Skepticism and the Mind-Body Problem
It is sometimes illuminating to compare disparate areas of philosophy in order to find shared patterns, e.g., ethics and mathematics. I will do the same with respect to skepticism and the mind-body problem. These two problems have a similar structure and arise from similar origins, surprising as that may seem. We can start with the role of consciousness in generating the problems, because it is at the heart of both of them. We are accustomed to this idea in the case of the mind-body problem: it is consciousness, in particular, that gives rise to the classic mind-body problem. Consciousness presents itself as remote from the body and brain—as a different kind of phenomenon altogether. It seems separable from the brain, only contingently connected to it, a thing apart. Hence intimations of dualism: dualism is the metaphysical view that consciousness itself encourages us to adopt. We certainly don’t experience consciousness as a brain state—no neural facts rise to the level of conscious awareness. Consciousness is not consciousness of the brain qua material object. Thus, consciousness is problematically related to the brain, not its natural accompaniment (like the skull). The link is opaque, inscrutable, apparently contingent. We can’t infer one from the other: there is an “explanatory gap”. One is not deducible from the other—hence the (apparent) possibility of zombies and disembodied minds. Without consciousness the mind-body problem would be less severe, maybe not a philosophical problem at all (we don’t have a mind-body problem for plants, bacteria, and insentient worms). So much, so familiar. But what is not familiar is the role of consciousness in generating skepticism, particularly about the external world. Without consciousness the skeptical problem is scarcely formulable at all, especially in its most intuitive form. For the problem is precisely that our consciousness, as given, fails to entail the world in which we naturally believe: how things consciously seem to us with regard to external reality does not necessarily determine how things actually are. Things could seem a certain way, consciously, but not be that way—there is no entailment, no logical bridge. There is an “epistemological gap”: the relation is apparently contingent from the perspective of lived consciousness. Nothing in (perceptual) consciousness provides a sure route from itself to the reality beyond—thus, the possibility of hallucination, the evil demon, the brain in a vat, the Matrix. We can’t look into our consciousness and see what the external world is really like; it certainly isn’t merely consciousness itself. Consciousness and reality are things apart, contingently connected, logically independent—or so it seems to us. Consciousness gives us an impression of contingency with regard to external reality—that reality might not even be there. It is easy for us to imagine our consciousness existing but without any reality beyond it. Solipsism is a naturally available possibility, given what we know of consciousness: this consciousness could exist without that world. Consciousness advertises itself as autonomous, distinct, separable, compatible with many hypotheses about the world beyond. Skepticism then results from these intimations, because it trades on contingency as between consciousness and the world in which we uncritically believe (take for granted). Are you now seeing the structural similarity I alluded to? Doesn’t it stick out like a sore thumb? In both cases consciousness gives rise to impressions of autonomy, independence, contingency; and it does so distinctively, as part of its specific nature. It seems autonomous, cut off. In both cases it appears too distant from what it should be closely connected to—the brain or the external world. The gap is the problem, and consciousness itself produces the sense of a gap—it insists on it. No consciousness, no gap. Consciousness seems compatible with a variety of types of underlying stuff, not just the familiar brain stuff; and also compatible with a variety of external states of affairs, not just the ones we normally assume. It gives rise to “intuitions of compatibility”.
Clearly, we need to lessen the gap, or close it completely; and historically, that is what has been attempted. The array of options is similar in the two cases. We can bring consciousness closer to the brain, and we can bring it closer to external reality. There are two ways of doing this: make consciousness closer to its assumed correlate, or make the correlate closer to consciousness. You know the drill: behaviorism and physicalism, or idealism and panpsychism, in the case of the mind-body problem; and externalism or phenomenalism in the case of the skeptical problem. Thus: consciousness is more like the brain than we tend to suppose, or the brain is more like consciousness; and the mind is more bound up with the external world than has been supposed, or the world is more mental than people tend to think. Accordingly, we have an array of “solutions” to the two problems, more or less reductive: the mind is really the brain or the brain is really the mind, on the one hand; and the mind is really the external world or the external world is really the mind, on the other. These are gap-closing moves, designed to overcome the apparent autonomy of consciousness, and hence the problems this autonomy creates. There is no dualism of mind and brain, and no dualism of mind and external world. Alternatively, it might be suggested that elimination is the way to go: no mind, or no brain; and no mind, or no external world. If there is no such thing as mind, there is no problem about its relation to the brain; and if there is no such thing as knowledge, there is nothing that fails to connect logically to external reality. Likewise, if we get rid of brains and material objects, by embracing idealism, we don’t have to worry about relating the mental to the material. Or we might take a less arduous route: declare miracles and the futility of seeking explanations—God is the supernatural fulcrum in which it all turns. He sets up a pre-established harmony between mind and brain, and he ensures that our beliefs never stray far from the truth. There is nothing further to be said: the needed necessities are God-given and brute. God is no deceiver and he has installed the miraculous pineal gland to connect mind and body—end of story.
