we can never describe or understand is the crudest form of cogni- tive dissonance. This brings us to the edge of a topic that requires much more discussion than I can give it here: namely, the relation between facts on the one hand and conceptual schemes or systems of repre- sentation on the other. My realism about the subjective domain in all its forms implies a belief in the existence of facts beyond the reach of human concepts. Certainly it is possible for a human being to believe that there are facts which humans never mi// possess the requisite concepts to represent or comprehend. Indeed, it would be foolish to doubt this, given the finiteness of humanity's expectations. After all, there would have been transfinite numbers even if everyone had been wiped out by the Black Death before Cantor discovered them. But one might also believe that there are facts which could not ever be represented or comprehended by human beings, even if the species lasted forever—simply because our structure does not permit us to operate with concepts of the requisite type. This impossibility might even be observed by other beings, but it is not clear that the existence of such beings, or the possibility of their existence, is a precondition of the significance of the hypothesis that there are humanly inaccessible facts. (After all, the nature of beings with access to humanly inacccssible facts is presumably itself a humanly inaccessible fact.) Reflection on what it is like to be a bat seems to lead us, therefore, to the conclusion that there are facts that do not consist in the truth of propositions expressi Ale in a human language. We can be compelled to recognize the existence of such facts without being able to state or comprehend them. I shall not pursue this subject, however. Its bearing on the topic before us (namely, the mind-body problem) is that it enables us to make a general observation about the subjective character of experience. Whatever may be the status of facts about what it is like to be a human being, or a bat, or a Martian, these appear to be facts that embody a particular point of view. I am not adverting here to the alleged privacy of experience to its possessor. The point of view in question is not one accessi- ble only to a single individual. Rather it is a fy;br. It is often possible to take up a point of view other than one's own, so the comprehension of such facts is not limited to one's own case. There is a sense in which phenomenological facts are perfectly objective: one person can know or say of another what the quality of the other's experience is. They are subjective, however, in the sense that even this objective ascription of experience is possible only for someone sufficiently similar to the object of ascription to be able to adopt his point of view—to understand the ascrip- tion in the first person as well as in the third, so to speak. The more different from oneself the other experiencer is, the less success one can expect with this enterprise. In our own case we occupy the relevant point of view, but we will have as much difficulty understanding our own experience properly if we approach it from another point of view as we would if we tried to understand the experience of another species without taking up its point of view.

This bears directly on the mind-body problem. For if the facts of experience—facts about what it is like for the experiencing organism—are accessible only from one point of view, then it is a mystery how the true character of experiences could be revealed in the physical operation of that organism. The latter is a domain of objective facts par eyre//ence—the kind that can be observed and understood from many points of view and by individuals with differing perceptual systems. There are no comparable imaginative obstacles to the acquisition of knowledge about bat neurophysiol- ogy by human scientists, and intelligent bats or Martians might learn more about the human brain than we ever will.

This is not by itself an argument against reduction. A Martian scientist with no understanding of visual perception could under- stand the rainbow, or lightning, or clouds as physical phenomena, though he would never be able to understand the human con- cepts of rainbow, lightning, or cloud, or the place these things occupy in our phenomenal world. The objective nature of the things picked out by these concepts could be apprehended by him because, al'hough the concepts themselves are connected with a particular point of view and a particular visual phenome- nology, the things apprehended from that point of view are not: they are observable from the point of view but external to it; hence they can be comprehended from other points of view also, either by the same organisms or by others. Lightning has an objective character that is not exhausted by its visual appearance, and this can be investigated by a Martian without vision. To be precise, it has a more objective character than is revealed in its visual appearance. In speaking of the move from subjective to objective characterization, I wish to remain noncommittal about the existence of an end point, the completely objective intrinsic nature of the thing, which one might or might not be able to reach. It may be more accurate to think of objectivity as a direc- tion in which the understanding can travel. And in understanding a phenomenon like lightning, it is legitimate to go as far away as one can from a strictly human viewpoint.•

