Modularity and the Self



Modularity and the Self



We don’t always speak with one voice. We disagree with ourselves. The senses may say one thing while we say another. The classic case is visual illusion: the visual system may represent the world in a certain way, but reason says otherwise. The encapsulated visual module delivers an output that the central cognitive system contradicts.[1]There is internal dissent, discord in the ranks. One part of us says one thing while another part denies it. This can be global as well as local. Suppose someone arrives at the conclusion, on philosophical and scientific grounds, that ordinary material objects are neither solid nor colored: no matter how strongly held, this conviction will not alter how things visually seem. So the disagreement will persist indefinitely: the subject will disagree with his own senses. The same is true even for the belief that one is a brain in a vat seeing nothing: perception will keep on representing the world as if the subject were surrounded by objects of a familiar type. Perception is oblivious and impervious. If we think of perceptual outputs as assertive acts, then the visual system is saying “objects are solid and colored” or “I am really seeing external objects”, while the forces of reason are asserting the contrary. It is not common usage to report the senses as believing what they represent, but there is certainly something belief-likeabout what they do—they are committedto a certain view of things. They are not merely suppositional, as the imagination is; they make definite claims—as that objects are solid and colored and are really there. To say, “My visual sense believes that the two lines are unequal” while in the grip of the Muller-Lyer illusion is not wide of the mark—maybe it is even true unconsciously. Imay not be conscious of this belief, but my visual system might hold to it; in any case, it doesn’t seriously misrepresent the facts to say so. We might then describe the situation as follows: the senses believe that pbut reason (the central system) believes that not-p. Intrapersonal disagreement mirrors interpersonal disagreement. Cognitively speaking, we are at war with ourselves. The senses can’t bring us round to their point of view, but neither can we get them to accept ours. There is a split in our world-view: that is, our cognitive modules are not aligned.[2]

I put the point this way in order to accentuate a question, namely: Where is the self in all this? So far I have spoken of one module thinking one thing and another module thinking another, but this is not how we speak. I say, “My senses think (assert, believe, represent) that the lines are unequal, but Ithink they are equal”. So I seem to be supposing that one of my modules is more closely aligned with my self than the other: I merely havesenses, but I amwhatever it is that issues considered judgments. So my senses think one thing while I (my self) think another. The picture is that there is a supervisory self that evaluates what its several modules assert. And Ican reject what theyassert. They are something other than me, but I am not. Given that reason is what makes such judgments possible, it looks as if I am identical to reason: reason is what I refer to when I say “I”—not the senses. I might say, “My senses are misleading me badly” but not, “My reason is misleading me badly”—for that would be equivalent to saying that Iam misleading me badly. The senses are behaving like other people in relation to me, but I could not behave like another person in relation to me. At any rate, that is how we appear to conceive of ourselves: we privilege one module (faculty, capacity) over another in these internal disagreements, aligning it more closely with the self (maybe even identifying the two).

But what is the rationale for this? Why this aristocracy of reason? What if we inverted the privilege, asserting that I think the lines are unequal while my reason thinks they are equal? What if I preferred to link “I” to the senses not the intellect? What if I thought the soul resides in the senses not in the rational faculties?  We do have the locution, “I see the lines as unequal” as well as, “My visual sense tells me the lines are unequal”; so it might seem arbitrary to assign seeing to sense organs and thinking to the self, instead of assigning thinking to the rational faculty and seeing to the self. What if we simply adopted an organ theory of psychological ontology in which the self is no sort of additional entity? The sense organs give one sort of informational output while the central system gives another sort, with neither assigned preferentially to the self? The two organs disagree, but there is no selfthat takes sides in the disagreement: it is just reason versus sense, with no self in view. If we keep the word “I” in the picture, it seems that it can apply both to the senses and to reason—as in, “My reason tells me that not-pbut I see that p”. Why exactly do we talk as if I think but my eyes see? Descartes doesn’t say, “My reason thinks, therefore it exists”; and there is a long tradition of regarding reason as constitutive of the self. But it seems okay to say that my eyes (and brain) do the seeing—Isee only derivatively. This is why we so readily say that our eyes are deceiving us, but not that our reason is. The organ of sense is intuitively not a candidate for identity with oneself, while the organ of thought is. The central system is closer to methan the peripheral systems. Or so we tend to suppose. But why is this?

I raise this question in a spirit of puzzlement. A no-self theory removes the puzzle because there isno self to attach to a given mental organ—there are just ways of talking using “I”. It is not that reason is identical to the self and the other organs of mind lie outside the boundaries of the self (its little helpers, as it were); there is just the faculty of reason coexisting with the other faculties of the mind. The mind is a federation not a monarchy. But that is a drastic position, and one that flies in the face of common sense (but not to be dogmatically dismissed). The weaker position is that there is no difference between sense and reason in respect of the self—the self belongs to each equally. This too is a bit of a strain: we really do think that our senses tell us things and that we may or may not heed them. We listen to our senses, but we don’t regard them asus. The central system of belief formation is what does the listening; it is where Iam. If there were no such system, there would be no I: but you can lose your senses and still exist. The problem is that internal disagreement puts a wedge between one part of the mind and another part, and the self has to fall on one or the other side of this divide; but why it falls as it intuitively does remains obscure (hence the appeal of the no-self position). My senses relate to me as other people relate to me—as sources of information with which I may disagree—so they are regarded as distinct from me. But it is harder to think of reason that way: it is not like an external informant with whom I can sensibly dispute. For what could that be if not my faculty of reason itself? And a bare transcendent self has no opinions with which to contradict other opinions. So the self aligns itself with reason as against sense—a very Cartesian position.[3]Yet the matter remains obscure.


[1]I am assuming Fodor’s position in Modularity of Mind(1983).

[2]The case of dreams is peculiar: dream content can certainly contradict what we believe when not dreaming, but it isn’t like perceptual illusion. It isn’t cut off from what we think in the way the senses are. It lies midway between sense and reason (rational thought). We might describe it as “semi-encapsulated”. Memory and the unconscious raise similar issues.

[3]The Cartesian might claim that thought essentially links to the immaterial ego while perception links to material sense organs; thisis why we talk as we do. That would be a kind of metaphysical reification of what must have a less startling explanation. And we know that “I” is a very funny word.


The Inefficacy of Skepticism




The Inefficacy of Skepticism



There is something peculiar about skepticism, psychologically speaking. It seems both cogent and ineffectual. Our epistemic practices are roundly criticized, convincingly so, and yet we decline to modify them; we soldier on regardless. We don’t refute the skeptic, but we don’t heed him either. Why are we so complacent, stubborn, and irrational? We are like flat-earth true believers who know all the refutations of their position but cling to it anyway. Of course, there are those who seek, by a variety of stratagems, to blunt the force of skepticism, thus bolstering their initial naïve epistemology; but this always reeks of cognitive dissonance, and is generally unpersuasive. And there are many others who reject such soothing stances and yet still decline to alter their epistemological assumptions—what is it with them? Skepticism thus retains both its power and its impotence: hard to rebut, but also hard to go along with.

We can imagine that not being so. Suppose some possible beings develop the kind of commonsense epistemology possessed by normal humans—the usual concepts of belief, knowledge, justification, reason, evidence, etc., along with the usual distribution of these concepts. They believe, and take themselves to know, various truths about their environment, other minds, the past, the future, etc. But also suppose that at the very outset skepticism starts to rear its head—it comes with the territory. Skeptical possibilities become widely entertained, and not just in university departments. Children start to bring them up, spontaneously and nervously, around the age of ten after a few blissful years of epistemological complacency. People quickly realize there is something seriously amiss with their assumptions. It is rather like starting life with superstitious beliefs and then soon discovering science. We would expect some major revisions of opinion, on pain of irrationality. Maybe some diehards will try to cling to their earlier views, but most will capitulate to reason, accepting that they are really notcertain that there is a table there, or that they are not brains in a vat, or that other people have minds. They might well also agree that such beliefs are not even adequately justified and are not genuine instances of knowledge. They accordingly cease to talk and think this way—as people outgrow superstition, religious dogma, and prejudiced politics. Skepticism is given its due; earlier opinion is discarded. One can be brought up to believe the tenets of a particular religion, but it is within one’s power to abandon those tenets under cogent criticism—and so it might be for one’s “epistemological religion”. And it is not as if you will go to hell if you discard your callow epistemological dogmas.

Or consider this possibility: a group of beings holds to commonsense epistemology for thousands of years with nary a skeptical thought among them. No one has so much as thought of skepticism, so there isn’t any pressure for revision. Children never wonder about what colors other people see, or ask if it’s all a dream, or how we know that the future will resemble the past. Then a particular individual, call her Helena, through some quirk of genius, comes up with skeptical arguments, which (we are supposing) are thoroughly convincing. Helena publishes these arguments in a scientific journal and they reach the public via global press coverage (think Einstein on relativity). Headline: Scientist Discovers We Don’t Know Anything. It is conceivable that our beings will accept the findings in question, as people have accepted other earth-shattering discoveries (species evolved by natural selection, the earth moves, we are not the center of the universe, slavery is wrong). They thus revise their epistemic belief system to fit the new ideas, declining to throw around words like “certain”, “know”, and “justified” with the abandon of yore. It becomes part of received opinion that these words don’t apply as widely as was believed heretofore, maybe applying only to one’s knowledge of one’s own mental state. So late-onset skepticism could have the same efficacy as early-onset skepticism; the mere fact of arriving late on the scene doesn’t imply that skepticism must be resisted. It is just that epistemic error has been around for a very long time. So why don’t we fit either of these models?

