology" (as McGinn puts it in his 1991). There seems an immense gap here, something that cries out for explanation. Why does a given firing pattern generate a given feeling instead of a different one? Why does that firing pattern produce any felt quality or subjec­tive phenomenology at all? How can a state like pain, whose nature cannot be fully comprehended by someone who has never experienced it, be generated by objective, physical processes in the brain—processes whose nature is accessible from many points of view?

P-consciousness, it should be noted, is a feature of mental states. I-, D-, and R-consciousness are different: they are properties of creatures. They are all forms of creature con­sciousness. Are they also forms of consciousness that could be present in a zombie, that is, a being who functionally is just like a sentient creature but who lacks any phenomenal consciousness? That depends. On one natural view of D- and R-consciousness, they are purely cognitive activities that are normally based on P-consciousness without inher­ently requiring it. In the case of I-consciousness, the relevant issue is whether introspection is necessarily accompanied by an inner phenomenology. However this is settled, a crea­ture cannot be conscious in any of the three ways distin­guished unless it undergoes mental states having conceptual contents that play a role in reasoning and the intentional con­trol of behavior. Such states are sometimes said to be access conscious (Block 1993; also this vol., chap. 5, p. 123). If zom­bies are conceivable, then access consciousness can conceiv­ably occur without phenomenal consciousness.

Returning now to the adumbrated cases, we should note that P-consciousness is also present indirectly in case 4. Ex hypothesi, you see all the books. So, each book (briefly) looks some way to you as your eyes move along the shelf. In having visual experiences of books that you do not notice, you are subject to a kind of visual consciousness. There is thus something it is like for you at each moment as your eyes scan the contents of the shelf. What it is like changes, even if you are not introspecting and you are not cognizant of all the changes. Your visual experiences are phenome­nally conscious.⁸

There is one complication worth mentioning here. Perhaps in some cases the act of introspection itself causally impacts the phenomenal character of the introspected state, so that what it is like to undergo the state then changes with the act of introspection. For example, suppose I have a toothache that persists all evening. There are times at which I am not conscious of it. At other times, I am conscious of it and I attend carefully to how it feels. Perhaps the act of attention changes to some extent the phenomenal character of the toothache. That at least seems conceivable. If so, then the attended phenomenal character is different from the unattended one.

In case 10 (the dreamer), my experiences are P-conscious. There is something it is like for me in dreaming of the ptero­dactyl. But I am not R-conscious. I am not processing infor­mation about the external world and responding to it in a rational manner. So, there is nothing real with respect to which I am D-conscious. Need there be /-consciousness? If I wake up in a panic, to some significant degree I must believe that I am in a situation that is dangerous to me. But I need not believe or think that I am having a visual experi­ence as of a pterodactyl, even if I do believe that I am being pursued by a pterodactyl. So long as the latter belief is pre­sent, it will cause in me fright. The former belief or thought, which is higher-order and hence more complicated content- wise, is not necessary. So, at least on accounts of introspec­tion that require such a higher-order state, /-consciousness need not be present.

This conclusion is reinforced by case 11. It seems to me plausible to suppose that dogs that growl during REM sleep are subject to P-conscious states that cause beliefs about things in the world or people (for example, a coveted bone or a postman). But it seems much less plausible to suppose that in each and every such case, a higher-order belief or thought must be present. Surely, one important difference between humans and other animals is that the former are much more reflective than the latter. There is certainly P-consciousness, however. It would be absurd to suppose that there is nothing it is like for a dog that chews a favorite bone or prefers chopped liver for its dinner over anything else it is offered.

Case 12 is similar to case 11. Although I am hallucinating, I am still undergoing sensations and perceptual experiences. My experiential states are P-conscious: there is something it is like for me as I feel afraid, as I seem to smell a strange odor, and as I seem to see a white shape. But in this case I am also R-conscious. For I am awake and cognitively process­ing information from my surroundings.

Of the kinds of consciousness illustrated by the above exam­ples, by far and away the most problematic is P-consciousness; for it is in connection with P-consciousness that the really difficult philosophical puzzles and conundrums arise. It is also in connection with P-consciousness that the sort of unity that will concern us in this book is found.