In the case of experience, on the other hand, the connection with a particular point of view seems much closer. It is difficult to understand what could be meant by the objective character of an experience, apart from the particular point of view from which its subject apprehends it. After all, what would be left of what it was like to be a bat if one removed the viewpoint of the bat ? But if experience does not have, in addition to its subjective character, an objective nature that can be apprehended from many different points of view, then how can it be supposed that a Martian investigating my brain might be observing physical processes which were my mental processes (as he might observe physical processes which were bolts of lightning), only from a different point of view ? How, for that matter, could a human physiologist observe them from another point of view ?10

We appear to be faced with a general difficulty about psycho- physical reduction. In other areas the process of reduction is a move in the direction of greater objectivity, toward a more accu- rate view of the real nature of things. This is accomplished by reducing our dependence on individual or species-specific points of view toward the object of investigation. We describe it not in terms of the impressions it makes on our senses, but in terms of its more general effects and of properties detectable by means other than the human senses. The less it depends on a specifically human viewpoint, the more objective is our description. It is possible to follow this path because although the concepts and ideas we employ in thinking about the external world are initially applied from a point of view that involves our perceptual appa- ratus, they are used by us to refer to things beyond themselves— toward which we have the phenomenal point of view. Therefore we can abandon it in favor of another, and still be thinking about the same things.

Experience itself, however, does not seem to fit the pattern. The idea of moving from appearance to reality seems to make no sense here. What is the analogue in this case to pursuing a more objective understanding of the same phenomena by abandoning the initial subjective viewpoint toward them in favor of another that is more objective but concerns the same thing ? Certainly it appears unlikely that we will get closer to the real nature of human experience by leaving behind the particularity of our human point of view and striving for a description in terms accessible to beings that could not imagine what it was like to be us. If the subjective character of experience is fully comprehensible only from one point of view, then any shift to greater objectivity —that is, less attachment to a specific viewpoint—does not take us nearer to the real nature of the phenomenon: it takes us farther away from it.

In a sense, the seeds of this objection to the reducibility of experience are already detectable in successful cases of reduction ; for in discovering sound to be, in reality, a wave phenomenon in air or other media, we leave behind one viewpoint to take up another, and the auditory, human or animal viewpoint that we leave behind remains unreduced. Members of radically different species may both understand the same physical events in objec- tive terms, and this does not require that they understand the phenomenal forms in which those events appear to the senses of members of the other species. Thus it is a condition of their refer- ring to a common reality that their more particular viewpoints are not part of the common reality that they both apprehend. The reduction can succeed only if the species-specific viewpoint is omitted from what is to be reduced.

But while we are right to leave this point of view aside in seeking a fuller understanding of the external world, we cannot ignore it permanently, since it is the essence of the internal world, and not merely a point of view on it. Most of the neobehaviorism of recent philosophical psychology results from the effort to sub- stitute an objective concept of mind for the real thing, in order to have nothing left over which cannot be reduced. If we acknowl- edge that a physical theory of mind must account for the sub- jective character Of experience, we must admit that no presently available conception gives us a clue how this could be done. The problem is unique. If mental processes are indeed physical processes, then there is something it is like, intrinsically," to undergo certain physical processes. What it is for such a thing to be the case remains a mystery.

What moral should be drawn from these reflections, and what should be done next? It would be a mistake to conclude that physicalism must be false. Nothing is proved by the inadequacy of physicalist hypotheses that assume a faulty objective analysis of mind. It would be truer to say that physicalism is a position we cannot understand because we do not at present have any conception of how it might be true. Perhaps it will be thought unreasonable to require such a conception as a condition of understanding. After all, it might be said, the meaning of physicalism is clear enough: mental states are states of the body; mental events are physical events. We do not know in/zirh physical states and events they are, but that should not prevent us from understanding the hypothesis. What could be clearer than the words “is” and “are” ?

But I believe it is precisely this apparent clarity of the word “is” that is deceptive. Usually, when we are told that A is I we know how it is supposed to be true, but that depends on a concep- tual or theoretical background and is not conveyed by the “is” alone. We know how both “A” and “F” refer, and the kinds of things to which they refer, and we have a rough idea how the two referential paths might converge on a single thing, be it an object, a person, a process, an event, or whatever. But when the two terms of the identification are very disparate it may not be so clear how it could be true. We may not have even a rough idea of how the two referential paths could converge, or what kind of things they might converge on, and a theoretical framework may have to be supplied to enable us to understand this. Without the framework, an air of mysticism surrounds the identification.

