An Argument Against Idealism

Imagine we lived in a world in which idealism was the dominant philosophy (in fact, it is the actual world, but that’s another story). The prevailing doctrine is that everything that exists is mental, i.e., a state of consciousness. Not just the mind itself but also the so-called physical world—mountains, molecules, the brain. All these things consist of ideas in the mind, specifically sense experiences of certain kinds—for example, episodes of seeing the thing in question. To be a brain, say, is to be a sense experience as of a brain. Physical objects are really collections of sense-data, as the terminology has it. These sense-data may exist in the human mind or God’s mind or just in my mind (solipsistic idealism]. Physical objects are reducible to such mental entities; this is their essence, their mode of being. Everything has a mental nature.

But suppose there is opposition to such a doctrine: some people firmly believe, eccentrically, that some things are inherently not conscious states; their essence is to be not-conscious, mind-independent. Their battle-cry is, “The not-conscious world is what makes idealism metaphysically impossible”. They reject the claim that physical objects are reducible to sense experiences. The idealists wonder what else these objects could be: it would have to be something unknown, of an unfamiliar nature, a mysterious substance of some sort, subject to skepticism. It would have to be something there is nothing it is like to be, but what would that be? Everything we really know is like something—visual experiences, pains, etc. They have trouble getting their minds around this supposed non-mental reality: how can we even think of it? However, the anti-idealists have an argument that they believe can break this stalemate of intuitions and settle the question once and for all. It is quite an ingenious argument, centering on a conceptual claim. They point out that everything conscious is such that there is something it is like to be it: therefore, it is only possible to grasp a given type of mind by sharing it. You only know what it is like to be a human by having human experiences—it can’t be done from no “point of view”. It takes one to know one; you can’t (fully) know what is like to be a bat because you aren’t one. This property of consciousness they call subjectivity: you can only form a concept of another’s mental state if you are a subject similar to the other subjectively—if you are mental birds of a feather, so to speak. But this is not true of physical states: these you can grasp even if you don’t share them—you don’t need to be a mountain to know what a mountain is; you don’t need to share a bat’s brain to know what a bat’s brain is. In short, no point of view is built into physical concepts: they can be grasped from any point of view. You can do physics if you are human, Martian, or Vulcan—or any species with the requisite intelligence. You can do geometry even if you are not yourself similarly geometrical; you don’t need to be Euclidian in order to understand Euclidian geometry, say. The physical may be defined as whatever there is nothing it is like to be, so there is no like that you must share in order to grasp it. But then, it is not possible to reduce the physical to the mental, because these are concepts of a different order, denoting properties of different kinds. It would not be possible, say, to reduce the physical brain to sensations as of brains, because such sensations would embody a distinctive subjective quality graspable only by beings that have similar sensations; but that is not true of the brain itself, because that can be grasped by beings with arbitrarily different types of sensations. Thus, there must be more to reality than is contained in sensations of reality—the physical cannot be the mental. Physical things are essentially objective: they can be grasped from many points of view and therefore cannot be subjective in nature. Things there is nothing it’s like to be cannot be reduced to things there is something it’s like to be. Therefore, idealism must be false: it tries to explain the objective in terms of the subjective. It cannot be an accurate account of things that lack consciousness, precisely because it explains everything in terms ofconsciousness. The body cannot be explained in terms of the mind, on pain of subjectivizing the body.

Clearly, this argument parallels a familiar argument against reducing the mind to the body; it simply reverses that argument. If the familiar argument is valid, then so is this one. Thus, that argument defeats bothmaterialism and idealism in one fell swoop. It can be used against Hobbes but also against Berkeley. It can be used against physical anti-realism as much as against reductive physicalism. Basically, the argument is that a color-blind man cannot understand color vision but he can understand the brain science of color vision (and the rest of physics). For if he could not, the brain would not be a physical object, which it is. The objective cannot be reduced to the subjective, as the subjective cannot be reduced to the objective. The view from somewhere cannot be reduced to the view from nowhere, and the view from nowhere cannot be reduced to the view from somewhere.[1]

[1] Is this argument perhaps just a little bit too powerful?

