Are There Psychophysical Correlations?

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Are There Psychophysical Correlations?

The orthodox view is that mental states or attributes are correlated with physical states or attributes. For every mental state M, there is a physical state P such that M is correlated with P (not so in the opposite direction). That is, every mental distinction has a corresponding physical distinction, down to the last detail. By “physical” we are to mean “couched in the vocabulary of brain science”, so neurons, dendrites, action potentials, neurotransmitters—cell anatomy, brain chemistry, electric charge, blood flow, metabolism, connectivity. The classic example is “pain is correlated with C-fiber firing”. This thesis is taken to be both true a priori and also established by empirical investigation—both sound metaphysics and solid science. It is the first dogma of neuroscience. Is it true? What explains it, if true? Two interpretations immediately come to mind, which I will call correlation by identity and correlation by causation. The former models itself on so-called theoretical identifications such as “heat is molecular motion” and “water is H2O” (apologies for the cliched examples). Pain is correlated with C-fiber firing in just the way heat is correlated with molecular motion—by identity. Everything is self-correlated, so we can speak of correlation as identity under different modes of presentation: it is in virtue of identity that water is correlated with H2O. In this sense, Hesperus is correlated with Phosphorous. Such statements are sometimes referred to as bridge laws. This is an awkward way to speak, to be sure, but anyway it isn’t the best way to understand psychophysical correlation, as it is commonly understood. For it is highly doubtful that such identities obtain in the psychophysical case; at any rate, we don’t want correlation to depend on the truth of an identity thesis. Not all correlation is by identity, as a matter of definition or necessity. So, we might move to correlation by causation: brain states cause the mental states with which they are correlated. The correlation is a matter of causal law. There are three possible types of causal relation here: from physical to mental, from mental to physical, and by common cause. We can dismiss the last alternative because there is nothing that could be the common cause—mental and physical exhaust the field. The most favored candidate is physical to mental: brain states cause the corresponding mental state. There are three problems with this idea: the problem of simultaneity, the problem of intelligibility, and the problem of asymmetry. Such causation would make the effect simultaneous with the cause, which is a no-no. Such causation would be unintelligible, which is a disadvantage. Such causation would be asymmetrical, which is arbitrary (why not say the mental state causes its physical correlate?). I won’t labor these points, as the causal model of correlation is not generally accepted, and for good reason (no one wants to say that C-fiber firing is the efficient cause of pain). I mention it to get it out of the way. What people are inclined to believe—and it is a prima facie attractive viewpoint—is that the putative correlation is brute—it is not by anything. It just so happens that pain and C-fiber firing are correlated, but not in virtue of anything. There is no explanation of it, but then again, all explanation comes to an end in primitive facts—basic laws of nature, or brute psychophysical laws in this case. The correlation is projectible in that it extends beyond the observed and even actual cases; it supports counterfactuals, in the lingo. It has the force of necessity, nomological if not metaphysical (that seems a bit strong). Pain is everywhere and always correlated with C-fiber firing, as a matter of natural law. The problem with this is that it is unprecedented: in all other cases of correlation, we have an explanation of the correlation—sometimes by identity, sometimes by causation (over time), sometimes by common cause. Thus, we observe that health is correlated with longevity, height with fertility (Karl Pearson’s example), intelligence with adequate nourishment, strength with size of muscle. In all these cases we can say why the correlation obtains. But not in the psychophysical case—and this is hardly because we are dealing with elementary facts of nature (electrons, protons, etc.). The assertion of bruteness seems ad hoc, arbitrary, and none too credible. Such an association cries out for explanation: there has to be a reason why it is so. It can’t be just a primitive inexplicable fact that pain is correlated with C-fiber firing in all nomologically possible worlds. What is it about C-fiber firing that makes it correlated with pain in particular, and with nothing except pain? Surely, we don’t want to say that it could equally have been the neural correlate of pleasure or deep thoughts of God. We want to avoid such a bizarre conclusion if we can. We might then think to weaken the correlation to avoid problems of explanation: why not say the correlation is completely accidental, utterly contingent, inherently arbitrary? Then there is no nomological regularity to explain, no dangling counterfactual. It’s just like the correlation between coins having the property of being in my pocket and being all dimes—pure chance. Here we might turn to the dictionary (that philosophical treasure house): the OED defines “correlation” as “a mutual relationship of interdependence between two or more things”, or again “mutual close or necessary relation of two or more things”. But mere contingency doesn’t measure up to that kind of definition: where is the dependency, the mutuality, the necessity? C-fiber firing has to be correlated with pain, not just any mental state type. Why, we don’t know, but somehow it has to be. So, the brute contingency position is not recommended: it gives us mere juxtaposition not genuine correlation (interdependence). Our options are rapidly running out. A desperate option would be to go eliminative: there are no mental states to be correlated! The whole thing is a myth, like the correlation between witches and old lady traits—there is no correlation of real things to explain. But let’s not go there yet (or anytime), because there is another possibility: there are no correlations of the kind commonly alleged. The mind exists all right, but it does not stand in correlation relations to states of the brain. Yes, I know that’s a big pill to swallow, but let’s give it a run for its money (we don’t have much else to fall back on). What kind of conception of the mind would lead to such a view? I can think of three possibilities: dualism, behaviorism, and externalism. Dualism locates the mind in a separate realm cut off from the brain; it doesn’t make the brain a necessary foundation for the existence of mental states. Anything could be going on in this immaterial mind quite independently of the brain, so no correlation is to be expected: pain occurring in the mind might be accompanied by X-fibers firing on weekdays and C-fibers firing on weekends, or by no firing at all. Behaviorism locates the mind in overt behavior, so that there is mind if and only if there is suitable behavior, irrespective of what might be going on inside the body (nothing, possibly). Such a position could take in both Skinner and Wittgenstein (see Wittgenstein on the seeds[1]). There need be no correlation between mental states and internal brain states, just identities between mental states and episodes of behavior. Externalism (social or environmental) maintains that the world surrounding the mind (head) fixes what is in the mind, the brain not being in on the act: if thoughts are causally connected to water, they are about water, irrespective of the neural facts. It is the idea that thoughts are purely internal that leads to the brain correlation hypothesis, but once we go external that motivation lapses. So, those are three colorable conceptions of mind that might see fit to abandon the correlation hypothesis, indicating that it may not be compulsory. But we can also step back and notice that there is no real empirical evidence for the metaphysical thesis being advanced: no one has ever observed a precise neural correlate corresponding to a specific thought, for example. How do thoughts about London differ cerebrally from thoughts about Paris? Such empirical evidence as we have concerns gross cerebral localization not precise mapping from mental states to specific brain states. That there is such a granular mapping is a matter of metaphysical faith not established scientific fact. Where is the neural correlate of predication or conjunction or the concept of an even number? What brain properties specifically might stand in such correlation relations—chemical, electrical, anatomical, vascular, metabolic? Is it the shape of a neuron that is correlated with a specific mental attribute? All this is left hazy at best. Granted, the brain plays a vital role in mental functioning, but does it really map so neatly and systematically onto the elements of the mind? Is it true that neural classifications are point-by-point correlated with mental classifications? Why exactly should we believe this? Notice that we can preserve a good deal of materialism by sticking to a token identity theory without presupposing any correlation between mental and physical attributes (our token monism might be completely anomalous).[2] If that were so, there would simply not be the psychophysical correlations that so perplex us—and so nothing that we are failing to explain. There might well be associations, accompaniments, alignments, but not quasi-lawlike projectible generalizations linking mental and physical types. True, this would put us in uncharted territory, sailing towards some sort of dramatic Dualism (that dark and dreamy continent); but we might be willing to explore it given the trouble we are having with the idea of psychophysical correlation. As Kripke once poignantly remarked, the mind-body problem is “wide open and extremely confusing”, so we should be prepared for fundamental upsets in our accustomed ways of thinking. At any rate, the question is worth pondering: can the anti-correlation thesis be defended? Is the brain an adjunct to the mind or a foundation, a partner or a progenitor, servant or master? Are we even thinking about it in the right way?  Is anti-correlational mysterianism the way to go? The mind-body problem is still wide open and extremely confusing, despite valiant efforts.   