This explains the magical flavor of popular presentations of fundamental scientific discoveries, given out as propositions to which one must subscribe without really understanding them. For example, people are now told at an early age that all matter is really energy. But despite the fact that they know what “is” means, most of them never form a conception of what makes this claim true, because they lack the theoretical background. At the present time the status of physicalism is similar to that which the hypothesis that matter is energy would have had if uttered by a pre-Socratic philosopher. We do not have the be- ginnings of a conception of how it might be true. In order to understand the hypothesis that a mental event is a physical event, we require more than an understanding of the word “is.” The idea of how a mental and a physical term might refer to the same thing is lacking, and the usual analogies with theoretical iden- tification in other fields fail to supply it. They fail because if we construe the reference of mental terms to physical events on the usual model, we either get a reappearance of separate subjective events as the effects through which mental reference to physical events is secured, or else we get a false account of how mental terms refer (for example, a causal behaviorist one). Strangely enough, we may have evidence for the truth of some- thing we cannot really understand. Suppose a caterpillar is locked in a sterile safe by someone unfamiliar with insect metamorphosis, and weeks later the safe is reopened, revealing a butterfly. If the person knows that the safe has been shut the whole time, he has reason to believe that the butterfly is or was once the caterpillar, without having any idea in what sense this might be so. (One possibility is that the caterpillar contained a tiny winged parasite that devoured it and grew into the butterfly.)

It is conceivable that we are in such a position with regard to physicalism. Donald Davidson has argued that if mental events have physical causes and effects, they must have physical de- scriptions. He holds that we have reason to believe this even though we do not—and in fact would not—have a general psychophysical theory.'° His argument applies to intentional mental events, but I think we also have some reason to believe that sensations are physical processes, without being in a position to understand how. Davidson's position is that certain physical events have irreduc- ibly mental properties, and perhaps some view describable in this way is correct. But nothing of which we can now form a con- ception corresponds to it; nor have we any idea what a theory would be like that enabled us to conceive of it.'°

Very little work has been done on the basic question (from which mention of the brain can be entirely omitted) whether any sense can be made of experiences’ having an objective character at all. Does it make sense, in other words, to ask what my experi- ences are really like, as opposed to how they appear to me ? We cannot genuinely understand the hypothesis that their nature is captured in a physical description unless we uńderstand the more fundamental idea that they have an objective nature (or that ob- jective processes can have a subjective nature) .14

I should like to close with a speculative proposal. It may be possible to approach the gap between subjective and objective from another direction. Setting aside temporarily the relation between the mind and the brain, we can pursue a more objective understanding of the mental in its own right. At present we are completely unequipped to think about the subjective character of experience without relying on the imagination—without taking up the point of view of the experiential subject. This should be regarded as a challenge to form new concepts and devise a new method—an objective phenomenology not dependent on em- pathy or the imagination. Though presumably it would not cap- ture everything, its goal would be to describe, at least in part, the subjective character of experiences in a form comprehensible to beings incapable of having those experiences.

We would have to develop such a phenomenology to describe the sonar experiences of bats; but it would also be possible to begin with humans. One might try, for example, to develop con- cepts that could be used to explain to a person blind from birth what it was like to see. One would reach a blank wall eventually, but it should be possible to devise a method of expressing in ob- jective terms much more than we can at present, and with much greater precision. The loose intermodal analogies—for example, “Red is like the sound of a trumpet”—which crop up in dis- cussions of this subject are of little use. That should be clear to anyone who has both heard a trumpet and seen red. But struc- tural features of perception might be more accessible to objective description, even though something would be left out. And con- cepts alternative to those we learn in the first person may enable us to arrive at a kind of understanding even of our own experience which is denied us by the very ease of description and lack of distance that subjective concepts afford.

of experience to assume a more intelligible form. Aspects of sub- jective experience that admitted this kind of objective description might be better candidates for objective explanations of a more familiar sort. But whether or not this guess is correct, it seems unlikely that any physical theory of mind can be contemplated until more thought has been given to the general problem of sub- jective and objective. Otherwise we cannot even pose the mind- body problem without sidestepping it.'^