It is an empirical question when skepticism first arose for humans. We can safely assume that it wasn’t coeval with the onset of epistemic concepts and their associated beliefs: humans didn’t discover skepticism at the precise moment they began to deploy epistemic concepts, or a short time thereafter. We know that skepticism was much discussed in ancient Greece, but that must post-date by thousands of years the existence of commonsense epistemology. So we would expect some inertia about abandoning this aspect of ordinary belief. But such inertia didn’t stop other ancient canards from going extinct. Would humans have found it easier to let skepticism have its way if it had cropped up later in history, as in my second scenario? It might be argued that skepticism has grown stale for us and thus has lost its initial sharp edge; if it had been discovered at the time of the scientific revolution, it might have had more potency. But this seems implausible: it would still have encountered stiff resistance if discovered in 1680 or 1952. Why? It is conceptually possible for there to be beings who accept its urgings, so why are we so intransigent? It would be different if the skeptical arguments were simply fallacies and follies, easily defeated and defanged, but (we are assuming) that is not so. So what is going on here? Why are we so internally divided on the subject, schizoid almost? Why do we accept the force of skepticism and yet do nothing about it, even when we are quite self-conscious about our position? Why the psychological split?

I have a theory. Consider perceptual illusions such as the Muller-Lyer illusion: these are products of our epistemic faculties—they purport to represent aspects of the world, inviting belief, and offering justification (i.e., how things seem). Yet they are false: those lines are not really unequal in length. The perceiver need not know this and so may form the belief that the lines are not equal. This counts as a piece of commonsense perceptual epistemology. We can imagine people being under this illusion for centuries, never realizing that it is an illusion. Or consider the moon illusion: people might really believe that the moon shrinks as it rises over the horizon into the night sky. Now some scientist points out that these are indeed illusions—things seem that way but they are not really that way. Some people may persist in their earlier beliefs in the face of compelling evidence to the contrary, but most will come to accept that they were wrong—they have been under an illusion. But there is no corresponding change in their perceptual responses: it still looksto everyone as if the lines are unequal and that the moon shrinks. The perceptual system is not penetrable by outside information; it is “encapsulated”.[1]It is modular, stimulus-dependent, and bottom-up. No amount of reasoning, no matter how cogent, can prevent this system from mechanically delivering its standard output. It is, we might say, impervious to reason—a kind of reflex that we have to live with even when we know it is leading us astray. You might have very good reasons for suppressing your patellar reflex, but find it impossible to do, given the way your nervous system is wired; well, the visual system is like that, sublimely indifferent to higher rationality. From this we may infer causal isolation: central beliefs cannot cause the visual module to vary in its mode of response. Such beliefs are quite inefficacious when it comes to controlling vision. So we evidently contain two sorts of informational system that are insensitive to each other (the visual system can’t usurp the central cognitive system either). We thus arrive at a dual-system epistemic psychology. The two systems function autonomously, have a different ontogenesis, and may even employ distinct sorts of mental representation; no doubt they also have different neural substrates. They co-exist and can interact but they don’t mingle—one has no veto power over the other. Sometimes they hardly seem to communicate with each other. We might say that the visual system inclines one to believe what its output (a visual impression) suggests, but this inclination doesn’t prevent one from fully accepting that the facts are otherwise. The result is an oddly ambivalent state of mind, which accounts for the fascination of such illusions: on the one hand, you are inclined to believe what your senses tell you, but on the other you firmly reject their intimations. If someone were to tell you that all this illusion stuff is just a hoax thought up by manipulative scientists—the lines really are unequal and the moon really does shrink—you would be tempted to respond, “I knew it all along!” It is hard to accept that your visual system, otherwise so reliable, should so cruelly deceive you—as if you have a little evil demon living inside your head. As it is, however, you conclude that the scientists are right and your visual sense is wrong—while all the while your senses stick to their own version of things. Theywill not be moved.

My theory, then, is this: our commonsense epistemic system is also an autonomous module separate from the system that trades in skeptical arguments. The commonsense system (“folk epistemology”) pre-dates the reflective skepticism-involving system and is largely independent of it. We started by describing ourselves using epistemic terms at some point in human evolution well before written language and sophisticated culture developed, probably as a result of an innate faculty, and only later did human thought begin to reflect upon itself and issue criticisms. Just so, human vision evolved before science and objective measurement, only later becoming subject to rational criticism, but unable to respond to such criticism by altering its mode of operation. Thus skepticism failed to penetrate the cognitive system that pre-existed it. Put simply, people reflexively apply epistemic concepts to themselves and others, but these applications are independent of higher-order reflection of the kind employed in skeptical arguments.[2]They are encapsulated, automatic, and hard-wired. It is as if we are under the illusionthat we know: that’s how we seemto each other. I seem to know many things about the external world, other minds, etc., but skepticism teaches me that this is an illusion, exposed by consideration of our true epistemic situation.[3]The hamster may be under a similar illusion and be equally impervious to skepticism (if the hamster could understand skepticism)—precisely because it is programmed to accept its natural perspective on things. We go around the world representing it (wrongly, I am assuming) as containing knowledge, justification, certainty, and evidence, by courtesy of our innate epistemic endowment; but skepticism can make no inroads into this system, despite its superior wisdom, because the system is encapsulated and largely oblivious.[4]Thus we have a dual epistemic architecture: a primitive quasi-reflexive uncritical system, and a more sophisticated reflective critical system. The former is reluctant to take orders from the latter, as an adolescent doesn’t listen to his elders and betters. These faculties have different developmental schedules and neural implementations, and they might even differ in their coding properties and mode of operation. It would be possible to have the former without the latter, as presumably children are for some time in this condition. This would explain our divided epistemic self, our ambivalence, our schizoid tendencies, and our confusion. The commonsense faculty is a lot more ancient and primitive, a holdover from simpler times (and look how much illusion and error has been alleged by contemporary science!); the skeptical line of thought is something superadded, a product of late human culture, by no means integral to what preceded it.[5]No wonder it has so little impact on its set-in-its-ways predecessor! But we mixed-up humans contain both systems and so have to live with their quarrels: we are aware of what we are inclined naturally to think andof what our reflective reason says about those inclinations. We want to attribute knowledge, but we are cognizant that this attribution is questionable. We are caught between these two judgments—as we are caught between the conflicting claims of perception and cognition. This is why skepticism is psychologically peculiar: in it we are witness to our own psychological plurality—the fact that we are an assembly not a unity. We suffer from internal conflicts, no doubt with an evolutionary basis. Our faculties don’t always fit harmoniously together. This is a familiar thought for our emotional nature, but the same is true of our cognitive nature, as the case of perceptual illusion so vividly illustrates. I have suggested that our attitude to skepticism has similar roots. One faculty tells us that we know; another says not so fast. The former persists in its ways despite the superior wisdom of the latter.



[1]I am here following Jerry Fodor inModularity of Mind(1983).

[2]Here we may be reminded of Hume’s famous response to the skeptic: we can believe skepticism in our study but we lapse back into common sense when we leave it. Thus we have “natural beliefs” and “philosophical beliefs”—each the province of different cognitive faculties. (Contemporary cognitive science is in many ways a reversion to seventeenth and eighteenth century thought.)

[3]To repeat, I am assuming the cogency of skepticism here, not arguing for it; my question is what explains our reluctance, or inability, to take it seriously in our ordinary practices.

[4]The same might be said of the problem of free will: first we believe in it as a result of an ancient cognitive-cum-affective system, then we come to question it because of scientific ideas such as determinism and genetics. Even when convinced we have a tendency to cleave to old ways—thus we can find ourselves both disbelieving in free will and yet unable to shed our commitment to it.

[5]Psychologists have postulated a “theory of mind” module that grows spontaneously in the young child, much as the language faculty does; it is quite unhindered by skeptical thoughts concerning other minds. Those thoughts come later and from a different source (“critical reason”): they make little dent in the earlier module. Thus we automatically view others as having minds, even though we may be intellectually convinced that we have no grounds for this supposition. Similarly, we have a “theory of world” module that pre-dates and resists later skeptical reflections, however unreasonably. If we put the point in terms of organ psychology, it is as if the primitive mental organ keeps pumping out what it is designed to pump out even when the organ of rational thought counsels otherwise. After all, evolution has only a passing interest in objective truth; what matters to the genes is what works (which may, or may not, coincide with the truth). Whether anyone reallyknows anything, or has justified certainty, is not a matter of great concern to evolution.


Ideas of Time

Ideas of Time



It is well known that Einstein was influenced by Hume and Mach (who was also influenced by Hume). In particular, his treatment of simultaneity was influenced by Hume’s discussion of ideas of time in the Treatise. So it might be useful to revisit that discussion to see how well it holds up under scrutiny. Not surprisingly, Hume applies his general theory of ideas to ideas of time, particularly duration: he maintains that our ideas of time derive from our impressions of time. How we conceive time is fixed by how we perceive time. The concept “copies” the percept. Thus we read: “The idea of time, being derived from the succession of our perceptions of every kind, ideas as well as impressions, and impressions of reflection as well as sensation, will afford us an instance of an abstract idea, which comprehends a still greater variety than that of space, and yet is represented in the fancy by some particular individual idea of a determinate quantity and quality”. He asserts: “Nor is it possible for time alone ever to make its appearance, or to be taken notice of by the mind”. Accordingly, “wherever we have no successive perceptions, we have no notion of time”, so that time can only be “discovered by some perceivablesuccession of changeable objects”. Again: “The idea of duration is always derived from a succession of changeable objects, and can never be conveyed to the mind by anything steadfast and unchangeable”. So the idea of duration is always and necessarily that of a perceivable succession of changes in objects and cannot arise without such perceptions. This, as Hume points out, directly follows from his copy theory of ideas, given that we only have impressions of succession not of pure duration. As he says, we have impressions of time only in the form of relations between events—ordering relations. We perceive time passing byperceiving change occurring. So our concept of time is just the concept of such change. For example, we see physical changes in clocks and thereby infer that time is passing: there is no more to our concept of time than what we observe inside and outside.