On “What is it Like to be a Bat?”

Thomas Nagel’s great paper “What is it Like to be a Bat?” begins resoundingly enough: “Consciousness is what makes the mind-body problem really intractable. Perhaps this is why current discussions of the problem give it little attention or get it obviously wrong.” These words slip smoothly off the tongue and make an impression. They have certainly been influential. The paper itself can be credibly credited with beginning the current craze for consciousness studies (I am part of that craze myself). However, I have come to believe that they are massively misleading and in fact completely wrong (!). This doesn’t detract from the cogency of the main argument of the paper, since it can be otherwise formulated; but it does affect the correct interpretation of that argument and its relevance to consciousness. In short, I don’t think the argument has much to do with consciousness as such, however we choose to interpret that word. I am well aware that these are heretical statements, so I propose to take it slowly and carefully. We must pay strict attention to the language.

When Nagel says that consciousness is what makes the mind-body problem really intractable we must take him to be contrasting the attribute of consciousness with other possible candidates for centrality. What might these be? He doesn’t say, so we must fill in the gap; these other attributes of the mind are supposed less intractable. He doesn’t claim they are not intractable at all; he implies that they are not really intractable—notas intractable as consciousness. It is consciousness that provides the severest form of intractability. I think we may presume that what he has in mind, or would mention if pressed, are such attributes as intentionality, privacy, invisibility, privileged access, infallibility, freedom, indivisibility, and unity—anything philosophers have supposed to characterize the mind distinctively. It is the fact that the mind is conscious that really puts the cat among the pigeons—makes the mind-body problem deep and hard. Presumably, then, the unconscious is not among the things that make the problem especially intractable. There are, according to Nagel, a number of aspects of the mind that pose mind-body problems, some of them quite intractable, but none as intractable as consciousness: it is the nub, the heart, the nerve. Thus, we need to address it specifically: we need to ask what it is about consciousness that makes it so hellishly problematic. Then we will see the true magnitude of the mind-body problem, and also understand why materialists steer clear of mentioning it—for they see the extreme difficulties it poses for their program.

The first question we must ask is what Nagel means by “consciousness”. This is not at all obvious initially, because that word and its cognates have different uses and definitions. One might be forgiven for not knowing exactly what Nagel means by “consciousness” in his opening line. He does, however, quickly step in to clarify the matter by employing the phrase “what it is like”: to be conscious is for there to be something it is like for the creature in question (bat or human). As he later acknowledged, he got the phrase from Brian Farrell and Timothy Sprigge, though it is now strongly associated with him. It certainly has a ring and pungency to it (a meme waiting to happen). There are questions about whether all conscious states have the property in question,[1] but Nagel focuses on perceptual sensations in the body of the paper, so we need not be concerned about its general applicability—except to note that some instances of consciousness may not be problematic in virtue of having the designated property. At any rate, sensations have it paradigmatically. Whether what it’s likeness really serves to define consciousness in general is a moot question; what matters is that some mental states have it and raise questions discussed in the paper. It becomes the operative notion as the paper proceeds. We need not mention consciousness explicitly again; we can stick to the property picked out by the phrase in question. It turns out, then, that the issue concerns this property in relation to perceptual sensations, particularly those of bats when they echolocate. Whether this property is really necessary and sufficient for consciousness is beside the point; the problems will still arise even if it is neither (as some have contended). The arguments go through just as well without talking a firm stand on the issue, though it is heuristically helpful to link the notion to consciousness. But then the talk of consciousness is playing no integral role in the argument. This is good in a way, because we wouldn’t want those arguments to depend on a dubious definition of consciousness (as devotees of higher-order thought theories have suggested). We can detach the two questions. This is also helpful if we wish to extend the argument to unconscious mental states: for it seems questionable that unconscious mental states are perfectly tractable, or more tractable than consciousness. The underlying problem concerns sensations, conscious or unconscious; that’s what the paper is really about (it could have been called “Echolocation Sensations and the Mind-Body Problem”). It is what it’s likeness that is really intractable for materialists—what Nagel later calls subjectivity. For this property can only be grasped by people who share the property, unlike physical properties. But then talk of consciousness drops out—and so does consciousness itself if we reject the definition Nagel offers. The whole issue can be formulated without even using the word “consciousness” or any synonym. The crux of the problem, according to Nagel, is the epistemic subjectivity (self-centeredness) of the property of what it’s likeness; what this has to do with consciousness can be left open. You can be a complete skeptic about consciousness, an eliminativist, and still accept Nagel’s argument; or you could be a higher-order thought theorist; or a self-ascriptive speech act theorist; or an electrical brain wave theorist—you would still have to contend with the point that there is something it is like to be a sensation, and hence a self-centeredness to mental concepts not matched by physical concepts. To put it bluntly, the argument really has nothing to do with consciousness; the concept is not essential to it. The first sentence of the paper could have been “Sentience is what makes the mind-body problem really intractable”, given that the argument will concern perceptual sensations—though we would need to define “sentience” so as to include pre- or sub-conscious perceptions if they also can only be grasped by sharing the perceptions of the other.[2]

