A Puzzle Regarding Color

Color has long intrigued philosophers and others. Is it objective or subjective, or something in between? Is an inverted spectrum possible? What is the nature of logical truths about color? I will raise a different question: do things have the colors they have contingently or necessarily? Is color arbitrary or grounded in facts of nature? For example, could the sky have been green and plants blue? Could blood have been yellow, snow black, coal white, the earth red? I mean by this could things have looked that way; I am not concerned with whether objects could have had different reflectance properties. Things look a certain way color-wise to humans and other animals, but could they just as easily have looked a different way? Is it like driving on the right: could we just as easily have driven on the left (as some other countries do)? Is it completely contingent what colors we bathe the world in? Or is it that specific colors naturally belong to some things and could not be changed without some sort of loss or disruption? If we saw plants not as green but as blue or red or yellow, would there be any loss of accuracy or utility? Are plants naturally seen as green—is this the color they ought to be seen as? I think we are confronted by conflicting intuitions on this question: on the one hand, we feel that plants are correctly seen as green; on the other, there would be no error in seeing them as a different color. Thus, if Martians inverted our color perceptions, they could not be convicted of error or perversity or sub-optimality—they would be as right as we are. The reason is that each color presents the same range of variations and hence distinctions: the same visual information can be presented in blue as in green—and that is all that matters (biologically, intellectually). The color itself is just an arbitrary label, like a proper name. The function of color perception is to allow for visual discrimination, but this can be achieved in a variety of ways; perceivers are not tied down to one color. It would be a form of color prejudice to insist that seeing plants as green is the only viable and veridical way of seeing them; blue would do just as well. Seeing blood as yellow is just as reasonable as seeing it as red. And yet we observe that no such variation obtains: as far we can tell, all animals see the colors of objects the same way, i.e., plants as green and blood as red. The color receptors in the eyes are universal in seeing creatures on Earth: but this seems surprising from an evolutionary perspective, since it would have been just as sensible to evolve blue perception for plants as green perception. We find variation in which side of the road people drive on, which is only to be expected given that this is entirely arbitrary; but we find no variation in what colors are attributed to the world despite the apparent arbitrariness of a given selection. Why? That is the puzzle: why is it theoretically feasible to invert colors and yet this doesn’t happen? Moreover, why does it feel wrong to see plants as anything other than green? Why is seeing plants as green universal and intuitively appropriate, while logically it could have been otherwise without loss or error? Something has to give.

It may be said that this is a case of simple prejudice—custom, what we are used to. We have always seen plants as green and blood as red, so we mistakenly think there is something necessary about this; we are like people who think that driving on the right is the God-given correct way of driving. We have a color superiority complex (prejudiced Martians would have the opposite prejudice). Alternatively, evolution just happened to make an arbitrary choice millions of years ago and has seen no reason to change its mind, even locally. It could have chosen blue or red for plants, but it settled on green and has stuck in its ways. I think neither of these views is plausible: there is something more deep-seated about the way color is perceived. But it is hard to discern what it is exactly—nothing immediately suggests itself. To put it crudely, plants really are green, so it is preferable to see them that way. Compare: it is really better to drive on the right, because actually the sun is less blinding that way. But what is this hidden factor? Could it be that green is actually better suited to encoding subtle differences in things than blue? That would appear to be true of black and white, but on the face of it blue admits of the same degree of variation as green. Is it that things would be more confusing if plants were blue given that the sky is blue—animals would see no sharp distinction? But then why not see the sky as green by way of contrast? Why is blue better for the sky than green? Both can vary in degree of lightness; both can allow clouds to be equally visible. It would be different if we asked why the sky isn’t seen as bright red, because then it would be more limited in its potential variations. So, the puzzle remains: every color seems as good as any other from an informational point of view. Nor does it seem any harder for the brain to produce blue than green perceptions; the colors are equally available and equipotential. Nothing in nature favors one over the other—and yet nature seems determined to stick with a single color-scheme. It is as if it wants animals to see plants as green, even though it has no reason to want that. The colors seem functionally identical, but nature sticks religiously to one scheme rather than another, puzzlingly.