[1] Zettel 608. The idea is that two seeds could produce different plants without any internal difference between them. “It is thus perfectly possible that certain psychological phenomena cannot be investigated physiologically, because physiologically nothing corresponds to them” (609).

[2] We could also keep supervenience, since it calls for no correlation between mental and physical attributes, only determination of the mental by the physical, which could be quite holistic. Abandoning psychophysical correlation is not the end of the world for materialism in some form. Then too, there might be higher-order properties of the brain that constitute mental states and hence correlate with them, despite the variations at the basic neural level. The absence of genuine correlations at the level of neurons-as-we-now-conceive-them would explain a lot about our modal intuitions, the possibility of multiple realization, and the force of the knowledge argument. There just isn’t the kind of close bond between mental types and brain types that the usual discussions assume. I wonder when people started to talk this way, and why—was it an offshoot of the development of statistics with its notion of the correlation coefficient? I doubt it originated in direct investigation of the brain. This is a derivative form of description based on unrelated paradigms. We certainly can’t see psychophysical correlations.

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Are There Psychophysical Laws?

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Are There Psychophysical Laws?

This question has been much debated since the publication of Davidson’s 1970 article “Mental Events”.[1]Here I will give my current take on the question. First, we must distinguish strict laws from statements that are lawlike or law-ish, i.e., those that have some nomological force but don’t achieve the status of basic laws of nature. A strict law is fixed, inexorable, universal, and exceptionless; it ensures that “a particular natural or scientific phenomenon always occurs if certain conditions are present” (OED)—with special emphasis on “always”. A non-strict law (better to say “generalization”) is only probabilistic or ceteris paribus—not inexorable and universal. Our question, then, is whether there are any strict psychophysical laws, not generalizations with some degree of nomological force. What would be an example of a strict law? The question might be debated, but prime candidates would be Newton’s law of gravitation, or his three laws of motion, or the laws governing electromagnetism (Lorentz’s force law, Ampere’s law, Faraday’s law of induction, Lenz’s law: you can look them up if you don’t know them by heart). Let’s focus on the gravitational law (it is familiar and intuitive): the mass of the sun (say) acts on the earth over the intervening space and the degree of force it exerts is proportional to that mass and the distance separating the two bodies (the shorter the stronger). What is important is that the law operates continuously, reliably, and without exception—there is no deviation from it. Mass and distance are the only variables involved, and nothing can interfere with the law’s operation—things always work that way. Physical forces are like that: they never let you down, never slacken, never permit exceptions. So, the question is whether psychophysical generalizations are like that—have that kind of regularity, uniformity, simplicity. Consider first belief formation—in science, politics, ethics, aesthetics, etc. Do people believe the same things when confronted by the same evidence? Does the stimulus constituted by the evidence invariably lead to the same belief as response? It does not. No way, no how. The reason is that people form their beliefs based on a variety of factors apart from the objective evidence: their other beliefs, their desires, their personality, what they had for breakfast—and so on. Does everyone arrive at the theory of evolution by natural selection just by looking around at the animals of the world? Of course not; Darwin only arrived at it because he had vastly more evidence than other people, was more intelligent, had greater intellectual integrity, etc. We all live in basically the same world but we form very different beliefs about it. There is no strict law relating sensory input (whatever that is) and beliefs formed; it’s not like the sun’s mass and the earth’s consequent motion. The same physical stimulus does not invariably lead to the same belief formed. The process is more holistic than that, more context-dependent, messier. It is a whole lot more complex. We can’t single out a specific factor and move from that to a prediction about what will happen belief-wise. This is obvious, and it shows that there are no psychophysical laws of that type. Whoever thought there were? But what about perception—are there strict laws governing perception? Here things become less obvious but the consensus is that perception is a lot more like belief formation than has been traditionally supposed: there is no simple automatic transition from physical stimulus, distal or proximal, to eventual conscious percept. I won’t go into the details but we now know that an elaborate quasi-inferential process is at work that supplements and modifies the physical input to the senses. This process is subject to error, breakdown, individual variation, and outright illusion. There is no strict law leading from physical stimulus to veridical perceptual response; there is only the rough generalization “People generally see what’s in front of them”. Even perceptual constancies can be easily disrupted (as psychologists have shown). Not for nothing have perceptual psychologists described perception as a species of hypothesis construction analogous to scientific inference. The perceiver makes an enormous contribution to what is seen; it isn’t a kind of immediate imprinting on the senses—analogous to the influence of the sun’s mass on the earth’s motion (or the effects of magnetism). The earth doesn’t have to interpret the sun’s impact on it in order to know how to move; it’s more like the patellar or blink reflex.