It is easy to see how this conception of temporal concepts could lead to radical conclusions about simultaneity. If the concept of simultaneity arises purely from impressions of simultaneity, it will turn out to be relative, since what seems simultaneous to one observer will not seem so to another; this is evident from such simple cases as the time lag between impressions of lightning and impressions of thunder, which varies with distance. The concept of absolute simultaneity thus turns out to be meaningless under Hume’s theory of ideas once we take different observers into account. The same is true of duration, since different perceivers will have different rates of perceived succession.  In fact, Hume operates with two principles in the Treatise: the copy principle and the principle that what is not contained in an idea so derived is empty. It follows from both together that time itself must conform to our impressions of it—it has no nature independent of such impressions. We thus reach the conclusion that there cannot beduration without the perception of change—the thing itself not just the idea of it. Starkly stated, there is nothing more to time that how it seems to us in perception, for we have no conception of it independently of our perception-derived ideas. Given this philosophy of time, it is not surprising that Einstein motivates and justifies his conception of time by reflecting on the observation of clocks, since these afford our empirical basis for thinking about time. Anything else would violate Hume’s empiricist strictures. Newton’s absolute conception certainly does, since it corresponds to nothing in our experience—no one has ever had an impression of an absolute infinite time independent of change. As Hume says, summing up his position: “The ideas of space and time are therefore no separate or distinct ideas, but merely those of the manner or order, in which objects exist”. It is thus “impossible to conceive either a vacuum and extension without matter, or a time, when there was no succession or change in any real existence”. It is a short step from this to Einstein’s ideas about the relativity of simultaneity and the corollaries he draws from that.

The trouble is that this is all immensely dubious. I will merely list the many objections that have been and can be made against Hume’s theory of ideas. First, there was the missing shade of blue, a straight counterexample to his copy theory. Second, ideas are singular and abstract whereas impressions always include many qualities and are concrete. Third, animals have impressions but don’t generally have corresponding ideas, so the step to concepts cannot consist in an impression leaving a mark in memory. Fourth, elements of images in the imagination are not functionally identical to concepts. Fifth and connected, concepts join together to form propositional thoughts, but impressions don’t (or copies of them): concepts compose but impressions merely co-exist or succeed. Sixth, even images are not really copiesof impressions but have a nature of their own, differing in many ways from impressions.[1]Seventh, Hume relies heavily on the argument that he can think of no other theory of the origin of ideas, but this argument is weak. What about the rationalist theory of innate ideas? What about the theory that ideas are linked more to language than to perception, corresponding to the word-like elements of the lexicon (plausibly regarded as innate)? What about the possibility that we just don’t know the origin of ideas? Better to accept ignorance than push a manifestly inadequate theory. Eighth, what justifies the inference from ideas to reality? Just because our ideas can only have a certain sort of content, why does it follow that reality must reflect this content and contain no more? Isn’t that idealism? Ninth, as Hume recognizes, the very existence of the standard debates about space and time apparently shows that we do have ideas of absolute space and time; it is just that we are arguing about which theory is true.[2]Don’t I have the concept of other minds even though my impression of other minds is purely of the bodily behavior of others? I know quite well what I am talking about; I just don’t know whether other minds really exist. Tenth, concepts are nothing like memories, which they would be if Hume’s theory were correct (they don’t fade or mutate like memories). Eleventh, Hume often conflates ideas of things with ideas of impressions, but most of our ideas are not of impressions: I have an idea of a square thing, but this is not the idea of an impressionof a square thing. The latter idea seems like a reasonable consequence of having an impression, but why should the former be so derived? That would be moving quite beyond the impression itself. Finally, a concept does not present itself to introspection as impression-like: it is far more elusive, hidden, and obscure. We can’t just introspect and report what a concept is, as Hume seems to assume. The theory of concepts is actually quite undeveloped and highly controversial, with Hume’s empiricist theory just one theory among others; it lacks the self-evidence he cheerfully takes it to have.[3]

So Einstein’s reliance on Hume was reliance on a very frail reed—indeed, I would say, a complete non-starter. If this was his basis for rejecting classical notions of time and promoting his own radically revisionary opinions, then it was totally wrongheaded. Humean concept empiricism is not a sound foundation for constructing a theory of the physical world. Nor do I see how Einstein’s arguments for the relativity of simultaneity can survive without such reliance, as inspection of his writings reveals (the Hume-inspired positivism is quite apparent). One is inclined to conclude that bad philosophy leads to bad physics. Certainly, Einstein’s physical theory derives no support from the underlying philosophy of time. It looks as if a false philosophical theory of ideas has led to a bizarre physics full of paradox and puzzlement. The question is whether it is possible to detach STR from the erroneous philosophy that led to it. I can’t see how, but I am no physicist.[4]


Colin McGin

[1]See my book Mindsight: Image, Dream, Meaning(2004).

[2]Consider this remarkable passage: “If it be a sufficient proof, that we have the idea of a vacuum, because we dispute and reason concerning it; we must for the same reason have the idea of time without any changeable existence; since there is no subject of dispute more frequent and common. But that we really have no such idea, is certain. For whence should it be derived? Does it arise from an impression of sensation or reflection? Point it out distinctly to us, that we may know its nature and qualities. But if you cannot point out any such impression, you may be certain you are mistaken, when you imagine you have any such idea”. Hume’s hectoring use of italics here does nothing to bolster the entirely question-begging character of his rhetorical questions. On the face of it, the existence of the disputes in question provides a simple proof of the falsity of his theory of ideas: how can we be certainwe lack certain ideas when for all the world we are discoursing about them? A rationalist, say, would be unimpressed with Hume’s confidence. What is certain is that we have the ideaof such ideas!

[3]I do agree that Hume’s theory is apt to make an impression on impressionable young minds (if the puns be excused), and he is no doubt a formidable polemicist; but really his empiricist theory of ideas (concepts) is grossly implausible. I wonder whether the young Einstein knew other philosophers’ work as well, particularly the rationalist tradition. He would not be the first or last young person to fall under Hume’s spell. (By the time of the EnquiryHume himself had seen through his earlier exaggerations and doesn’t revisit the topic of time.)

[4]The influence of logical positivism on physics was, and still is, considerable, and it can be difficult to disentangle this influence from purely empirical considerations.


Physiology of Mind



Physiology of Mind


Physiology lacks a philosophy to call its own. There is no philosophy of physiology to speak of. Perhaps this is because physiology is a sub-discipline of biology and we already have a philosophy of biology. But this neglects the possibility that physiology works with concepts and theoretical constructions specific to itself, and these require philosophical treatment in their own right. Here is how the OEDdefines “physiology”: “the branch of biology concerned with the normal functions of living organisms and their parts”. As always, this definition is worth dwelling on. Physiology is the science of the functioning of living organisms and their component parts, such as the heart, the kidneys, and the brain. The word “function” here has two separate connotations: it refers to theoperationsof organisms and their parts, and it refers to the purposeof those operations. How do organisms work and why do they work that way? Thus the function (purpose) of the heart is to circulate blood, and the way this purpose is achieved is by acting as a pump with a certain structure and mode of action. Physiology must first identify the end an organ serves and then explain how that end is achieved by the organ in question. And what is an organ? The OEDhas this: “a part of an organism which is typically self-contained and has a specific vital function”. An organ is relatively autonomous in its operation and its function is specific and vital (though not necessarily a matter of life and death). So physiology is concerned with organs that have their own identity and which have a dedicated specific purpose not shared by other organs. The central concepts of physiology are therefore life, purpose, functioning,andorgan.Notice that no restriction is made to the body as opposed to the mind (this will be relevant later), nor are genetics and evolution invoked.

Venturing beyond the dictionary definition, we can make a number of other observations about physiology (the science and the reality). First, there is a division of labor among organs: some do one job and some do another (nineteenth century physiologists compared the body to a factory). Second, function and structure are intimately connected: whatever the function of an organ is, it must have a structure that suits it to perform that function; and physiology as a science must characterize this relation. We may think of it as a fittingrelation: it resembles the way artifacts fit their function—they must be physically capable of performing it. Thus physiology (functioning, activity) must dovetail with anatomy (structure, architecture). Third, although organs are sharply differentiated, they must be integrated—because they have to work harmoniously together. Rogue organs do nobody any good. They need some sort of central command or supervision (here is where the brain comes in handy). Fourth, and connected, organs belong to organ systems, forming complex organs—consider all the organs that go into digestive systems. These must be integrated together, but they also need to be integrated with other organ systems. Accordingly, there is a hierarchical structure to physiology: systems, subsystems, individual organs, components of such organs, etc. Fifth, there is a normative aspect to physiology: that is, we have the notions of health and disease, normality and pathology. This is because of the teleological element: organs are healthy or defective according as they achieve their purpose, which is to preserve life (which we assume is a good thing). Sixth, just as the organism exists in an external environment which it must negotiate, so the several organs of the body exist in an internal environment; and in both cases adjustment and accommodation are required. Here is where homeostasis comes in—the need to keep the internal environment stable and contained within certain limits (temperature being the most obvious parameter). The organism exists in a physical environment and one that contains other organisms; the organs exist in a chemical environment and one that contains other organs. There is a nesting of environments. The organism has a certain Umwelt, but so does the individual organ. This point gives rise to the seventh observation: organs, like organisms, are input-output devices. Something goes in and something comes out. Often the organs function as a conversion device—as with the lungs and stomach. All organs need nutrients to be absorbed in order for actions and processes to be powered. The components of the body are not isolated and cut off. Thus the organs need to contain interactive mechanisms—devices that make things happen, often of elaborate design. The system is intricate and interlocked, though differentiated and distinct. Eighth, the organs have a genetic basis, a distinctive embryogenesis, and an evolutionary history; they are certainly not “acquired” by means of interaction with the environment. The tabula rasais a very bad model for physiology. The heart is as hard-wired and pre-determined as any nativist could wish. Ninth, despite the manifest variety of organs, there are certain physiological universals, particularly pertaining to cellular structure: all organs are made of cells, though the cells typically differ histologically. Thus macro-physiology is highly heterogeneous, while micro-physiology is quite homogeneous (the cell with its nucleus, membrane, and mitochondria). As it were, the atoms are alike, but the objects they compose exhibit considerable variety, according to their specific jobs. Tenth, we can, for any organism, make a list of its characteristic organ systems, which serve to fix its phenotype; these may overlap with other species or may be unique to the species in question. By my reckoning, human physiology contains the following organ systems: digestive, respiratory, sexual, circulatory, immune, motor, postural, sensory, protective, and mental (with many subdivisions: see below). So the magic number is 10—other species may well have less, though in general this number seems to apply to all but the simplest organisms. Thus evolution needed to produce 10 organ types that work together to keep an organism alive. Subtract any of them and you tend to get a dead organism. Physics and chemistry have their types of particle; physiology has its types of organ. The raison d’etreof each is its contribution to maintaining life.