Perhaps we are looking in the wrong place—the informational powers of color perception. What about the emotional and pragmatic connotations of color—the psychology of color? For it does seem true that colors vary in their psychological associations—and not just by habit or custom. Green really is a soothing restful peaceful color, while red is not. Yellow is a joyful light-hearted color. Blue is an attractive charming color (blue eyes). Black is a doom-laden sinister color. White is an optimistic open color. Why this is, we don’t know; it just is. There is a psychology of color—affective, even moral. Orange is felt to be tacky and in poor taste; brown is rather blah. We have favorite colors and least favorite colors. We are not indifferent to color, as if it is nothing but a neutral medium for conveying information. Nature wants us to have good feelings about plants, so it makes us see them as green. Why? Because we have to live with them every day, eat them, lie down on them, or up them. Nature needs to make them a color we are not put off by; it needs to make our brain receptive to them. In the case of blood, it needs to make us wake up and take notice, because the sight of blood is a bad sign. Thus, the colors of nature are designed to mesh with our emotions, desires, and practical decisions—to be psychologically right. Nature (evolution) is cunning in this way: it designs animals to be the best they can be in the circumstances—the most efficient, survival-oriented. All this is carefully planned: the plant world is bathed in green because that is what works best psychologically. Green is inherently likeable, even loveable, so evolution sees to it that we see plants as green. Of course, this is rather mysterious: how can a color be inherently emotional (compare shapes)? And yet it appears to be so: we are hardwired to react to green in certain ways that are conducive to survival, because green intrinsically has a certain affective character. Colors have logical relations built into them, but they also have psychological dispositions built into them. Neither of these things is easy to understand, but they appear to be facts: green is essentially affect-positive, and in a specific way. Not scintillating perhaps (unlike blue) but easy on the eye and brain; not attention-grabbing but mellow and relaxing. When we see green, as with a country landscape, our soul breathes a sigh of relief, a feeling of security and tranquility—unlike a blaze of red flowers or a gorgeously blue sky (too much uplift). The painter chooses his colors carefully, aware of their affective potential; nature chooses its color palette with equal care, properly sensitive to the needs and desires of the creatures living within it. It just wouldn’t feel right to see plants as blue or red, even if this would entail no loss of informational content—it would send the wrong emotional message. Likewise, the bright red of blood delivers a message of alarm and danger—act now! Red is the color of emergency; green of contentment; blue of transcendence (heaven above, piercing blue eyes). Colors are actually very clever, ingeniously designed, magically effective. Natural selection knew what it was doing when it selected the colors of the rainbow, right down to the last detail. Colors are carefully designed adaptive devices not merely dispensable means of conveying objective information. They are not bland. Thus, they are not arbitrarily assigned and interchangeable.

How many colors are there? Estimates vary: I would say basically four: blue, green, red, and yellow (plus black and white). We are told that some animals see colors we don’t see. Let’s say there are ten basic colors on planet Earth. But how many logically possible colors are there—a hundred, a million, infinitely many? Let’s say a lot. Then evolution selected a small subset from the full range, presumably because these are the best ones given the conditions on Earth. They are assigned to objects according to criteria involving psychological requirements (as well as informational requirements). We can assume that this choice was well-motivated—these are the optimal colors for evolutionary purposes. It wasn’t haphazard, random, arbitrary. We thus have a carefully curated world of colors to feast our eyes on (good metaphor)—the best of the best. We should feel good about this: our eyes and brains are recipients of the finest class of colors that money can by—the Rolls-Royces of colors. When you see green you are seeing a finely crafted chromatic machine lovingly perfected over millions of years. You should feel privileged to be privy to such a marvelous spectacle, to live with it day in and day out. Aesthetically speaking, our colors are probably the most beautiful of all (it’s nice to think so anyway); they are not second-rate goods selected by a careless middle man. And each belongs in its proper place. Our visual world is a lot more resplendent and fine-tuned than we might have supposed. We should be thankful.[1]

