In the case of experience, on the other hand, the connection with 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?[44]
We appear to be faced with a general difficulty about psychophysical reduction. In other areas the process of reduction is a move in the direction of greater objectivity, toward a more accurate 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 apparatus, 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 objective 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 referring 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 substitute an objective concept of mind for the real thing, in order to have nothing left over which cannot be reduced. If we acknowledge that a physical theory of mind must account for the subjective 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,[45] 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 hypothesis 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. Per haps 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 which physical states and events they are, but that should not prevent us from undo standing 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 X is Y we know how it is supposed to be true, but that depends on a conceptual or theoretical background and is not conveyed by the “is” alone. We know how both “X” and “Y” 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.
44
The problem is not just that when I look at the Mona Lisa, my visual experience has a certain quality, no trace of which is to be found by someone looking into my brain. For even if he did observe there a tiny image of the Mona Lisa, he would have no reason to identify it with the experience.
45
The relation would therefore not be a contingent one, like that of a cause and its distinct effect. It would be necessarily true that a certain physical state felt a certain way. Kripke (1972) argues that causal behaviorist and related analyses of the mental fail because they construe, for example, “pain” as a merely contingent name of pains. The subjective character of an experience (“its immediate phenomenological quality,” Kripke calls it [p. 340]) is the essential property left out by such analyses, and the one in virtue of which it is, necessarily, the experience it is. My view is closely related to his. Like Kripke, I find the hypothesis that a certain brain state should
A theory that explained how the mind-brain relation was necessary would still leave us with Kripke’s problem of explaining why it nevertheless appears contingent. That difficult seems to me surmountable, in the following way. We may imagine something by representing it to ourselves either perceptually, sympathetically, or symbolically. I shall not try to say how symbolic imagination works, but part of what happens in the other two cases is this. To imagine something perceptually, we put ourselves in a conscious state resembling the state we would be in if we perceived it. To imagine something sympathetically, we put ourselves in a conscious state resembling the thing itself. (This method can be used only to imagine mental events and states—our own or another’s.) When we try to imagine a mental state occurring without its associated brain state, we first sympathetically imagine the occurrence of the mental state: that is, we put ourselves into a state that resembles it mentally. At the same time, we attempt perceptually to imagine the nonoccurrence of the associated physical state, by putting ourselves into another state unconnected with the first: one resembling that which we would be in if we perceived the nonoccurrence of the physical state. Where the imagination of physical features is perceptual and the imagination of mental features is sympathetic, it appears to us that we can imagine any experience occurring without its associated brain state, and vice versa. The relation between them will appear contingent even if it is necessary, because of the independence of the disparate types of imagination.
(Solipsism, incidentally, results if one misinterprets sympathetic imagination as if it worked like perceptual imagination: It then seems impossible to imagine any experience that is not one’s own.)