Before I turn to applying this conception to the mind, it will help to talk in some detail about specific organs, so that we have a concrete point of comparison. The heart is composed of two types of cell, known as cardiomyocytes and pacemaker cells, which have different functions. The former enable muscular contraction and are cylindrical in shape. They have high mitochondrial density that enables them to produce large amounts of ATP, which makes the heart resistant to fatigue. Heartbeats are caused by the shortening and lengthening of fibers. The gross anatomy of the heart divides it into the atria and the ventricles, chambers that receive blood and pump it out, respectively. The tissue of the heart is a type of muscle tissue. By pumping blood the heart serves its purpose of circulating blood throughout the body to maintain organs and perform other functions. The functioning of the heart is closely linked to the respiratory system. The kidneys, for their part, have a different shape (more like a large bean) and are made up of different cell types called nephrons. They process liquids and expel urine. The liver is a large organ that contains hepatocytes and endothelial cells, boasts two lobes, is adjoined to the gallbladder, and performs a variety of functions related to digestion, also secreting bile. Diagrams of these organs can be made and they have a distinctive macro anatomy and microanatomy. Structure is suited to function; function is specific; there is input and output; there are links to other organs. This is the stuff of physiology as defined above. It goes beyond more general biological concepts, such as genotype and phenotype, natural selection, species, evolution, reproduction, and so on. Physiology is primarily concerned with the concept of an organ, understood in the way outlined—structure, role, purpose, operation. As remarked, this concept is not conceptually tied to the body or to the concept of the physical: it could have turned out that organisms house non-corporeal organs (as was supposed for the elan vital), so long as these entities fulfill the general abstract definition of an organ. If cavities in the body perform a role analogous to meaty tissue, then they too would count as organs, since they aid life. Or a Cartesian biologist might postulate an immaterial organ responsible for circulating the blood, on the (mistaken) assumption that such an impressive and important feat could not be performed by mere matter and needs the help of the ethereal. Most significantly for our purposes, nothing in the definition of physiology requires that the mindnot count as an organ possessed by an organism. Hence we have the idea of a physiology of mind—a science of mental organs.[1]That is, psychology is a branch of physiology. Not just a branch of biology, but a branch of the branch of biology called physiology. Nor is this conception in any way precluded by the etymology of the word “physiology”, since this word derives from a Greek word meaning simply “nature”. Nothing specifically physicalis entailed (whatever exactly “physical” is supposed to mean).[2]

The basic idea is far from novel (Chomsky has been speaking of “mental organs” for decades and comparing them to bodily organs). What I want to do is apply the conception developed above in an explicit theoretical way, so that the mind emerges as fully and properly physiological–not metaphorically but literally. The mind really is an aspect of the physiological constitution of the organism, animal or human. It is literally a collection of physiological organs. Recall the dictionary definition of “physiology”: “the branch of biology concerned with the normal function of living organisms and their parts”. Surely it is obvious that the mind of an organism is part of its normal function: the mind has a function and this function is normal. Or rather, the mind is made up of faculties (“organs”) that have a function and which function in the life of the organism. The sense experiences of bats, say, have a function and they function in the life of a bat—they have a purpose, a nature, and a mode of operation. We refer to the senses as sense organsfor a reason—they literally are organs. But they are not purely bodily organs—they are psychophysical organs; they have both a mental and physical aspect. Their having the former aspect in no way disqualifies them for the title “organ”. Not that it matters whether the word “organ” fits as a matter of common usage; from a theoretical point of view, vision (say) is as much a vital biological property of an organism as the stomach. There is no principled or interesting dividing line here. Animals have organs in their bodies and they have organs in their minds (or partly so). Again, the dictionary definition of “organ” confirms this topic-neutrality: an organ is just part of an organism that is “self-contained and has a specific vital function”. It would be pointless to quibble over the word “part” here on the grounds that mental faculties are not really partsof an organism; we could easily rephrase the definition by using “aspect” or “property” or “trait”. The interesting question is to what extent mental organs share the characteristics I attributed to organs in general, for that is what determines whether the concept of the physiological is apt. So: is the mind organ-like?

Consider the language faculty. There is much controversy on this subject but I propose to cut through all that and adopt a specific perspective, roughly that developed by Chomsky. I will accordingly say that language is an internal system (with an external expression) that consists of rules of computation and a lexicon of word-like elements. A grammar specifies the structure of this system and takes a generative form. The grammar is innate and modular. Sentence structure can be represented by tree diagrams. The grammar outputs infinitely many possible strings on a finite basis. The internal system connects to sensory systems (typically hearing) and to motor systems (typically speech mechanisms), as well as to cognitive processes such as logical reasoning. Given this general conception, it seems evident that the language faculty counts as an organ and hence as an element of human physiology. It has a complex internal structure, relatively specific, with connections to other mental organs, an innate basis, and even its own mode of depiction (those tree diagrams). If we ask what its function is in the life of the organism, the answer is not far to seek: it serves either as an aid to thought or as a means of communication (depending on your view of the purpose of human language). In either case (or in both) language performs a vital biological function in the life of the human organism; you are at a comparative disadvantage without it. It contributes to reproductive fitness. It propagates the genes. It is also an input-output system: sensory inputs, including speech, and motor outputs, also vocal (sometimes gestural). You report what you see and hear and you talk about what you think and feel. So it is connected to other organs or modules or faculties, and hence operates in its own specific internal environment (consider internal speech). It is differentiated yet integrated, self-contained yet embedded. Thus it counts as part of human physiology—our nature as living things, our phenotypic identity. Essentially, it has a certain functional architecture that fits into the life of a particular species—a compositional structure and characteristic mode of operation. As plants engage in photosynthesis as part of their mode of living, so humans engage in linguistic synthesis as part of their mode of living: they put sentences together by following certain procedures and this product aids them in life. And this faculty can exhibit signs of ill health and disease if it fails in its purpose, as other organs can: thus aphasia and the various types of language pathology. The language faculty is not supposedto issue in nonsense or grammatical error, yet it sometimes does—it is then not working according to its function. There is right and wrong, good and bad, well-formed and ill-formed. Physiology is inherently vulnerable to breakdown and malfunction, and language is no different. This is a logical consequence of having a biological purpose.

Much the same can be said about other commonsense mental categories: perception obviously, but also memory and reasoning. I won’t discuss these in detail; it is fairly easy to see how the story will go. There will be a specification of the organ’s function and a description of its enabling structure–the former obvious, the latter less so. Then we will need to locate it in a wider system, characterizing its inputs and outputs, and its internal environment. There will be specific architectural details, as well as some shared properties (constituent structure looks like a universal). We might be able to draw a map of the mind relating its various components—a full mental anatomy.[3]No doubt there will exist a physical and chemical basis to the mental organs at a deeper level of analysis (which will not replace the higher levels), and a cellular substrate. The important point is that we are not now engaged on a completely different enterprise from that of traditional physiology; we are merely extending that enterprise. The same theoretical framework is employed, but now applied to the physiology of mind.[4]A stubborn residual dualism will be resisted in favor of a more unified vision of the organism. The mind will be granted a lot more internal structure than on certain traditional conceptions, which insist on a radical discontinuity between the study of the body and the study of the mind (the body jammed with structure, the mind merely a blank nothingness). The body turned out to have a lot more internal structure than early physiological inquirers suspected; the mind will likely reveal a lot more structure than similarly benighted theorists assume (and has already done so). Framing the questions in physiological terms provides an apparatus for inquiry that encourages the same kind of open-minded exploration. Approaching an alien species, we would expect to discover its internal bodily organization—its organs and their processes—but we should adopt the same attitude towards its mental organization. The most basic principle of physiology, whether of the body or the mind, is that nature has made organisms to consist of differentiated but integrated organs serving specific functions. There is no such thing as blank and homogeneous physiology.[5]


[1]Kant speaks of the “physiology of understanding” in relation to Locke’s project in the Essay: this was a good insight on his part. See the preface to Critique of Pure Reason.

[2]The physiological conception I am advocating is not to be confused with the perspective of so-called neuroscience. There is nothing reductionist about my proposal and its preferred descriptive vocabulary is not the same as that of the brain sciences. That vocabulary is geared to the type of cell composing the brain (neurons) as well as the gross anatomy of the brain. By contrast, the vocabulary of physiology abstracts from this detail and talks of organs, function, structure, life, and organic systems. This talk is topic-neutral and in no way presupposes a “physicalist” view of the mind (whatever that might be).

[3]It is an interesting question whether consciousness counts as an organ in its own right or whether it is a quality possessed by various mental organs. I suspect the latter to be true, but in either case it would be a physiological phenomenon, perhaps analogous to the smoothness of bodily organs, which is shared by many such organs.

[4]Let me put in a word for the “second brain”, that neural structure in the gut that regulates digestion. Assuming that there are mental correlates to its operations, we could postulate a “second mind” that harbors its own set of mental organs (see my “The Second Mind”, in Philosophical Provocations, 2017). I suspect many people will be more ready to grant physiological status to this lowly mind than to the more familiar mind that engages in logical reasoning and artistic creativity. But really the “head mind” is no less organic than the “gut mind”.