[2] Perception is thus like belief formation in respect of its etiology (though not its propositional character) and unlike gravitational influence. Hence there are no strict perceptual psychophysical laws. The causal lines are far more complex and susceptible to subversion; it is not a matter of a single force uniformly doing its thing. The same is true on the output side, and more widely recognized: specific beliefs and desires don’t lead inexorably and universally to a given action; the mind gives rise to behavior in a much more holistic fashion. Again, I won’t labor the point: causal holism is generally accepted where intentional rational action is concerned. But that means that there is no strict law linking specific belief-desire pairs to action types, so there is no strict psychophysical law of this kind either (a fortiori, one might say). The causal sequence is far more circuitous and easily subverted than in cases like gravitation and electromagnetism (we have nothing like “Like poles repel and unlike poles attract”). At best we have probabilities and rules of thumb, not rigid rules and hard determinism. The interface of mind and action is as friable and elastic as the interface between stimulus and percept, more so. Let me sketch an analogy to biology: are there any biophysical laws? Specifically, are there such laws linking survival with physical conditions in the environment, as in the case of shark survival and physical conditions of the ocean? It is well known that temperature and other physical parameters affect plankton proliferation, which affects sardine populations, which affect tuna populations, which affect shark diet (they eat tuna), leading to higher or lower survival rates in sharks. So, we can say that physical conditions in the oceans cause sharks to survive in high numbers or low numbers, as the case may be. But obviously there is no strict law linking these two things, because the intervening variables are so numerous and susceptible to outside influences. We have a huge web of interconnected causal factors at work in producing shark survival or its opposite. Well, the causation of action by the mind is a bit like that: the “stimulus” afforded by a particular belief-desire pair is filtered through a vast network of other mental states that operate in concert to produce a particular behavioral “response”. We don’t have an isolated force capable of producing effects without the cooperation of other variables. In fact, this is the normal state of things: many factors combine to produce particular effects, unlike the pure cases exemplified by gravity and electromagnetism. It would be strange if psychophysical generalizations had the single-minded simplicity of basic physical forces. So, we shouldn’t be surprised if it turns out that strict psychophysical laws are not to be found in nature. Causation is seldom simple and straightforward, and it attains a high degree of complexity in the relations between mind and physical reality. Gravity and electromagnetism are special cases: they obey laws that really are strict and unbending, tunnel-visioned and obsessive-compulsive, uncooperative and go-it-alone. Strict laws have a localized causal structure, but the causal structure of psychophysical generalizations is global and diffused—multi-causal not uni-causal.[3]

[1] I wrote about it in my 1978 paper “Mental States, Natural Kinds, and Psychophysical Laws”.

[2] Notice the law of gravitation doesn’t say that some global state of the sun is the cause of the earth’s motion; it says that mass is, and mass alone. But in the case of the mind many causal factors are at work simultaneously.

[3] This way of looking at things does make the denial of psychophysical laws seem unsurprising and rather banal, not bold and exciting (as it perhaps seemed to Davidson—and to my earlier self). Still, it has the advantage of being demonstrably true (Davidson always admitted that his arguments against psychophysical laws were less than conclusive). Strict covering laws are the exception rather than the rule in the universe as we have it.

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Refuting the Identity Theory

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Refuting the Identity Theory

Suppose someone were to make an outrageous identity claim—say, that Donald Trump is identical to Barack Obama. It would be easy to refute that by pointing out that the two men are to be found in different places, so cannot be the same man—following the principle (beloved of detectives) that one person can’t be in two places at the same time. It is not so easy to refute it by asserting that Obama and Trump look different, sound different, and have a different educational history, because that leaves it open for the identity claimer to say that one person can disguise himself and appear as if two people (Superman and Clark Kent, for example). One person can have two modes of presentation but not two locations. The same point applies to two events: if someone claims that the explosion was the same event as the fireworks display, you can refute this by pointing out that the events occurred two miles apart—though it isn’t so easy to argue that the appearances were of different events. Such identity claims are vulnerable to what we might call the “location argument” (as opposed to the “appearance argument”). They are thus falsifiable by recourse to location. However, in the case of the mind-brain identity theory this recourse is not available, because the mental event has no identifiable location: you can’t point to it in space and observe that its location differs from that of its correlate in the brain. If someone says C-fibers are identical to D-fibers, you can point to the D-fibers and observe that they are not where the C-fibers are, thus refuting the identity claim. But you can’t do that with pain: it has no identifiable location. So, the primary method for falsifying identity claims about empirical particulars is not available. You are left weakly protesting that pains don’t appear like states of the brain—to which the identity theorist will retort that one thing can have two appearances (though not two locations). This gives the identity theorist an unfair dialectical advantage: no matter how preposterous his claim is he cannot be refuted in the standard fashion. Even if the pain exists in a separate immaterial substance, you cannot demonstrate this by pointing to its different location. Not because it has the same location as the brain state but because it has no location, or none that can be pointed out. It is simply in the nature of the case that it lacks a distinct observable location, not because the identity theory is true. One suspects that identity theorists have got a good deal of mileage from that fact: they can complacently point out that no one has ever refuted their claim in the only way it can be, conclusively anyway. But this is nothing to their credit, since it follows equally from the dualist perspective: the pain could be as ontologically distinct from its neural correlate as you could wish and still not be capable of being located elsewhere. The location argument thus can’t be used against the identity theorist, but not because there is any truth in his position. Once this is recognized we can lean more heavily on such arguments as that pains and brain states seem very different, or that you can know all about the latter and not know about the former, or that in some possible worlds there are pains and no C-fibers. It shouldn’t worry you that you can’t falsify the identity claim in the canonical way.[1] It should worry the identity theorist that he can’t locate pains in space at all, independently of the truth of his identity claim. The case is not like a single mountain seen from different perspectives.