[1] I almost want to say that colors are a minor miracle—but perhaps I should say that they are major (natural) miracle. They are wonders of the world, demigods, great works of art. We have no idea how they came to be, from what they evolved; but they are with us all the time, glowing like so much pale fire. They came into existence many billions of years after the big bang, themselves flaring into being, and entered the minds of terrestrial creatures. Whenever you see a color, you are seeing a miracle of nature, a veritable show-stopper. I am surprised they have never been used to prove the existence of God! They are much more miraculous than the standard biblical miracles, and we can witness them all the time just by opening our eyes (again, I am speaking of perceived color not the physical basis of color in objects.) They have a kind of intelligence. They evolved but have never gone extinct (that we know of), thus demonstrating their adaptive value. They have helped many a species live to fight another day.

Abstract (and Other) Objects

I propose to discuss an incredibly difficult question and to suggest an incredible answer to it—an answer that only ineluctable logic could recommend to our modern sensibility. It concerns the threefold distinction between the physical, the mental, and the abstract. Let’s first try to get the abstract in our sights (this is hard enough), starting with the OED: the adjective “abstract” is defined as “theoretical rather than physical or concrete”, and “derived, extracted”. Thus, the abstract is defined by contrast with the physical or concrete, and implies an operation of derivation or extraction. We may gloss this as: “derived or extracted from something physical or concrete”. This corresponds with the idea of abstraction as a mental act—the abstract is what is derived byintellectual abstraction. It is thus something secondary, dependent—both ontologically and epistemically. The abstract object depends for its existence and nature on the concrete object from which it is an abstraction, and we acquire the concept of the abstract object by a mental act of abstraction. For example, the number 2 depends on the (concrete) objects so numbered, and we have the concept 2 by a mental act of abstraction (derivation, extraction). This is clearly not the notion of the abstract entertained by Pythagoras and Plato (and Frege and Godel); they viewed abstract objects as primary existences—as more real than concrete perceptible objects, or at least equally real. If anything, Pythagoras and Plato viewed the concrete as dependent on the abstract, ontologically and epistemically. And there have been plenty of mathematicians who would endorse this picture—for them, mathematical objects are directly apprehended and depend for their existence on nothing else. So, the dictionary definition is quite wrong as far they are concerned; or rather, they would demur from describing numbers etc. as “abstract” in the dictionary sense. They would choose to describe them in other terms—as Plato described them as Forms. In truth, it is hard to find satisfactory language for the doctrine in question—quite possibly because the conception is hard to pin down. The concept tends to be defined negatively, by contrast with “physical” or “mental”. If we imagine alien thinkers who are natural-born Pythagorean Platonists, but shaky on the mental and the physical, we might suppose them to have a robust ontology of the “abstract” (while not using that term), and only negative definitions of the mental and physical (what is not what mathematical objects are). In any case, our definition of the abstract would not be natural to them, and is conceptually lacking in our own case. But let’s suppose such entities to exist in whatever sense Pythagoras and Plato supposed, as autonomous, independent constituents of reality, even if we find it difficult to get a conceptual-linguistic handle on them. What, then, about the other two categories—are they properly defined?

Here the situation is not much better than with the concept of the abstract: neither concept is clearly defined. The concept of the “physical” is hopelessly undefined; this is a familiar story that I won’t repeat. The OED gives us “relating to the body as opposed to the mind”. That is about the best we are going to get, but everything hangs on the word “mind”: do pain and other bodily sensations relate to the mind or the body? Surely, the body, but they are usually classified as mental by theorists. What about the senses, particularly touch? The body, of course. Thought relates to the mind, but most of what we habitually call “mental” today does not. I would say that all of the mind relates to the body, particularly the brain, as opposed to some supposed immaterial entity (the “soul”); so, the mind is all physical, according to the dictionary. So be it: let the mind be physical in that sense—the distinction then vanishes. Nor is the concept of the mental well-defined: are character traits mental, or the unconscious, or skills, or language? There is no “criterion of the mental”. Both concepts are ill-defined, virtually meaningless. I think they should be abandoned in theoretical taxonomic contexts; they are obsolete holdovers from religious doctrines of the soul and immortality. The body and brain have various kinds of attributes—that’s all we need to say.[1] From the point of view of nature, no deep ontological division exists; there is no natural kind consisting of all and only (so-called) mental things. Nor is there a natural kind of (so-called) physical things. We could instead speak simply of organic and inorganic and give up on the (metaphysical) mental-physical distinction. This is a Spinoza-like position: the body has the power to produce all the attributes we and other animals possess, including consciousness—there is just one substance. It is also Darwinian: everything evolves by natural selection acting on the body. There is no separate soul, no supernatural basis for the mind. Accordingly, the traditional threefold distinction is defective beyond repair: each concept is deeply flawed and should not be used to shape our considered ontology. We need a new taxonomic scheme.