Why did contemporary theorists avoid talk of consciousness in their defenses of materialism? Is it because they sensed trouble lurking there, as Nagel suggests, or might it be that they found it hard to give a precise meaning to the word (is being awake that much of a problem?)? Perhaps they thought it was best understood as self-ascription of psychological predicates, in which case they felt they already had that under their belt. Maybe there was no evasiveness, just confidence that they had it tamed. The problems concerned the actual features of mental states (e.g., intentionality) not whether people were conscious of them. So, I doubt intellectual dishonesty was at the root of their neglect. They might indeed have been mightily impressed with Nagel’s basic argument, but just doubtful about what it had to do with consciousness as they understood it (“self-perception” or some such). The concept of consciousness plays no real role in Nagel’s argument and invites irrelevant objections (“I don’t agree with your definition of consciousness”). What is true is that what it’s likeness is linguistically awkward, perhaps conceptually awkward, so that we have no ready term to use when mounting arguments about the denoted property. Thus, we latch onto “consciousness” as a convenient shorthand; but the dictionary provides no such definition[3] of the term and it is vulnerable to attack for obscurity and indeterminacy of extension (do memories have it?). The whole topic is a linguistic mess, frankly. It therefore thrives on buzzwords and scare quotes. The issues are real but the language is sloppy and inadequate.

I have talked about the first two lines of Nagel’s classic paper, but what about the title? It too gives a misleading impression, though it is obviously catchy. Many people seem to think it is about the problem of other minds; it isn’t. It’s about the mind-body problem and the prospects for physical reduction. But we would certainly be within our rights to observe that it is not about what it’s like to be a bat, or for any animal to be the animal it is; it is about what certain sensations are like, and are. We know what it’s like to be a bat in many respects, but that isn’t the question; the question is whether we can grasp the concept of echolocation experiences given that we can’t echolocate. It isn’t about understanding other animals—a worthwhile endeavor—it’s about our concepts of experience and their dependence on our own specific “point of view”. I’m not criticizing Nagel for giving his paper the title he did—a title is just a title—but careless readers might easily get the wrong idea. Calling it “Can We Know What Echolocation Experiences are Like?” would be more accurate, if less memorable.

Have we been barking up the wrong tree in pursuing “consciousness studies”? It might be said that the points I have raised are merely verbal; we all know what we mean and our talk of consciousness can always be paraphrased away in terms of subjectivity and what it’s likeness. There is much truth in this sanguine assessment, but it is alarming that we have been carried away in recent years by sloppy language and lazy thinking (I include myself). The word “consciousness” has become a sexy meme, a type of profundity-signaling, a form of advertisement. Nagel’s words had more power than he knew.[4]

[1] Suppose I am conscious that I am late for a meeting: is there something it is like to be in this mental state that is common and peculiar to all instances of it? Won’t different memories and emotions go through the minds of different people in the same state? And is this what it is to be conscious you are late? How is what it’s like related to the propositional content of such a conscious state? The notion is infuriatingly vague and elusive when applied generally.