[1] If it turned out (per impossibile) that your pains exist in the back of your closet, you would have a cast-iron proof that they cannot be brain states (no sign of your brain in there); and then it would be perfectly clear why pains and brain states should have such different appearances—they are totally distinct entities. You might then wonder about the properties of your closet—does it have a peculiar aura of subjectivity about it?

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On Drumming

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On Drumming

My thesis is that all playing of musical instruments is drumming. Drumming is what they all have in common, what constitutes their underlying real essence. It might be thought that this cannot be right, because drums are a rhythm instrument and other instruments are used to produce melody. But actually, drums also produce melody in that they have different tones or pitches (drums proper as well as cymbals). Without these tonal differences a drum set would be a poor musical instrument (monotonous, boring). The pitches succeed each other musically and can be superimposed to produce chords. And clearly, we can envisage drum sets that are more tonally designed, with each drum tuned to a specific note and melodies played by striking these drums. There is nothing atonal about drums and drumming. A good drummer (especially a jazz drummer) will use pitch and timbre differences to accentuate and enliven his or her playing. But how can other instruments be forms of drumming? Consider first the xylophone: it is very similar to a set of drums and clearly the act of striking the plates is a type of drumming. The OED gives us the following for “drum” (verb): “beat or play (as) on a drum; make a continuous noise by rapidly repeated blows”. For “drum” (noun) we get: “a percussion instrument sounded by being struck with sticks or the hands”. These definitions fit the xylophone perfectly—and you just have to look at a xylophone player to see the similarity to paradigm drummers. A device (“stick”) is used to strike or tap or otherwise impact a surface that responds by making a particular sound the purpose of which is to produce music. There would be no essential difference if the plates were replaced by drums. True, we don’t call xylophone players drummers, but that is because such a description would be misleading for conversational implicature reasons; however, it is literally true that they employ drumming motions in playing their instrument. Now the piano: the hands are brought down on the keys which then produce notes by way of the instrument’s mechanism. The fingers work percussively (OED: “the action of playing a musical instrument by striking or shaking it”). The pianist is a species of drummer: he hits keys that produce sounds in response. You might say that he also touches or depresses keys, but remember that drummers sometimes use brushes not sticks—it’s not all vigorous banging. And some pianists are highly percussive (e.g., Jerry Lee Lewis, Little Richard). What about stringed instruments, which may be picked, plucked or bowed? Well, they too are operated by means of percussive actions, more or less vigorous (think of Pete Townsend’s slamming chords). Again, we have a striking action performed on a responsive medium—but a string not a membrane (the drum head or skin). It would be possible to stretch a string over a drum head and pluck it so as to make it strike the drum; that would still be a type of drumming.[1] So, playing guitar, say, qualifies as a form of drumming, as does violin playing. The interior of the instrument (resonance chamber) resembles the interior of a drum, and the action of playing it is like striking (or brushing) the skin of the drum (you can drum your fingers on a table, remember). There is no reason of principle why you couldn’t bow the head of a drum; to be a drummer it is not necessary to drum—you can also scrape, stroke, and palpate. You could be a drummer and never actually drum, or use a drum for that matter. So, logically, pianists and guitarists could be drummers without using drums or even drumming. Still, I prefer the strong and simple thesis that all instrumentalists are drummers, all instruments are drums, and all playing on instruments is drumming. Any oddity in these propositions arises from conversational implicature; logically, drumming is the rule, the universal. Drumming is the underlying essence of all these activities; it is the natural kind that subsumes them. But surely (you protest) wind instruments are not drums and playing them is not drumming—there is no use of hands or feet! By now my response to this will be predictable: first, the hands and fingers are used in depressing the pistons or blocking the holes; but second, air is forcibly expelled into the instrument causing it to vibrate and respond with a particular sound. Drums could be played this way too: a burst of air could be directed at the drum head and a sound elicited. We have a physical (mechanical) stimulus and a musical response—an impact producing a sound in the course of making music. What if the trumpet player were to produce a series of sharp bursts of air that impact the reed and produce rhythmic sounds—wouldn’t that be very like playing the drums? It might even be synchronized with the drummer; the trumpeter has joined the rhythm section. Bass players and rhythm guitarists are already there, striking strings. Finally, the voice: again, this is not difficult to slot into place—the singer drums (percusses) by propelling air into the vocal cords (really vocal membrane) and producing musical sounds. We are familiar with beat-box voicing—imitating the sound of drums with the mouth—so it is not much of a stretch to include ordinary singing in our natural kind. Singing is a variety of percussion—one thing hitting another to produce musical sounds. Tap dancing is also a type of drumming and may be used musically; singing is really not all that different—vocal tapping (using the larynx to produce music by physical impacts). So, all music-making is really drumming: this is its hidden architecture, its compositional make-up, its basic anatomy. There is a continuum from regular drums through xylophone, piano, violin and guitar, wind instruments, and voice—with no natural break or division. Probably drums are the oldest of these instruments, and most primordial, but other instruments build on the same basic idea.[2] That is why it is natural to pick drums out as paradigmatic, but really, we have a family of instruments all united by a common principle—by the mechanism of percussion. We hit things to make sounds and then we string these sounds together to create rhythm and melody. All music is drumming refined and extended. The drummer is the progenitor of all music. Ringo Starr was well-named: he made the Beatles possible.[3]

[1] The snare drum consists of a bunch of wires stretched tight over the reverse side of the drum, so the snare is stringed in much the same way a guitar is.