So, what would the new and improved ontology look like? Granted we accept the reality of mathematical objects, it will be a dualist ontology: Forms and Bodies, basically. We will have geometry and arithmetic on the one hand and organic and inorganic bodies on the other. Simplifying, we have material things and immaterial things—Forms not being material. Spinoza plus Plato. There is no Cartesian dualism, but there is a Platonic dualism. There is no Mind-Body dualism, but there is a Body-Form dualism. This means that the problems of dualism will carry over to the new dualism: how exactly are the two spheres of reality related? We can envisage a familiar array of options: attempts to reduce one sphere to the other, eliminative positions, and interaction problems (Plato was already aware of these). The two realms have quite different natures (they are different metaphysical natural kinds) yet they come together, because mathematics applies to the natural world. None of this means that the so-called mind-body problem will disappear; but it does mean that we cannot frame it in the post-Cartesian (pre-Darwinian) style. Trying to conceptualize this new dualism will not be easy, because we don’t have concepts naturally suited to the task, particularly concepts of the “abstract”. There is much here that is “wide open and extremely confusing”.[2] Bodies are spatiotemporal but Forms are not; bodies change and evolve but not Forms; bodies can be perceived via the senses but Forms cannot. Could we get by with an ontology of bodies and sets of bodies? Can our current conceptual scheme take the strain? Could there be a deeper unity that encompasses both? Could bodies have tiny Forms in them that combine to create larger Forms (“pan-Formism”)? Are some things intrinsically more mathematical than others? Are bodies appearances of Forms? Is it possible to be an idealist about Forms? Is the philosophy of mathematics really the most basic area of philosophy (the “mathematical turn”)? Is the concept of body inescapably anthropocentric? Is the Body-Form problem soluble? Is there anything it’s like to be a number?[3]Does the brain have a hidden mathematical essence? And so on.[4]

[1] We can certainly raise questions about the relation between these attributes (say, consciousness and neural states), but we won’t be treating these attributes as “mental” in some inclusive sense (Wittgenstein would approve).

[2] I am quoting Kripke.

[3] This may seem like a wild question, but is it any wilder than asking the same question about atoms? If numbers are real constituents of reality that enter into bodily facts (including facts about conscious experience), then we can envisage a metaphysics that seriously ponders the question.

[4] Much of metaphysics has centered around the relation between the “mental” and the “physical”, poorly defined as those words are (religion surely comes into this). According to the new dispensation, Plato’s metaphysics replaces this preoccupation: we really should be concerned with the relation between the Formal (mathematical, logical, moral, aesthetic, universal) and the Bodily (spatial, perceptible, concrete, evolving, particular). It won’t be easy to make this switch. This is why I said that the answer I am sketching is incredible (to us, now). But these are early days. Who knows what philosophical convulsions might lie in wait for us?