[5]Even a physiology of an immaterial Cartesian substance, if such there could be, would deal in organs and their activities, since the mind is made of a number of interacting faculties that need an operational structure. The immaterial mind would not be a formless nothing any more than the body is. Perception, thinking, language, memory, emotion, and volition will all require specific configurations of the immaterial stuff in which the mind is held to reside. And there will be the same questions about purpose, mode of operation, etc.


The Motion-Body Problem


The Motion-Body Problem



“For I would fain know what substance exists that has not something in it, which manifestly baffles our understanding. Other spirits, who see and know the nature and inward constitution of things, how much must they exceed us in knowledge?” John Locke, Essay Concerning Human Understanding, Book 4, chapter 3


Mechanism succeeded scholasticism as a theory of motion in the seventeenth century, to be displaced by Newton’s gravitational theory in the eighteenth. By postulating a force that acts at a distance Newton abandoned the restriction to contact causation, thus departing from commonsense physics. This theory was widely regarded as ”occult” (including by Newton himself) and as a regrettable recrudescence of scholasticism. Newton’s equations described the laws of motion but did not identify its cause, about which he declared himself ignorant. Mechanism had promised to render the world intelligible, but Newton’s mysterious force gave up on that ideal, resting content to offer mathematical predictions. So matters remain to this day (despite Einstein’s innovations). This is a familiar story, which I will not re-tell[1]; but it is worth dwelling on how strange Newton’s gravitational theory is, because we have become inured to it over the years. We don’t normally observe planetary motion with our own eyes, but if you watch a graphic representation of it on film it strikes you as a kind of bizarre celestial ballet, in which massive bodies dance around each other as if mesmerized. Planets and moons orbit other bodies without apparent influence, describing precise trajectories, as if of their own volition. An invisible hand seems to guide them. Newton tells us that the cause of this ballet is a force called “gravity”, but there doesn’t seem to be any forcinggoing on—no pushing and shoving. We are informed that the motions involved are proportional to the mass of the bodies (as well as their distance from each other), but why the quantity of matter in a body should affect its power of remote control is not explained (why not volume instead?). It’s all a lot to swallow. And nothing further is said to render things any clearer. On the face of it we are presented with celestial choreography that defies understanding, to which various labels have been applied by stipulation (“force”, “gravity”). It looks like a machine without any internal rationale or intelligible design–a happy confluence, a cosmic magic trick. Evidently there is some sort of attraction going on, but the nature of the attraction remains opaque.

Suppose you were interested in other sorts of motion, say the motion of leaves in the wind. You don’t know that the air is composed of gases with molecular components that make impacts on leaves invisibly. Some bright spark (a Mr. Newby) suggests that these motions are the result of a force emanating from another galaxy, which he chooses to designate as the “intergalactic force”: the force operates over vast distances instantaneously (or at the speed of light) and obeys an inverse square law. You might well be skeptical of such an extravagant theory, wondering if it is even intelligible. And Mr. Newby’s fancy mathematics, predictive though it may be, would not quell your anxieties. “How is that even possible?” you would think. The assertion that no other theory is in the offing (there is no theory of gases to appeal to) would not assuage your worries. But isn’t this essentially the predicament we are in with respect to Newton’s theory of gravity? A mysterious force operating over vast stretches of empty space, correlated de factowith mass, just seems like a preposterous speculation. It is no wonder that theorists of the time felt the need to introduce ether for it to operate through, in a halfhearted attempt to resuscitate mechanism: at least that would restore proximal causation. What if a follower of Mr. Newby (a Mr. Carter) sought to extend the theory to cover psychophysical interactions that involve immaterial substances: Mr. Carter believes that immaterial minds exist and that their motions are governed by the same force that applies to leaf movements etc. Clearly, he reasons, minds move around when bodies do, and this requires explanation—so Mr. Carter posits a force operating from afar that ensures such movements, thus preventing minds from being left behind when bodies move. Even followers of Mr. Newby might be skeptical of Mr. Carter’s radical departures from commonsense, but the latter ingeniously argues that such causation is no more occult than what is already accepted. It is simply a fact, he insists, that immaterial minds are also subject to the intergalactic force—the nature of the substance is irrelevant to its powers of motion under the influence of remote objects. Granted this is not intelligible to us, but neither is the prevailing theory of wind-driven motion—or planetary motion for that matter. After all, once you have accepted remote causation through a vacuum in your theory of planetary motion, why not extend this idea to other sorts of motion in the absence of anything better to say? And if unintelligibility is no objection, why not go the whole hog? Isn’t it simpler to accept that all causation is at-a-distance once it is has been admitted in one area? The only objection to it can be the existence of other better theories, not the intrinsic character of this theory. And it is surely true that Newton and company would leap at the chance to dispense with action-at-a-distance if they could. Accepting that theory is a burden not a joy. If only mechanism had worked out!

Now imagine some gigantic creatures marauding around the universe: they are bigger than a galaxy by quite a bit. Their senses are somewhat dull, so a galaxy like the Milky Way looks rather the way a golf ball looks to us. In fact, they use galaxies as pieces in their games. They are still tiny compared to the universe as a whole and know of another species ten times their size far away (fortunately). They are interested in the science of galaxies and form theories of them. Their theory is that galaxies are made of things called “stars” and “planets”, which move about according to laws. These objects they refer to as “particles” and they admit that no one has ever seen one of these invisible theoretical entities. Their epistemic relation to the giants is like the epistemic relation of atoms to us. At some point in their history a towering genius suggested that these particles move as a result of a force called “gravity”, which the said genius characterized much as Newton did. Let’s suppose they have never seen any movements governed by this mysterious force but accept it merely on theoretical grounds. Wouldn’t that theory strike some of them as pretty far-out? How can the particles move in relation to each other by dint of an occult influence operating over empty space? Mechanical influence they understand (they hit galactic golf balls all the time), but this postulated “gravity” business strikes them as baffling. It seems to them suspiciously like a type of telepathy. Surely the scientists can come up with something better than that! Admittedly, the universe is a strange place, and much remains mysterious, but it is hard to accept that matter is made of objects that affect each other at a distance without any mediating medium. Their reason recoils at the idea. Perhaps there are things the scientists are missing—maybe they lack the right concepts to make sense of reality. Their microphysics clearly needs an overhaul.

My purpose in rehashing and dramatizing these concerns is to draw an analogy to the classic mind-body problem. For the structure of both problems is remarkably similar: both involve an explanatory question and an array of options that fail to carry conviction. In virtue of what do things move? In virtue of what do things have minds? These questions are not easy to answer and they spark intense controversy. An extreme response is to deny that the problematic phenomena exist at all: there is no motion and there are no minds. These things are apparent but not real—as with Zeno and the eliminative behaviorists. There is nothing real to worry about. Then we have the reductionists: mind reduces to matter, and so does the power of motion. Mind is really nothing but a congeries of correlated brain states, and motive power is nothing but its correlated basis in objects—mass in the case of Newton’s physics, natural teleological tendencies in the case of Aristotle’s. Of course, the view is implausible in the extreme for motion, since the intrinsic properties of matter are precisely static(though they can be given a dispositional interpretation); but implausibility is not guaranteed to stop reductionists in their tracks (maybe motion is static too from a four-dimensional perspective).[2]Then we have dualism: motion is simply an additional dimension of reality, a brute fact that can’t be explained by anything else. Objects don’t move in virtueof anything in matter—as minds don’t think in virtue of anything in matter. In effect, Newton’s theory is dualist, since it invokes a force as an extra ingredient in the universe existing over and above such properties as extension, mass, solidity, shape, etc.[3]This theory might go along with supernatural infusions, with God serving as the prime mover keeping everything in motion—as he acts as the author of the mental world. Thus we have the idea of “subtle spirits” lurking inside bodies that ground their ability to move and to move other bodies (Newton looked for evidence of these but couldn’t find it). Physics itself turns out to be dualist. It is in virtue of non-material (non-mechanical) properties of material things that gravity works as it does—not in virtue of material properties like mass.

The ether theory operates conceptually rather like panpsychism: just as the mental is everywhere enabling mind to emerge from a material (sic) basis, so matter is everywhere (in attenuated form) enabling motion to “emerge” from spatially remote objects. Pan-materialism is the elixir that allows bodies to influence each other across space (compare Descartes’ plenum). Thus miraculous emergence is avoided and explanatory obligations discharged (allegedly). Mysterianism also has its counterpart: gravity (and hence motion) arises from matter because matter houses unknown properties that enable the apparent miracle to occur. True, matter as we conceive it cannot explain its capacity for motion—hence the eerie feeling we get when we contemplate planetary motion—but matter has a hidden nature that grounds its ability to move. Let’s call this hidden nature (relative to our cognitive capacities) G: then we can say that things move in virtue of G. G is an unknown quantity, possibly as a matter of principle for creatures like us. In effect, this was Newton’s position, since he thought that gravity had a cause, just a cause we can’t discover—or at least haven’t discovered by our most diligent efforts.[4]

Thus the motion-body problem tracks the mind-body problem. It has the same general form and generates the same array of theoretical options. This is not to say that the problems are identical—mind clearly involves features unique to it (subjectivity, intentionality, freedom, etc.): but the structureis much the same. In particular, the thrust towards accepting mystery is common to both: there is evidently something we are missing in both cases, something vital. This might be because of inherent cognitive limitations on our part—or it might be remediable by further theoretical effort (but don’t count on it). The problem of motion was the Great Problem of early modern science, and it has by no means been vanquished; likewise the problem of consciousness (or the mind in general, including the unconscious) is the Great Problem of our age. Both carry the whiff of mystery—I would say, the fact of mystery. We simply don’t know in virtue of what matter moves, as we don’t know in virtue of what matter thinks (feels, senses, etc.). We know that things do move, and we know quite a lot about the laws of motion, but we are clueless about the origin of motion.[5]So the world is not fully intelligible to us in this respect. As Locke says, other “spirits” might grasp the principles involved, but we are fumbling in the dark. It seems extremely doubtful that what explains motion will also explain mind (that would be a truly Unified Theory!), though I suppose nothing can be dogmatically ruled out; but what does seem true is that there are great gaps in our understanding of reality, as Locke conceded.