[2] I suspect that football (soccer) plays a similar role in the genesis of other sports: all other sports are variations on it or developments of it. Don’t say that football isn’t played with the hands, as many other sports are. First, football is partly played with the hands (throw-ins, goalkeeper); and second, the feet are always involved in hand-centered sports, because players have to run around. The basic form of sports consists of an object (often a ball) that is moved around in a competitive activity. Kicking a ball is one of the first sporting activities kids learn. But I won’t go into this further.

[3] Does it surprise you to learn that I was originally a drummer who moved onto guitar, harmonica, and voice? I always kept my love of drums, however. I believe that drumming is a basic human need. Drummers don’t get the respect they deserve. Drummers are close to the World Spirit (as I’m sure Charlie, Keith, and Ringo would agree, all singular figures). Drummers are cool.

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Identity and Synonymy

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Identity and Synonymy

It is commonly supposed that “water is H2O” is both known to be true and synthetic (hence a posteriori). I think this is not so. The reason is not difficult to see: if the sentence is known to be true, then speakers will associate the same descriptions with each term (following Leibniz’s law), so the sentence will be analytic for them.  Consider a group of scientists working in the same lab and knowing the identity of water and H2O: when they speak to each other they use the two terms interchangeably, knowing that the denoted things are identical. For them, the terms are synonymous and the sentence “water is H2O” is analytic. It is always possible to substitute these terms in belief contexts, given that everyone knows the truth of the identity statement (and knows that others also know it). Nobody thinks there is any more to one of the denoted things than the other: there is complete ontological parity, utter indiscernibility. They might even use “hydrox” as a more vernacular term than “H2O”, so producing the identity statement “water is hydrox”, which is also analytic (everyone assents to this sentence). Before the discovery of the identity people would suppose the two terms had distinct references, but afterwards the difference of meaning disappears. It is the same with Hesperus and Phosphorous: once the identity is discovered and generally accepted “Hesperus is Phosphorous” is analytic, since whatever is believed true of one is believed true of the other. This means that being synthetic is not compatible with being known to be true: no identity statement can be both. Of course, a false identity statement can be synthetic, given that the two terms have distinct references. All this seems clear enough, but matters turn murkier when we come to statements like “pain is C-fiber firing”. Here we are encouraged to believe that the statement is both true and synthetic—informative, a posteriori. It could have those attributes and be false, but it is said to be both true and synthetic; it is “empirically true”. This combination is supposed to be exemplified in such statements as “water is H2O”, thus providing a precedent for the claim of identity between pain and C-fiber firing. But I just argued that the former case is not an example of a synthetic identity statement. So, if the latter case is synthetic, as it seems to be, then this can be so only because it is not true (and known to be true). The explanation of its appearing not to be analytic is simply that it is not true—the two terms refer to distinct properties. If it were known to be true, then speakers would associate the same descriptions with each term, thus rendering the statement analytic. This doesn’t happen because speakers can see that the two terms have different denotations, so the statement can’t be analytic. The case is essentially like “creature with a heart” and “creature with a kidney”: the two predicates are coextensive (the properties denoted are correlated), but the properties are numerically distinct. Similarly, “pain” and “C-fiber firing” are coextensive (the properties are correlated), but the properties themselves are numerically distinct. This is the reason the statement is not analytic: there is more to pain than C-fiber firing, as any competent person can see. That is, the identity theory is false. And its characteristic formulation has no precedent in the sciences—no identity statement can be both known to be true and synthetic. Therefore, we cannot be lulled into accepting the truth of “pain is C-fiber firing” by alleged cases of known synthetic identity in the (respectable) sciences. If that sentence were an accepted identity sentence, then it would have to be analytic; but it isn’t, so it must be false. The explanation of its apparent non-analytic status must be that the properties are distinct, recognizably so. In other words, the identity could only be known to be true by being a priori—as in the case of “water is H2O”. Once that statement is known (or believed) to be true it becomes analytic, as it is for my group of savvy scientists; but this can’t happen with “pain is C-fiber firing” for the simple reason that the alleged identity claim is patently untrue. Ifpeople came to accept it as true, then it would be analytic for them; but it clearly isn’t analytic for anybody, so it cannot be true. There is no obstacle to water being recognized as identical to H2O, since there is demonstrably nothing more to water than H2O; but there is an obstacle to recognizing that pain is identical to C-fiber firing, namely that there clearly is more to pain than C-fiber firing. If that were not so, then the identity statement could be happily analytic—but that it can never be. The sentence is robustly synthetic, permanently informative, indelibly a posteriori: but this is incompatible with the truth of the identity statement. For, if the statement were true, it would have the status I attributed to “water is H2O”—an analytic truth. The fact is that there is no meaningful analogy between “water is H2O” and “pain is C-fiber firing”. Accordingly, the only way to make good on materialism is to provide an a priori analysis of the concept of pain—just the kind of thing attempted by the analytical behaviorists and functionalists. The idea of an empirically true central state materialism is a chimera born of a faulty analysis of so-called theoretical identifications in science. The mind-body problem requires an a priori analysis of the mental. No adequate solution can take the form of an a posteriori synthetic reduction of the mental to the physical. None of the standard alleged analogues have the properties required: “heat is molecular motion”, “light is a stream of photons”, “genes are strands of DNA”, etc. These all involve post-discovery synonymy, produced by the operation of Leibniz’s law. Once you discover that Hesperus is Phosphorous the names “Hesperus” and “Phosphorous” become synonyms for you, intersubstitutable everywhere salva veritate. There is no such thing as a known synthetic identity.[1]

[1] It might be said that this is too strong, because some identity statements contain definite descriptions that enable them to be both known and synthetic (“Benjamin Franklin was the inventor of bifocals”). But this is to overlook the point that such descriptions will typically contain terms that refer to distinct properties or objects. In cases in which this isn’t so we get full synonymy, as in “the bachelor at the back is identical to the unmarried man at the back”. It is really always reference that ultimately determines whether words are synonymous or not.