[2] Perhaps it would be better to say that there are several attributes of the mind that create difficult, even intractable, mind-body problems, drawn from the list I gave; consciousness is one of them. There are many mind-body problems not a single problem focused on consciousness (whatever we choose to mean by that word). Nagel put one neglected problem on the map (epistemic egocentricity, to give it a name), but then the map became too dominated by this problem, now grandly called the problem of consciousness.

[3] The OED gives “aware of and responding to one’s environment” for “conscious”; no mention of what it’s likeness. Clearly, there is no synonymy here.

[4] One often hears people talking about the wonderful new subject of “human consciousness”, as if psychology and philosophy have at last come to grips with what matters to all of us—our own lives and experiences. This is obviously completely wrong. It isn’t all warm and fuzzy and humanistic; it’s about whether animal experiences can be reduced to brain processes—a very old and quite dusty academic subject. The mind-body problem isn’t about getting yourself off the sofa to clean up the kitchen when you really don’t feel like it.

An Even Harder Problem

People like to talk about “the hard problem”, meaning the problem of consciousness. The phrase itself invites scrutiny: it contains the definite article and thus implies uniqueness, unlike “a hard problem”; and “hard” is an attributive adjective associated with cognate words, i.e., “harder” and “hardest”. So, we must ask: is the problem the only hard problem, and what problems is it harder than. I am concerned here with whether there are any problems that are harder than it: it may be hard but that doesn’t imply that no problems are harder; it might be, logically, that many problems are harder. It would then not be the hard problem singular, but just ahard problem among other hard problems, some of which are even harder. It might even be an easy problem compared to these, and certainly not harder than they are. In a ranking of problems, it might be somewhere in the middle—harder than some, easier than others. The really hard problems might sniff snootily at it and call it a doddle or other nasty names. It might even be terminal for human minds but still not that hard in the broader scheme of things that includes problems not soluble by any conceivable form of intelligence. If it turned out that the majority of problems were harder than this problem, it would be semantically correct to call it “an easy problem”, because to be a hard problem it would need to be harder than most problems, and it isn’t. The phrase itself begs many questions and may not be very helpful in the long run.

What other problems might be deemed hard problems? Many problems are hard relative to the capacities of chosen types of intelligence; they are all hard relative to some. Hardness is a relational characteristic, being an epistemic notion in its current use. For us humans now, we can list a bunch of notoriously difficult problems: the origins of space and time, the nature of gravity, the origins of life, the possibility of free will, the biological point of dreams, the workings of creativity, the nature of mathematical knowledge, the grounds of ethical judgment. What, by contrast, are the easy problems? I suppose we could list many of the problems of astronomy, physics, chemistry, and biology: the structure of the solar system (heliocentric), the basic laws of mechanics (Newtonian), the chemical composition of water (H2O), the origin of species (Darwinian). These problems have been solved and are thus ipso facto easy, unlike the list of so-called hard problems. In the case of evolution, we might even say that the problem is intrinsically easy, though it took a long time to hit upon it: it’s just a matter of differential selection applied to antecedent species (see Darwin’s Origin of Species). Our question must be: are any of the hard problems harder than the problem of consciousness?

There is one feature of the problem of consciousness that stands out: we know what it is. We have, as the old philosophers used to say, an “adequate conception” of it, a “clear and distinct idea”. We are indeed intimately acquainted with consciousness, nothing more so, since we live with it every day. We don’t say “Consciousness, what is that?” (compare dark matter, or even electricity). We don’t know consciousness just by its effects, or merely structurally, or purely functionally; we know it intrinsically, personally, as it actually is. It is therefore surprising that we are also so ignorant about it: you would think it would be an easy problem! You would think we would say, “Oh consciousness, yeah, I know all about that, it’s just XYZ”. You would think its relation the brain, which we also know about directly, would be perfectly transparent, intelligible, and long since figured out. But it isn’t so. The continuing puzzlement is itself puzzling. The point I want to make here is that the fact of direct knowledge suggests that other problems might be harder simply because we have no direct knowledge of their subject matter. Take the case of causation: ever since Hume we have accepted that causation is deeply puzzling, a mystery to the human mind. We believe in it but we don’t see it: we have no impression of the necessary connection in which causation consists; we don’t know its inner nature. We are acquainted with constant conjunction and individual events but not with the causal glue that binds them. The case is precisely unlike the case of consciousness, with which we are intimately acquainted. This puts causation on a different level from consciousness: we are not even in the know about what it is—we just have a word for we-know-not-what. This might well make the problem of causation harder than the problem of consciousness in the end; at least we can test theories of consciousness against our ordinary knowledge of its nature, which is what we can’t do with respect to causation. How could we verify or falsify a theory of causation? We perceive consciousness in ourselves whereas we don’t perceive causation anywhere.