[1]See Noam Chomsky, What Kind of Creatures Are We?(Columbia University Press, 2016) for a detailed and illuminating discussion of the history of this issue (particularly chapter 4), which forms the background for what I say here.

[2]We might also consider non-reductive supervenience as a theory of the relation between movement and other properties of matter: if two material objects agree in all their non-dynamic properties, they must agree in their dynamic properties. That may be true, but it doesn’t answer the question of howmotion thus arises. Supervenience is not explanation. The same is true for mind-body supervenience.

[3]By contrast, Descartes is a monistic materialist about motion: he thinks it arises from mechanical causes. The so-called physical world is all of a piece for him—basically extension and collision (space itself is rarefied matter). Newton introduces a non-mechanistic element in the shape of gravitational force, thus finding an irreducible dualism at the heart of the physical world. Descartes’ mechanistic monism only falters when we come to mind, while Newton abandons materialism (mechanism) about the non-mental world. Newton, of course, had a strong interest in alchemy and other supernatural matters. We should speak of “Newtonian dualism” as well as “Cartesian dualism”.

[4]What if we claim that matter has an essentially mental nature, as with neutral monism? That would qualify as a hidden property of matter and hence could be the key to its attractive powers. But it is hard to see how this doctrine could make gravity any more intelligible, since “mental matter” would still need to operate across a vacuum at arbitrarily large distances. There seems noconception of matter, no matter how speculative or fanciful, that would render Newtonian gravity intelligible, at least to us.

[5]I have focused on gravitationally induced motion, but the same points carry over to electromagnetically induced motion: this too involves attractive (and repulsive) forces operating in a vacuum over empty space, equally violating mechanism. As Chomsky remarks, we have become used to abandoning world-directed intelligibility in favor of the lesser goal of theory-directed intelligibility (i.e. the theory is consistent and enables satisfactory predictions).


The Limits of Predication





The Limits of Predication



A realist will hold that there may be properties of objects we don’t know about, even can’t know about. Kant holds that the noumenal world consists of just such instantiated properties.[1]Human knowledge is limited and doesn’t necessarily extend to every property of objects. But it is not typically maintained that reality may contain facts that fail to consist in the instantiation of properties of anykind. Indeed, this looks contradictory given that we equate facts with instantiations of properties—and what else could they be? How could reality contain anything that wasn’t the instantiation of a property by an object? From an epistemological point of view, how could there be a conceptual scheme that wasn’t predicative? Surely any representation of a fact will consist of the identification of some object and the ascription to it of a predicate. Even unknown properties are logically ascribable by means of a suitable predicate—perhaps wielded only by God. How can thought be anything other than predicative? So there doesn’t seem room for a position that finds the object-property distinction or the subject-predicate distinction parochial:allof reality must conform to these linked distinctions. Granted we don’t know all properties, but whatever we don’t know is at least a property of somesort; and similarly for objects. Put differently, when Plato discovered the distinction between particulars and universals (or logicians discovered the subject-predicate distinction) he discovered a necessary non-negotiable truth about all possible reality. Every possible world must consist of particulars instantiating properties, however peculiar those particulars are and however alien their properties. The world may be very different from how we think of it in terms of its objects and properties, but that it contains objects and properties is not disputable; here skepticism reaches its limit. It couldn’t turn out that the real world fails to consist of objects and properties (particulars and universals). Similarly, there could not be a conceptual scheme in which nothing is predicated of any object: Eskimos may have ten words for snow and the Hopi have a different concept of time, but in both cases they employ predicative concepts directed towards individual things. Every conceivable conceptual scheme consists of concepts, i.e. mental entities that express general features of objects. So there are no limits to predication, as there are no limits to the object-property distinction. These are as solid and universal as any logical law. The structure of reality is given by the object-property structure and the structure of thought is given by the subject-predicate structure—nothing else is possible or conceivable. There can’t be sectors of reality that fail to conform to these structures. Reality necessarily consists of predicable properties.

That seems like a compelling position, and it puts a limit on how dramatically reality may diverge from the way we normally think of it. The structureof our thought is adequate to every conceivable state of affairs even if the contentof our thought is restricted. Reality can only be constituted in one way, and we possess that way. Things are not so dire as skeptics sometimes make them seem. But on reflection this comforting conclusion begins to look overly optimistic, indeed unacceptably anthropocentric. For how could the contingent facts of human psychology, characteristic of a particular species at a particular point of evolutionary history, manage to encompass every possible configuration that objective reality may assume? Do we think that the minds of other animals possess such universal logical penetration? If we agree that human language evolved quite recently in evolutionary time, and that it forms the foundation of our cognitive abilities, how could it be that it is adequate for every layer or type of reality, reaching across all possible worlds? Isn’t the subject-predicate structure just a feature of our biologically given language faculty, hardly indicative of the way everything must eternally and necessarily be? Why should it apply to the world of subatomic particles even? It didn’t evolve with this part of reality in view. Isn’t it enormous hubris to identify the structure of our thought with the structure of all possible reality? Thus it may be said that reality might well consist of facts, states of affairs, things, or stuff that flout our cognitive structure—that don’t fit the predicative form. This form may apply to the world of the senses, but why should it apply to every part of reality, no matter how noumenal? Why should our concept of a property have such universal sweep? Maybe it is just a hopelessly anthropocentric way to conceive of reality, bequeathed by Plato and imposed on Western thought uncritically. Of course, we can’t say what this reality might be like, since we are limited to the cognitive resources we have, but that is no bar to accepting that our resources may be partial or even skewed. Perhaps all we can do is speak of “the thing in itself” or “the ultimate stuff of the world” or “being as such”, admitting that there is no requirement for the designation of these phrases to fall neatly under the structure embedded in the distinction between objects and what can be predicated of them. This structure may be artificial or superficial or simply not applicable to everything.

This type of radical position is familiar from the philosophical tradition and is not without romantic associations (it is up to us to make reality in our own image!). The world consists of undifferentiated stuff and we impose structure on it by exploiting out predicative cognitive apparatus. Reality is not objectively divided into particulars and properties; we project that structure onto it according to our own interests. The real world is like amorphous dough or a formless cloud or a blank slate or the empty sky; all individuating structure derives from us. The trouble with these metaphors is that they concede the point at issue while claiming to deny it: for dough, clouds, blank slates, and the sky all have constitutive properties that make them what they are. They are not somehow pre-predicative or property-less—those mythical “bare particulars”. We know of nothing in reality like that. There is no infinitely plastic substratum we can point to. But the underlying metaphysical claim is not refuted by the inadequacy of these examples–the claim, namely, that it seems a bit of a stretch (to put it mildly) to suppose that all reality must conform to contingent human modes of thought, even deep-seated ones. Is there a better way to articulate the position? Might there be signs of its correctness already existing within our conceptual scheme? An obvious first thought takes its rise from feature-placing sentences like “It’s cold”. It may be suggested that such sentences fail to predicate a property of any particular, so are counterexamples to the subject-predicate hegemony. That may be true as a matter of grammar, but the point doesn’t cut deep: there is still the property of being cold, and clearly the state of affairs in question involves assorted cold objects. However, the idea that some statements could locate a quality rather than ascribe it to a distinguished object is not without value in the present connection, because it loosens the grip of the paradigm supplied by statements about perceived material objects. Couldn’t there be a world of spatially distributed features?

A different kind of argument might be extracted from quantum physics. Here it may be said that the ontology of discrete locatable particulars instantiating determinate properties is put under pressure. This line of argument is only as persuasive as the underlying physics that it presupposes, and we all know how controversial that is. Still, again, the case provides some inkling of what an alternative view of reality might be like, in so far as we can really understand what is being maintained. And even if we can’t understand it, there is the possibility that reality might not fit the neat structure we habitually bring to bear on it: everything might be a lot messier down there, blurrier, weirder. Do particles really haveproperties in the way macroscopic objects do? Similarly, it might be said that field theory in physics violates the particular-property distinction: fields take intensity values at certain points but there is no objectthat instantiates a certain property. Fields are not locatable particulars, but are spread out indefinitely through space. Again, there are going to be questions about the ontology of fields, but at least this case provides a possible way to think about an alternative conception of the structure of reality.  Then again, we have the view, espoused by Russell, that the subject-predicate form is a relic of the old substance metaphysics, which should be replaced by an event-based ontology. In this ontology we don’t speak of objects (substances) instantiating properties but rather of the exemplification of event types in space-time.[2]This might be thought an alternative to the old Platonic model of a continuing object being hooked up to a shareable universal. Again, there is a question about how far this position departs from the basic object-property distinction and subject-predicate grammar, but it at least purports to offer an alternative conceptual structure. And what about the mind—does it really fit the predicative form? That form surely has its home in the material world of perceived particulars, but it has always seemed strained when applied to the contents of mind. We feel like we are forcing consciousness into a mold not designed for it: hence the metaphors of ghost or stream or steam or halo or genie. We want to say that the mind isn’t an object, thus indicating that facts about it are not divided up as material objects and their properties are. There is even some strain in the notion of a mental property (see Wittgenstein on “mental state”). Finally, it might be wondered whether vagueness puts a dent in the usual conception, because it undermines the picture of discrete bounded properties, and what it is to possess them. What kind of property is baldness? Frege didn’t think it was a property at all.[3]

But putting these possibly suggestive points aside, there is the deeper argument that there is just no good reason to suppose that reality must mirror the structure of human thinking. Even if we are stuck inside the subject-predicate cognitive structure, why should reality oblige us by conforming to it? Our concepts might not represent reality correctly, so why should our conceptual structurenecessarily represent it correctly? Our concepts occur not just in acts of predication but also exhibit other features: they compose to form complex concepts; they are subject to logical operations like conjunction, disjunction, and negation; they are subject to adverbial modification; they have intension and extension; and so on. Must the world answer to all these aspects? Must there be counterparts to them in reality? Our concepts serve our purposes, but those purposes don’t seem to include capturing the structure of reality in all its forms. So there seems room for a type of skepticism that questions whether predication can be read into reality, as it exists independently of us. It is hard to see what could quell such skepticism. And yet we have only the thinnest idea of what reality might be like if it doesn’t fit the object-property mold. I admit to having a split mind on the subject: the logician in me cleaves to the logical form supplied by the subject-predicate proposition, but the metaphysical realist in me acknowledges that reality is not compelled to mirror the human mind. Maybe reality is silently laughing at our subject-predicate obsession, our object-property hang-up, our particular-universal prejudice; but then doesn’t it have the property of laughing? Or is it that the word “property” is hopelessly undefined, a philosopher’s invention, stretched to breaking point beyond its tethering paradigms? And so we want to let out a philosophical scream–as Wittgenstein might put it. Back to the rough ground! In other words, we are caught in a classic philosophical dilemma: on the one hand, the world could not contain anything other than objects with properties; on the other hand, that looks like a prejudice born of familiarity and a lack of imagination.