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Shark Attacks

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Shark Attacks

I recently read Francois Sarano’s excellent forthcoming book In the Name of Sharks (sent to me by the publishers because I wrote a review of a book about the octopus in the Wall Street Journal). It puts up a strong case for the preservation of shark populations in the face of dwindling numbers and impending extinction. The shark has a bad reputation in the human population, fed by prejudice and irrational fear (Steven Spielberg has a lot to answer for in spearheading the human desire to eliminate sharks from the face of the planet). It turns out that shark attacks (Sarano calls them “accidents”) are almost invariably caused by fear (on the part of the shark), territoriality, self-defense, and misunderstanding—not by wanton aggression or predatory behavior. Sharks are not innately violent or perpetually angry. They don’t attack for no reason. They are actually pretty nice, even lovable. This set me wondering about other vices in human and animal populations: do we find counterparts of human vices in other species? Is there wanton aggression, cruelty, torture, bullying, murder, hate crimes, sadism, emotional abuse, malicious gossip, defamation, nasty comments? Apparently not: such evils exist only in human populations. Animals can certainly be violent, but there is a point to it; it isn’t motivated by sheer malice. There are no Iago’s of the animal world. If we want a trait that sets us apart from animals, sheer nastiness would be a good candidate. Even sharks look upon us with disgust and horror.

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Am I Certain That I Exist?

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Am I Certain That I Think?

Descartes wanted to build human knowledge on a foundation of certainty. He thought the Cogito provided an instance of certainty, and many have agreed (Montaigne was there before him). Critics have argued that the conclusion of the Cogito doesn’t follow from the premise (the Lichtenberg objection). However, the premise itself is seldom questioned; it at least is certain, whether or not it entails the existence of a thinker. But is it certain? First, we need to ask what it means: when I say “I think” what proposition am I asserting? Does it mean the same as “I am a thinker”? And does that imply “I am a rational thinker”? Am I asserting that I think rational thoughts?  But there are two problems with this interpretation: (a) how can I be certain that my thoughts are rational and (b) how can I be certain that I have thoughts plural? What if there is a brain disease that renders my thought processes irrational while giving me the illusion that they are rational? I can’t rule this out with certainty. And how can I be certain that I have thoughts in the plural given that this will require a series of thoughts over time? I can’t be certain I have had thoughts in the past since memory is fallible, and the existence of future thoughts is even less certain. So, should “I think” be read as “I have a thought now, which may or may not be rational?” But is it possible to have only one thought and it be completely irrational? Would that even be a thought? Thoughts occur in series of linked thoughts (“temporal holism”), and their title to being thoughts surely depends on some degree of conformity to rationality, however minimal. But these requirements are not open to certainty. In addition, thoughts in the ordinary sense have intentionality, but is that open to certainty? Couldn’t I be having thoughts about nothing—how can I be certain that my thoughts are aboutthings? What thought is it that I am supposed to be certain I am having? Is it the thought that it is (say) raining in Miami now? But how can I be certain my thought is about Miami and rain—what if I am a brain in a vat and content externalism is true? Is it the thought that I think (“I think that I think, therefore I am”)? But then we are back with the problem about rationality and thought plurality. It looks as if we need to retreat inwards a step: “I seem to think, therefore I am”. We thus cancel the proposition that I really think and maintain more modestly that I appear to myself to think. This falls far short of the original Cogito in that it concedes that I cannot be certain that I think: that proposition cannot be the premise the Cogito works with. We can gloss “I seem to think” as “I may be thinking now but maybe I am not—it only seems to me that I am”. Is this strong enough to get the conclusion we want? It seems like a very flimsy foundation for erecting a tower of certain knowledge. And if we are to retreat to a “seems” version of the premise, why not say simply “I seem to exist, therefore I exist”? For, if we can’t appeal to an unqualified “I think” but must restrict ourselves to “it seems”, then we may as well do it straightforwardly and honestly—”I seem to myself to exist, therefore I must exist”. But that looks like a straight non-sequitur: how can my existence follow from the mere appearance that I exist? Don’t we need the existence of something real to get anywhere—as in the existence of real thoughts? How can seemingentail being? Certainly, this revised Cogito looks weird and fishy compared to the classic version—hardly self-evidently true. This impression is confirmed by raising another skeptical possibility, namely that we can’t get existence out of seeming existence—out of the mere impression of existence. Nor can we get it out of the mere impression of thoughts as opposed to real thoughts. Suppose you are Meinong and believe in different kinds of being, subsistence and existence: maybe you can derive self-existence from genuine thought-existence, but how can you derive it from mere appearances of existence? Surely subsistence could seem like existence, so it may be that the self you derive from “I seem to exist/think” is just a subsistent entity not an existing one (like a hallucinatory golden mountain that looks real). In order to rule this out you would need to refute Meinong by claiming that all subsisting objects are existing objects—or else the Meinongian will insist that the conclusion could only be that I have some sort of being. In other words, the seeming premise only licenses an inference to “The subject of this seeming has being of some sort”. To be more specific, how can I be certain I am not a fictional character? It can seem to a fictional character that he thinks and exists, but he is not thereby a thinking existing being like you and me (as we believe, at any rate).[1] Or if you hold that fictional characters really have existence, then the new Cogito has to conclude “Either I exist in the real world or I am a character in fiction”—not quite what Descartes was hoping for. The problem is that seeming is too weak to give (real) being, but we can’t justify the original premise that asserts certainty about the existence of thoughts (thinking). Can we assert the existence of real seemings? If so, we might be able to move to real subjects of seemings. But of course, there can be fictional seemings: it can seem to a fictional character that things are thus-and-so. I therefore need a way of showing that my seemings are real, but all I am entitled to is that they seem real. We are now at an argumentative stalemate, whereas the original Cogito at least purports to start from a premise about incontestable reality, viz. the known reality of thoughts and thinking. The idea was that we can know with certainty that thinking really exists and then move from this to the existence of the self. But it now turns out that only a “seems” premise is acceptable, which undercuts the move to an “is” conclusion (“I exist”). So, Descartes needs his version of the Cogito and not the weakened “seems” version: if the argument were equally good under the “seems” interpretation, he could have simply said “I seem to exist, therefore I exist”—which looks like a blatant non-sequitur.[2] But the original version is open to skeptical doubt about the premise itself, not merely about the validity of the inference. The lesson is that trying to base human knowledge on certainty is hopelessly quixotic and should not be attempted (unless we stick with the ordinary man’s use of “certain” and forget about philosophical skepticism). Or to put it differently, an epistemology of science should not be in the business of refuting skepticism. It will only take a sound beating if it chooses to take on the skeptic (like Don Quixote himself fighting foes far more powerful than him[3]). Descartes clearly had problems with his attempt to prove the external world (what with the ontological argument and God’s supposed non-deceptive nature), but in fact the problems begin much further back with his attempt to find at least one indubitable proposition. It is the whole Cartesian project that is at fault. Certainty is a false god.