I am softening you up for the really interesting case, which I hesitate to unveil. Is there anything about the mind that is also unseen and unperceived but which raises similar problems to consciousness? Is there anything that stands to consciousness as dark matter stands to matter? If so, it might well present the same problems as consciousness and then some—it would be an even harder problem. Would it be the hardest problem of all? That would be a bold and reckless conjecture, but it might well be a lot harder than the problem of consciousness—it might be really really f***ing hard. The question is worth asking, even if it is impossible to deliver a definitive answer. I am thinking, of course, of the unconscious—of the part of the mind that lies beyond the reach of introspection.[1] We might call it the “unknown mind”—the mind that is merely postulated not perceived, hidden not apparent. What are its characteristics? We don’t know—it’s hidden from introspective knowledge—but we can responsibly speculate. It is mental after all. First, it must surely have intentionality: be about things other than itself, representational, symbolic. Second, it must be similar to the consciousness with which it interacts and which it parallels; it may even slide into consciousness occasionally. Take unconscious perception: sub-threshold perceptions of color, say, must have a nature similar to supra-threshold perceptions. That is, they must have a phenomenology; there must be something it is like for them to exist—though we are not consciously aware of it. Aren’t pains we are not currently aware of also pains? Suppose this is so: the unconscious mind is both intentional and phenomenological. Then we can say that it has these characteristics without benefit of conscious awareness of them (as dark matter is presumably extended, though not visibly so). So, it is unlike consciousness in not being a datum of awareness; we are not directly acquainted with it. Yet it presents much the same explanatory problems as consciousness without such direct awareness. We have no “adequate conception” of it, knowing it only by inference, structurally, functionally. We really don’t know what we are talking about. So, the hardness of the problem is multiplied: it has the problems of intentionality and phenomenology but without our having any real grasp of the subject matter of the problems. This makes it harder than the hard problem of consciousness; the unconscious is the really hard problem of the mind. Sure, consciousness is hard (a lot harder than evolution), but it isn’t uniquely hard (that “the”), and it isn’t even the hardest of the hard problems concerning the mind. The not conscious mind is arguably harder, more recalcitrant. In linguistics finding an adequate grammar of conscious language is pretty damn hard, but discovering the grammar of the unconscious aspect of our language is even harder, because it is hidden away in the unconscious part of the mind. What is the generative grammar of the unconscious language of thought? That is a problem even harder. When the mind operates unconsciously it becomes even harder to understand than when it is open to view.

And what is the hardest problem of all? I don’t know. We have quite a few to choose from. The problem of consciousness is hard (harder than many problems); the problem of the unconscious is harder still (arguably): but what problem puts these to shame in the competition for supreme hardness? My money is on the origins of space and time, because I have absolutely no idea where you might even begin with this problem (or pair of problems); they certainly didn’t evolve from earlier species of space and time, or from bubble gum, or from God stuff. I don’t even think we have much idea about what they are. It’s a hard problem what the hardest problem is, but probably not the hardest problem.[2]

[1] I write about this in “The Mystery of the Unconscious” in Philosophical Provocations (2017).

[2] I think “the hard problem” is a phrase that appeals to people who don’t know much philosophy, or much science for that matter. Philosophy is full of hard problems (compared to animal husbandry, say) and science also faces many unsolved problems. It is hardly illuminating or informative to call the problem of free will or the problem of skepticism “hard problems”—of course they are, they have been around for thousands of years. They are hardly “easy problems” compared to other problems already solved. The phrase is more of a meme than an insight. It is an outright banality—junk thought. People think they are being profound when they say it; in reality, it is platitudinous at best.