My point is that the two problems are strikingly similar; I am not out to endorse any of the solutions just outlined (I would reject them all). But let me try to drive the point home by describing a couple of far-out thought experiments; then I will suggest a possible solution applicable to both cases (this is where things get sticky). First, consider a conscious being whose knowledge of the external world is limited to his own brain: he knows about this material object but no other (don’t ask me how this came about). Then, the domain of this being’s knowledge is confined to the basis of his own mental states: his problematic relations concern the same entity. His knowledge of his brain is subject to skepticism, and his mind is subject to the usual mind-body problem. He is problematically related in two ways to the same thing, viz. his brain. The two problems coincide extensionally. Maybe what solves one might solve the other, or provide clues to a solution? He has two sorts of mind-brain problem, in effect. Now let’s get even more wildly counterfactual: suppose there is a conscious being whose brain encompasses all of the reality he knows about—it is enormously extended in space. His brain extends way beyond his head, taking in all that he knows (and maybe more). Then, the skeptical problem coincides with the mind-body problem for this being: he doesn’t really have knowledge of the world beyond his consciousness, and there is the problem of explaining the relation between his mind and his (enormous) brain. The two relations, epistemological and ontological, coincide extensionally. The problems thus overlap, despite being distinct problems. Wouldn’t we then expect to find some overlap in their solution? The same kind of solution applies to both cases, the problems being so similar. But what is that solution?
I made a point of saying that consciousness presents itself as autonomous, but it doesn’t follow that it isautonomous. Impressions (“intuitions”) of autonomy might be illusions of autonomy. This is a familiar line of thought for the mind-body relation: it might seem contingent but not really be so. The reason for this could be that the grounds of the underlying necessity are opaque to us. I won’t go into the details of this proposal here; what I want to suggest is that something similar might hold in the skepticism case. This is not an easy question, partly because we are not entirely clear what knowledge requires in the way of justification. Let me make the initial observation that it is unlikely that millions of years of evolution would leave it entirely accidental that experience matches reality. It may seem to us that our consciousness could have sprung into existence yesterday, but in reality it is the result of countless interactions with the environment stretching back millions of years. It is conditioned and shaped by this long history of involvement in the physical world—the body and the world beyond. This body and brain couldn’t exist without that evolutionary background, and neither could the associated mind. The causal history of both is integral to their identity, which is not to say that it is written into the surface of things. Consciousness couldn’t be what it is without this causal-explanatory relation to external reality. So, it is possible that facts about this history underpin a necessary relation to external reality sufficient to ground knowledge; for all we know, knowledge might be more grounded than we suppose. When we think we are imagining our consciousness without the corresponding reality, we might be under an illusion—this is simply not (metaphysically) possible. But we don’t see why this is so. In other words, knowledge might be a mystery: we just don’t know what grounds knowledge, and hence refutes the skeptic. Likewise, we don’t know what refutes the dualist; we just know that dualism has to be false (dualism in the sense that the mind could exist without the body and brain). That is, we can go mysterian about knowledge. We have already gone mysterian about the mind in relation to the brain; let’s also go mysterian about knowledge in relation to external reality. Thus, we deal with the skeptical problem as we dealt with the mind-body problem, which is what we might expect given their structural similarity. Both problems arise from consciousness-as-we-apprehend-it, so the solution to both might have the same form. Or perhaps I shouldn’t say “solution”; rather, the answer to both problems is that we labor under deep ignorance of what makes consciousness realized in the brain and also directed towards objective reality. It is in the brain and it does enable us to know the external world, but how this is so we don’t comprehend. We fail to appreciate this because consciousness gives us the strong impression that it is autonomous and hence separable from the brain and from the external world. It invitesdualism and skepticism, but we can decline the invitation, preferring instead to acknowledge ignorance. We have “inadequate ideas” about consciousness, so we are tempted by dualism and skepticism—both resulting from impressions of autonomy. But really, objectively, consciousness cannot float free of the brain or become detached from the world that formed it. Both problems arise because consciousness isn’t self-revealing; it doesn’t display its real nature—its place in nature. It seems to stand apart from nature, but it can’t really do that. The image I have is that consciousness is just another node in a tight web of interconnected natural facts; it can’t be plucked out of this web, any more than any other natural object can. The web includes the brain and the external world, to which consciousness is inextricably linked. It is thus some kind of necessary truth that consciousness exists in the brain and indicates external reality more or less correctly. Solipsism cannot be true, even though it seems metaphysically possible. Thus, radical skepticism is false and so is extreme dualism: both assume detachments that are not naturally possible. It is as if the mind is the brain and knowledge is the world, though these formulations are obscure at best (literally false at worst). Maybe we need a new “is”. My knowledge is not really separable from what it is knowledge of, as my mind is not really separable from my brain. My mind reaches out to the world as it reaches out to my brain, though I have no clear conception of what this involves. My mind isn’t over here while my brain and external reality are over there. They cannot be pulled apart. But my consciousness gives me the distinct impression that it stands aloof and apart from everything else. It makes me think I live in a double world, whereas in fact I live in a single interconnected world. The answer to both problems is that consciousness is not as autonomous as it seems.[1]
[1] I could have written many footnotes to this paper, hedging, qualifying, diluting, but I decided not to. It needs to be stated as baldly as possible. You need the big picture, sharply outlined, not footling footnotes. Think of it as having virtual footnotes.