[1] This is exactly the situation of two characters in Sophie’s World by Jostein Gaarder (1994): they think they are real but discover that they are characters in someone else’s work of fiction. Fictional characters cannot use the Cogito to prove they are real.

[2] There is also the problem that in order to know that it seems to me that I exist, or that I seem to have thoughts, my seeming must have intentional content; but how can I be certain that it does, given that this doesn’t depend solely on my inner state? The skeptic will argue that my seeming might not have the content I take it to have, if I am a brain in a vat or sufficiently mentally deranged or confused. Episodes of seeming can be as subject to skepticism as thoughts are with respect to their content. Things are not as simple as Descartes supposed.

[3] Don Quixote de la Mancha cuts quite a philosophical figure: even after a series of terrible drubbings he refuses to abandon his absurd delusions, despite the entreaties of Sancho Panza (the voice of common sense). He is the living embodiment of human error—of life inside Plato’s cave. Descartes is quixotic in the precise sense that he keeps fighting for his misguided ideals even when he is clearly outgunned by the evil demon; he is too entranced by the romance of complete certainty. There is a nobility to this, but it’s none too realistic.

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Seeming

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Seeming

Seeming is a pervasive feature of conscious life. We (and other animals) are constant subjects of seeming: things are forever seeming this way or that to us. It now seems to me that there is a red cup in front of me, that Sebastian is in a good mood today, and that seeming is a worthwhile topic for philosophical investigation. Consciousness could almost be defined by way of seeming: it is a center, a hub, of seeming. What it is like to be x is how things seem to x, and where there is seeming there must be consciousness. Sentience is seeming. Oddly, our vocabulary for it is quite limited: in addition to “seems” we have “appear” and how things “strike” us, but not much else. Synonyms are thin on the ground, despite the ubiquity of the phenomenon (is this a sign of poor comprehension?). What exactly is seeming? It might be thought to be a species of belief, perhaps the tentative kind: if it seems to you that p, then you (tentatively) believe that p. While there is certainly a correlation between seeming and believing, it would be wrong to define the former by the latter, since it is possible to disbelieve what seems to you to be the case (or to be neutral about it). If you have reason to believe you have been hallucinating recently, you may distrust your senses and reject the appearances they offer to your faculty of judgment. Seeming may be something like an invitation to belief, but you can decline the invitation. Nor is belief sufficient for seeming: I believe the Sun is 93 million miles away, but it doesn’t seem to me that way. Seeming looks like a sui generis state of mind, not to be assimilated to belief. It is also shared by different sense modalities and indeed by other modes of knowing: both sight and hearing (etc.) provide us with occasions of seeming, so the nature of seeming cannot be defined in terms of specific types of experience. What we can say is that all knowledge depends on episodes of seeming: we can’t know things without things seeming a certain way to us. Seeming plays a vital epistemological role. What we believe depends ultimately (sometimes directly) on how things seem to us. So it would be good to know what seeming is, how it is to be analyzed. When it seems to me that p what kind of mental state am I in?