How Not to Talk Garbage

There is a new type of speech act in the marketplace—the talking of garbage. Philosophers and others have identified several species of defective speech act: falsehood, lies, nonsense, bullshit, hate speech, etc. Each of these needs careful study, and has received it. But speech garbage is in a class of its own, and it is on the rise. What is it? The first point is that it is not easy to say; this allows it to pass unnoticed and to prosper. Roughly, it is a mixture of falsehood, bias, innuendo, confusion, and tendentious ambiguity. You know it when you hear it. Trump is the master of it, if it’s possible to be a master of garbage. It isn’t trash talk, though it may include trash talk. It’s like shoddy, defective, badly made clothes: it masquerades as quality stuff but will fall apart as soon you put it on. It may be shiny but really it’s shitty. It is irredeemable. Quantifier ambiguity is a sure sign of it: not being clear how many things are said to be thus and so. Do you mean some or do you mean all? As in: “People are saying…” or “They are murderers, rapists, and drug dealers”. Grievance is never far from it. It is always false, but slyly so. It is important that it be complete rubbish—it belongs in a linguistic trash can. It stinks. It isn’t just wrong; it is meant to be wrong. Politicians produce a lot of it, especially on the right; but university administrators (a type of politician) are also prone to it. It is manipulative, dishonest, often rife with buzz words and memes (“diverse”, “safe”, “toxic”, “woke”). The only way to deal with it is to call it what it is, but this violates social norms of politeness and hence is discouraged.

But how is it to be avoided? How does one not talk garbage? Now that is a difficult question, because it isn’t always obvious what is garbage and what isn’t. The essential point is that garbage is generally intended to promote someone’s interests over someone else’s—where the promotion is unjust. It denigrates some and elevates others—unfairly. But this requires us to know what is fair and unfair, just and unjust. We need to know the facts and appreciate the moral situation. This is why linguistic garbage is so hard to root out. It trades on ignorance in the audience, not always culpable ignorance. It is why fact checkers are important. Absent fact checkers, discourse is apt to turn to garbage quickly. Other than that, we have to resort to immediate signs of garbage talk—overconfident tall-tales, unproven theories, omissions, oversimplifications. The garbage-talker is invariably someone who resists cross-examination; he or she won’t answer questions. The thing with garbage is that it is easily exposed as garbage, so it is necessary to keep away from rational scrutiny; it thrives on lack of time to probe and question. The garbage talker tends to run away when the questions start coming. But it isn’t easy to combat it, which is why it is in the ascendant—shamelessly, unstoppably. At least we can name it and recognize its occurrence. The phrase “talking points” performs a useful service in alerting us to a certain sort of verbal activity; likewise, the phrase “garbage speech” can alert us to a type of speech act that is becoming increasingly common and is too much tolerated (“Everyone must have their say”). I recommend using the phrase as often as possible (compare “word salad”). But beware of being guilty of it yourself.[1]

[1] The words “Am I talking garbage?” should always be on your mind.

Book Reviews

I used to write a lot of book reviews—something like 80 of them over a 35-year period. I was known for it. I reviewed in all the best places. You might suppose I must have enjoyed doing it. I did not. It was hard work and not in a particularly good way. You have to come to grips with another author’s work and provide a fair and accurate assessment of it, often suitable for a general audience. Every author you review is a potential enemy, because nobody likes to be criticized, and no book is perfect. I was always relieved when I could write a positive review, even if I had quibbles here and there. But above all it was the time and effort: it distracted me from my own work. It wasn’t what I spontaneously wanted to work on. But it seemed to me like a valuable thing to do—a service to the community, that kind of thing. Many of my reviews had untoward consequences for me (I won’t name names). The reviewee often supposed I must have some sort of personal grievance against him or her, or that I had an ideological axe to grind, or that I was just a mean bastard. None of this was true, but try telling them that. I don’t doubt that I made many enemies, and it was neither fun nor lucrative. Above all, it was counterproductive to my own work; I often wondered if I should simply give it up. But it’s hard to say no to the New York Review of Books.

But during the last 10 years I have done virtually no reviewing. It has changed my life, because in the old days I was always occupied with some review or other. Now I can concentrate on my own work. And what a liberation it is! The luxury of pursuing my own thoughts every day instead of trying figure out someone else’s! I don’t even have to satisfy some editor or other, with their cuts and suggestions (you can’t even imagine). It wasn’t my choice, but it worked to my benefit. It makes me think I should have given up reviewing earlier. Farewell book reviewing, and good riddance!