How do we even possess these very abstract concepts of object and property, particular and universal, reality, fact, existence, being? They seem to reach far beyond anything we actually know about; and yet not quite so far as we seem able to contemplate when we think about absolutely everything. Our most general and capacious concept of reality seems hospitable even to worlds devoid of objects and properties–unless, of course, that is a metaphysical illusion.[4]


[1]At any rate, that’s a natural interpretation of his position: both the phenomenal world and the noumenal world consist of instantiated properties, the latter unknown by us. It would be possible, however, to hold that the noumenal world has another kind of reality, left unspecified.

[2]Time itself might be regarded as a counterexample to object-property ontology: are periods of time really objects that instantiate properties? If it rains over successive intervals, is this a case of temporal particulars (moments, eons) instantiating meteorological universals? Time seems like the wrong kind of thing to consist of discrete particulars. The subject-predicate form (“Today it’s raining”) here lacks ontological backing.

[3]Frege also didn’t think that existence is a property of objects, so an existential fact isn’t an object-property fact. Rather, it is a fact about concepts—a second-order fact. Thus not all facts consist in objects having properties—some consist in properties having properties. Are there possible worlds in which all facts consist in properties having properties instead of objects having properties?

[4]This is one of those vexing philosophical questions about which one seems able to slip in the blink of an eye from one position to another according to mood (and no doubt temperamental factors are involved). The romantic revels in the idea of a free and indeterminate world full of possibility, while the classicist prefers tried and true logical categories.


The Mystery of Motion



The Mystery of Motion



Consider a completely static universe—nothing moves in it. Within this universe there lies a sun and solar system just like ours except nothing is in motion, relatively or absolutely. Now ask yourself the question, “How would it move, if it were to move?” Can we infer from the properties it has how it would move? This seems difficult: the shape, color, chemical composition, volume, and mass of the objects don’t predict a unique course of movement. There is no entailment from these static properties to the dynamic properties of the objects.[1]That is, the dispositions to movement of our imagined solar system are not deducible from its other properties. They seem superadded not supervenient, certainly not reducible. So the basis of movement is not to be found in the intrinsic properties of objects. The question, then, is where it does come from—what is its origin? We might compare the question with a comparable question about consciousness: if we consider a universe just like ours physically, we find that consciousness is not entailed by the facts obtaining therein. God has more work to do in bringing consciousness into existence than just bringing physical organisms into existence. Similarly, God has more work to do in creating motion than just creating objects with static properties. The static world is like the zombie world—both are a step short of constituting motion or mind. A kind of dualism therefore seems indicated.

In Newton’s physics we find just such a dualism: what needs to be added is force. Gravitation causes planetary motion, and there exists a force of gravity. This force is proportional to mass, but it is not reducible to mass. There is a law linking mass and motion, but these are distinct attributes of objects. We only get motion when force is added to mass. Similarly, there may be laws linking brain states and consciousness, but there is no identity between the two. So Newton’s scheme is fundamentally dualist: force is to objects as the mind is to the body (under a dualist view of the latter). Force is an extra element or ingredient in the universe. Motion owes its existence to the existence of this force—itis the cause of motion.

But this motion-inducing force invites skepticism, often voiced. First, there is the question of its visibility: we don’t seem to see it—it is a theoretical postulate. Nor is it even likewhat is visible (as atoms are). It seems inherently unobservable (except by way of its effects). Second, we are told that it acts at a distance instantaneously; but that seems hard to credit, and it makes movement into an occult phenomenon. Third, how exactly is it related to other properties of objects? Are there possible worlds in which the same force operates but objects have very different intrinsic properties? Are there worlds in which feathers exert great gravitational force and suns very little? Fourth, and most concerning, the alleged force seems like an ad hocpostulation that simply summarizes observed motions: the force exists becauseof the observed motions—there is no more to its existence than the motions. There is certainly no evidence for its existence except the motions it allegedly produces. It looks suspiciously like a dormitive virtue brought in to explain soporific effects. Why do the planets move as they do? Because they are subject to a force that makes them move that way, i.e. they are disposed to move that way. The force doesn’t add anything; it just repeats what we already knew. It would be different if we could detect it independently of the motions it causes–but we can’t. How does the brain produce consciousness? By means of a force that works on (or in) the brain to generate conscious events—call it “psychical force”. That is hardly explanatory and smells like empty stipulation.

So should we get rid of this alleged force? General relativity is said to do just that: it replaces gravitational force with the structure of space. Massive bodies deform the geometry of space to cause the motions we observe. But how can spatial geometry cause motion? How can it trigger motion? Couldn’t there be a static universe consisting of curved space-time? Force at least offered to initiate motion—you just apply the force to an object. But how can curvy space initiate motion—where is the oomph? The theory tells us how an object will move through space when it moves, but it is silent on whythings move—what causes motion. The origin of motion is thus left obscure. It was just this problem that led to the doctrine of occasionalism: God is the origin of motion. Either God acts continuously to keep things moving or he starts the machine up and watches it play itself out. Proponents of occasionalism can’t see how motion comes about unless some sort of divine agency lies behind it—for what else could be the origin of motion? Similarly, God is supposed to create the mind and ensure its linkage to the body, since the body itself has no power to create minds. Thus motion argues the existence of God: no God, no motion; motion, therefore God. But theology aside, the doctrine is wheeled in to explain a physical fact, namely that things move. This seems unintelligible otherwise: for things need a reasonto move. Movement can’t be a brute fact.

Have we got over the problem of motion today? Does our current physics remove the puzzle? No, it ignores it. Sure, we have theories of motion that are predictive and mathematical—they characterize the laws that govern motion—but do they really explain why motion occurs? Do they explain what causes it? I don’t think they do–any more than current neuroscience explains what causes consciousness. The four forces recognized in contemporary physics are like Newton’s gravitational force in this regard: they are postulations made on the basis of nothing but observed motions. They are an I-know-not-what introduced to sum up observations. What isa force anyway? We might appeal to internal impressions of our acts of will, but that can hardly be an adequate basis for an ontology of physical forces. We are merely papering over our ignorance. Of course, positivistic philosophers and scientists might try to render the question meaningless, but I take it we need not travel down that dreary road again. There really is a genuine question about how motion comes to be—and we don’t seem to have much to say about it. It remains as mysterious as it ever was.

Three questions about motion may be distinguished, each calling for a theory, and each very difficult. First, what is the natureof motion—is it relative or absolute? Despite a preference for relative theories today, I don’t think this question has been resolved, or even properly posed—but I won’t pursue it now. Second, what are the lawsof motion? Here we have made impressive progress, beginning with Galileo and Newton, though quantum theory presents some substantial puzzles, especially in relation to microscopic motion. Third, what is the originof motion—what causes it? This is the question I am most concerned with here, and it is not answered by answers to the first two questions. It seems virtually invisible in today’s intellectual climate (as the problem of consciousness was until relatively recently). It is hard to get people to take the question seriously. There is a vague feeling that providing the laws of motion suffices to dispel all questions about motion: but that is surely wrong (as Newton himself fully recognized). How matter gives rise to motion is an unsolved mystery; as is the question of how it gives rise to just these motions and not those other ones. That is the point I tried to dramatize with the example of the static universe. Simply put, the question is why anything moves to start with. Was there motion before the big bang or did that event trigger motion? If so, how? Could there be an eternally static universe? Could matter, as we know it, stand stock-still? Could our universe ever cease to move? What would it take for motion to speed up? How exactly is the motion of an object related to its other properties? God was called “the prime mover”, but can he move? If not, how can he cause movement? I don’t think we have answers to these questions: we merely observe movements and then attempt to supply predictive laws governing them. But that project will only take you so far. We are very familiar with movement, both through our senses and in moving our own bodies; but what would we think if we had never experienced movement and then one day observed it to occur? Wouldn’t it strike us as miraculous? How could thisdo that? It would seem like an infusion from another realm not a predictable unfolding of what we already know. It would be like breathing life into a dead body. An infusion of electricity was necessary to do that in the case of Frankenstein’s monster, and a similar infusion would be needed to explain how immobile matter could become animated. The transition from immobility to movement through space is non-trivial, indeed remarkable. Earlier thinkers were impressed with this phenomenon, as contemporary thinkers appear not to be—I think we should return to earlier wonderment. How doesthe universe contrive to contain movement? We might label this the “motion-body problem”.[2]


Colin McGinn


[1]This basic point is found in Hume’s celebrated discussion of causation in An Enquiry Concerning Human Understanding. It is no accident that he uses the example of the motion of a billiard ball to illustrate his thesis that it is impossible to deduce causal powers from intrinsic properties of the cause. There is no reason, independently of “custom” (experience), to expect any specific motion upon impact given knowledge of the known properties of objects, or any motion at all.