            The answer might seem straightforward (note how frequently we use the word): I am in a subjective state that has representational content (intentionality, reference). In short, seeming is experience. But that can’t be right as stated, because mental images fit that specification: they are subjective states with representational content, but they are not states in which the world seems to be a certain way. Mental images are not hallucinations and do not present themselves as such. I am not tempted to believe what they represent; they don’t function as evidence for me. Here we might reach for the concept of the sense datum: a seeming is a sense datum, a constituent of perceptual consciousness. This suggestion encounters a problem with non-sensory seeming, unless we enlarge the concept of a sense; but there is a subtler problem, namely that the sense datum, as traditionally conceived, is too weak to add up to real seeming. The intuitive idea is that a sense datum is an intrinsic state of consciousness that transparently presents itself to the knowing subject—not very different from a pain or tickle (“My visual field is yellowish”). But why should that add up to a way the world seems? The sense datum is conceived as a floating element of consciousness—a quale in modern terminology—but where is the idea of how things seem in that conception?  Couldn’t such an entity be present in consciousness and not strike the subject as pointing to how things external to him actually are? The sense datum is too neutral, too isolated within itself, too uncommitted. It is too much like an image or idea or concept: it doesn’t carry within it the element of world-directed commitment. It just hangs there. You can see what I am driving at by consulting the dictionary: the OED gives an admirably concise and abstract definition of “seem”—“give the impression of being”. We could choose to build this into the notion of a sense datum, but the traditional notion is not so understood. There are two aspects to the definition: beingand impression. Seeming is the appearance of being—existence, reality, externality. It isn’t a neutral quality of consciousness: it points outwards; it has (purported) objectivity. This is more than mere intentionality, since that is compatible with the fictional or subjective status of the intentional object. But in the case of seeming we have apparent reality. When visual experience makes it seem to you that there is red cup in front of you it makes that state of affairs seem real—objectively real, really there. The concept of seeming is connected to the concepts of fact and truth; indeed, it is up to its neck in the idea of an objective, shared, external reality. All seeming is existential seeming (unless explicitly about fictional entities). The senses make the external world real to consciousness (whether or not it really is). If it seems to you that p, then it seems to you that it is true that p (factual, part of being). Seeming is ontologically committed. It isn’t ontologically neutral like traditional sense data or physical stimuli impinging on the sense organs. You need not believe what it purports to reveal, but it certainly has strong opinions (as it were). Seeming is a realist: it affirms the transcendent. The second element is the concept of impression: in seeming you have the impression of reality; you are affected that way. The seeming makes a certain impact on you. Not necessarily a belief, but some sort of mental effect (the word “impress” can mean “make a mark or design on (an object) using a stamp or seal”: OED). You have, as we say, the distinct impression that things out there are thus and so—really thus and so. You may be cut to the quick by this impression, or elated by it, or sublimely indifferent to it. How things seem concerns the self: it is the self that is impressed by the (apparent) encounter with being. But this fact—the fact of having the impression that p—fits none of the standard mental categories, being neither belief nor sensation. It is sui generis and rather puzzling, despite its familiarity. Seeming is neither assent nor feeling, but somehow something in between. It concerns reality and is clear in its commitments, but it isn’t a type of belief—though it functions as an invitation to belief. We might say it belongs to its own mental faculty, alongside the faculties of belief formation, imagination, emotion, etc. It provides input to other faculties but isn’t a special case of them.[1] It demonstrates the variety of the mental (and the dangers of that overarching concept). The seeming faculty is in the business of providing impressions of being (though it can fail in its mission), which we must evaluate in order to arrive at beliefs. These impressions are useful and sometimes impressive (waterfalls, mountains, whales) and no doubt serve a biological purpose. But they are rather mysterious, being neither fish nor fowl. It is hard even to talk about them: we are left with the bare claim that the mind is capable of entertaining impressions of reality that don’t ascend to the level of belief (but do go beyond mere subjective items).

            We can now define “seems”, notwithstanding its puzzling status. It seems to an organism that p if and only if the organism has an experience in which it has the impression that p. More briefly, seeming is having an experience-based impression of being. Here we leave “impression” as undefined (the dictionary is no help); it must be taken as primitive. All we can say is that it is not a case of belief (or disposition to belief). Such states, however, are the basis of all knowledge. Hamlet’s famous line “Seems, madam! nay it is; I know not ‘seems’” encapsulates a good deal about seeming: its relation to being and its puzzling status. The traditional philosopher would put “is” after “I know not” (skepticism etc.), assuming that how things seem can be known; but Hamlet seems (!) to be saying that he doesn’t know anything about seeming. What is this strange seeming, this curious hybrid, this committed agnostic? I understand “To be or not to be”, but what are we to make of “To seem or not to seem”? I know not that, Horatio. Poor Hamlet, he doesn’t even know how things seem, let alone what really happened to his father or the nature of the afterlife! Our ordinary language also seems to be in some doubt on the matter: there are verb and adjective forms of “seem” (“seems” and “seeming”), but there is no noun form, as if English is reluctant to engage in the ontology of seeming. I have spoken in noun form of “a seeming” and “seemings”, as if there are such things, but that is not regular English. English, like Hamlet, knows not “seemings” or “a seeming”. Yet seeming seems real (I have the strong impression that seeming has being)—there are seemings of seemings. But they are puzzling conceptually; perhaps this is why they are seldom discussed, or assimilated to something else. We need a philosophy of seeming (not of physical sensory inputs or amorphous “sense data”); in particular, we need a better understanding of the notion of “impression”. Perhaps seemings are supervenient on other mental phenomena such as experiences of one kind or another, but we should be wary of any attempt to reduce them to such a basis. Do experiences cause seemings? Is it because of experiences that things seem a certain way, even though seemings strictly transcend experiences as such? Or are the things we call “experiences” really compounds of seeming and some more primitive sensory material? And how do experiences make an impression on the subject, whatever that effect is exactly? Hume spoke of impressions and ideas, recognizing that the senses do more than just parade ideas before our minds, but he said nothing to explain what an impression is, i.e. what it is an impression ofand what it is an impression to. We are constantly having impressions of this or that, but what this operation amounts to remains obscure. Metaphorically, it is something like an imprinting (a type of denting), but that tells us little of any theoretical use. All knowledge therefore rests on something we don’t understand.[2]

Colin McGinn

[1] Someone might try saying that seemings are the beliefs of the perceptual modules, potentially in competition with the beliefs of the central system, as in cases of visual illusion (see Jerry Fodor’s The Modularity of Mind). But that is an anthropomorphic picture of the perceptual systems: nothing in you believes that the lines of the Muller-Lyer illusion are unequal (assuming you know the illusion). The seemings of the senses are completely non-doxastic. It is merely as if your visual system believes what it delivers. Belief is really the icing on the cake not fundamental epistemological reality.

[2] If we say all knowledge rests on observation, we tacitly bring in the idea of seeming: an observation is a mental act in which something seems to be the case. That is, observations are precisely conscious states that embed an impression of being: the observer is affected by reality in a certain way and he seems to himself to be so affected. We can’t avoid admitting seeming into the epistemological picture in favor of something (seemingly) less obscure. Seeming is inescapable.

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