[2]Similar themes have been voiced by Noam Chomsky, who observes that motion used to be regarded as a “hard problem”—and should still be so regarded.


Painting, Music, and Science



Painting, Music, and Science



You might embark on a self-improving trip to London and take in the Science Museum and the National Gallery. You would probably not experience any affinity between the two: the museum deals with science while the gallery exhibits art. There was no art in the science museum (except maybe some diagrams and illustrations) and there was no science in the art gallery (except maybe some portraits of scientists). But I think this would be a superficial reaction based on taxonomic conventions and preconceptions; actually there is much more science in an art gallery than one might naively suppose. Permit me then to make some hackneyed observations under this head, with no pretense at completeness or depth (this is art history 101).

The discovery of perspective was a scientific breakthrough and it changed the shape of artistic depiction. Artists like Leonardo and Michelangelo were interested in anatomy that required scientific enquiry, even dissection. The production and selection of paints, brushes, and canvas involved scientific expertise. Impressionism had roots in theories of visual perception. Cubism can be seen as a reflection of scientific views of matter. Surrealism drew on the (alleged) science of psychoanalysis. The shift from religious iconography, devotional and mythical, to realistic depictions of nature, descriptive and secular, was of a piece with a new scientific attitude to the world. Accuracy replaced pious evocation. Pictures of animals in books of natural history are not so far from pictures of people in natural settings. A still life is precisely a representation of a piece of nature without regard to any spiritual meaning it might have. So when you gaze at a painting in an art gallery you are seeing it through prisms of science, because science is present in the worldview and practice of the painter—it is part of his or her culture. The painter was not much of a scientist when decorating churches with religious images, as the writer of ancient religious texts was not; but later painters adopted the stance of science in their work simply because they lived in a world permeated by science. The physical world is a subject of science and human visual perception is also a subject of scientific study. An artist is not cut off from these influences.

But I want to say something stronger—that painting of the realistic sort isa science.[1]The painter of nature is a scientist. This is because such painting requires careful attention to nature and a systematic attempt to depict it accurately. There are general principles at work here concerning background and foreground, light and shade, size and color constancy, the exact structure of a tree or building or face. The scientific illustrator has to have the same skills and aims, and we would not hesitate in classifying him as a scientist (scientists often illustrate their own books); the painter is not engaged on some completely different enterprise, though obviously there are differences of intention and execution. There is no sharp line at which a drawing stops being scientific and becomes artistic. The two are indissolubly connected. The use of scientific instruments in art confirms this point.[2]Depicting nature in oils is not so different from describing it in words—both are attempts at getting nature right. The artist is a student of the natural world who adopts the medium of painting to capture his object of interest. This natural world can include the human social world. In a broad sense the realistic painter is an anatomist—of the human body, to be sure, but also of the non-human environment. Truth and verisimilitude are the aim. Recurring patterns are recognized and recorded. Objective reality is respected and revered. The attitude is essentially scientific—not religious or anthropocentric or sophistical. The aim is to produce likeness—just as the scientist wants to describe reality as it is. Painting is about the eye and what it reveals, but science too is based on observation and what it tells us of reality. Both science and art are observational, grounded in the senses, not on a supposed source of divine revelation or the texts of an ancient authority. They attempt to capture nature as it presents itself. The painter is thus a physicist, botanist, and zoologist. She is also an empiricist, relying on her own unfiltered experience to construct accurate representations of the world (painting is not an a prioriscience). This may be pictorial physics (botany, zoology) not discursive physics, but it is still the study of the physical world. We might call it phenomenologicalphysics to register its dependence on the conscious perception of reality, as opposed to abstract theoretical cognitive physics. But phenomenology is a science too. I would even be willing to say that it is an experimental science, given that the painter tries out different methods of obtaining an accurate representation—and there is scientific progress in the art of painting. The scientific and artistic renaissances were aligned ventures. The history of art and the history of science are not insulated from each other.

The same can be said about other visual arts: photography, film, and architecture. These all contain a strong scientific component and often owe their origin to a scientific invention. Being an art form in no way precludes also being a science. Aesthetic value is not incompatible with scientific precision. The raw materials of these art forms are different, but they all involve elements of science: how paint adheres to canvas, the action of photographic plates, the technology of the moving image, the physical constraints of architectural construction. There is a scientific infrastructure. And the aims of these art forms are not so removed from scientific aims as institutional conventions might suggest: all are concerned with truth, accuracy, verisimilitude, understanding, and generality. Not in the same way, to be sure, and not exclusively (there is also the matter of beauty): but it is not that science and art are entirely separate domains of interest with no overlap or commonality.

What about music? Am I about to claim that music scientifically depicts observable reality too? And isn’t that very hard to believe? No, I am not about to claim that; but I am going to claim that it is based on another type of science, viz. mathematics. In fact, my claim, baldly stated, is that the musician (composer, performer) isa mathematician. Again, I will not go into elaborate detail about the grounds for saying this, but merely recite some fundamental facts about music.[3]Musical theory is a technical systematic field based around the notion of scales. A scale is a structure of pitch intervals divided into whole tones and semitones (though there is also atonal and microtonal music). This is defined mathematically with numbers assigned to the constituents of the structure (also letter names). One of the simplest scales is the pentatonic scale, which includes a subset of the notes of the major scale. Notes are grouped into octaves according to the frequency of the underlying sound wave. Essentially, musical notes are digitized products of a pitch continuum. The pitch relations are mathematically defined. For example, the so-called blue note is a flatted third or fifth added to the pentatonic scale—a lowered semitone. All music is based around these mathematical relations (hence Pythagoras’s interest in music). Different types of music use different scales, with Western music focusing on the major and minor scales (Eastern music uses other scales). So when you hear a piece of music you are hearing pitch relations that conform to a mathematical structure. If they didn’t, the music would make no sense. Music is made of what music theorists call “intervallic structure”.[4]You hear instances of this structure asmusic. So the conceptual foundation of music is the science of mathematics, which is a formal not an empirical science. A composer is in effect a mathematician of sound. I don’t think this is a controversial claim, but it implies that music is a science too—despite also being an art. This is as true for raucous rock n’ roll as for a Bach cantata. So if you visited the Albert Hall on your trip to London, you would have been immersed in science there too. You can’t get way from it.

In addition there is the technology and science that goes into constructing musical instruments, as well as recording studios, etc. All instruments have to be designed by scientific principles in order to produce sounds and to be durable. A guitar is as much a piece of technology as a microscope. Even the human voice is a technological contraption. A singer has to operate this instrument with scientific precision, and it can take years to get the right sound out of it. Music is not cut off from the world of physics and must respect its laws. A musical performance is an amalgam of mathematics and physics, as channeled through the human ear. A composer has to organize intervallic structure and physical instrumentation to produce a musical work of art—so he or she is doing the work of a mathematician and a physicist. Again, this is phenomenological mathematics and physics, not to be confused with the discursive studies pursued in obtaining a university degree in those subjects. It involves mathematical and physical know-how (which animals don’t have). This intuitive knowledge can be made explicit in music theory and physical theory, but it is still mathematical and physical in nature prior to such articulation. Music theory makes explicit what the ear already knows.

I can now return to a topic ignored in my discussion of pictorial art: the nature of abstract art. What are we to say of those paintings that spurn all attempts to model the natural world and revel purely in abstract forms? Well, there are different types of abstract art, but one form can be regarded as analogous to music—it is the study of mathematical structure as such. It uses the visual analogue of intervallic structure—the placing of lines at certain distances from each other (as pitch relations can also be spatially represented). So abstract art can incorporate science rather as music does—by playing with mathematical form. This is a kind of a priorivisual art, which would be beloved by rationalists (the artistic empiricist likes her art to faithfully copy visual impressions). Thus we have a prioriand a posterioriart: music and abstract art are the former, realistic naturalism the latter. In both cases the artist is beholden to science and might as well be declared a scientist herself (as well as an artist). The traditional classifications are arbitrary and misleading, since art is inextricably bound up with science. What the artist needs is knowledge, and that can include what we now call “science”. To put it differently, physics is more than what physicists study and mathematics is more than what mathematicians study (and the same is true for botany and zoology): these subjects are also studied by painters and musicians each in their characteristic way. The painter studies the physical world as it is seenand the musician studies the mathematical world as it is heard—phenomenological science in both cases. What we call “artists” and “scientists” are really close colleagues. Art galleries are also science museums. Just as novelists are scientists au fond(keen observers of nature), so too are painters and musicians. Granted they have other talents too, but let us not place them in a ghetto reserved for the scientifically illiterate or uninterested. Art is one form the scientific spirit can take.[5]


Colin McGinn

[1]This essay twins with my “Fiction, Fact, and Science”, which makes a similar claim about literature.

[2]The Hockney-Falco thesis is interesting in this connection: this is the claim that painterly realism was aided and abetted by the use of optical instruments such as the camera lucidaand concave mirrors, thus incorporating the science of optics into artistic practice. Fittingly, Hockney is a painter and Falco is a physicist.

[3]I am not an expert in music theory; what I offer here is just what I picked up when learning to play guitar. Still, it should suffice for present purposes.

[4]There is also rhythm–a temporal mathematical structure. We hear this rhythmic structure as much as we hear pitch structure. And notice how important recurring patterns are in music, rather like recurring patterns in nature. The same “laws” crop up in different particular sounds and we recognize their recurrence.

[5]You might object that I am using the words “science” or “scientific” very promiscuously. That is true and it is done with malice aforethought. I also count philosophy as a science, as well as psychology, economics, linguistics, mathematics, etc. I don’t think we should restrict the word to the so-called physical sciences. The honorific connotations of “science” should be spread more widely. And don’t ask me to define “science” beyond saying it is secular evidence-based logical thought (roughly). What matters is that particular activities should exhibit a commitment to scientific principles and values.