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.


Fiction, Fact, and Science


Fiction, Fact, and Science



A library divides its books into two sections: fiction and non-fiction. The assumption is that fiction is concerned with fictions while non-fiction is concerned with facts. Science books will appear in the non-fiction section, being concerned with facts. Novels will appear in the fiction section, being concerned with fictions. Works of fiction are fictitious—they consist of falsehoods; works of science are “factitious”—they deal in truths. This is a neat arrangement and it facilitates the finding of books. But it is seriously misleading, if not downright erroneous. The obvious point is that so-called works of fiction contain a lot of truth, especially if they are good.[1]Not everything said or implied by a novel is fictitious, i.e. untrue; much may be profoundly true. Standard dictionary definitions make room for this point: thus the OEDdefines “fiction” as “prose literature, especially novels, describing imaginary events and people”. This is compatible with accepting that novels alsoconvey important truths—they are only partlyfictitious. Indeed, they convey truths byconstructing fictions; and that, arguably, is their main point. About what do they convey truths? About, as we like to say, human nature: human emotion, action, morality, mortality, stupidity, virtue, etc. When you read a novel you learn about human behavior, human motivation, human experience, the human heart. If a novel were completely false to human nature, it would not interest us. So we read fiction (in part) to learn facts: much of fiction is non-fiction. It would not be wrong to place novels in the non-fiction section away from the astrology books or alternative medicine tracts or religious tomes.

Can we define fiction in terms of imaginary events and people? A novel presents an imaginary world of people and things undergoing various changes, while a work of non-fiction like a science book deals only in real things. But this would be wrong, because the imagination does enter into the content of works of non-fiction. Consider the thought-experiment, that staple of philosophy and science: this is an imaginary scenario designed to convey truths (e.g. Einstein riding on a beam of light, a Gettier case). We engage in counterfactual suppositions and ask what to say about them. We thus traffic in fictions. They are not put forward as descriptions of reality, but they help us know reality better; no one is misled or complains of falsehood masquerading as truth. In this they resemble the sentences of a novel. So we could say that works of science can contain fictions as well as facts—just like novels. Both contain both. The imagination is employed in both contexts.[2]And it serves an instrumental purpose: to convey truths. Indeed, I think it is illuminating to say that a novel isa thought-experiment: it constructs an imaginary scenario and spells out its consequences as they are manifested over time. Suppose persons A, Band Cto be in situation S; then such and such would or might ensue. As a result of this exercise of imagination we gain a better insight into human nature (I’m not saying this is allwe get from reading a novel). So science and literature can be said to employ thought-experiments, which is to say imagination. If so, we cannot distinguish between the two by saying that fiction uses imagination while non-fiction (e.g. science) does not. Nor can we distinguish them by saying that fiction is not concerned with truth while non-fiction is, since both are.

My thesis is that fiction is a kind of science in which the thought-experiment plays a particularly prominent role. The novelist is a type of scientist. Recent trends in literary studies have played with the idea that science might be a type of fiction; I am suggesting that fiction is a type of science. What is it a science of? Of human nature obviously: it is a concerted effort to arrive at general truths of human nature, based upon observation and analysis. It looks for causes and laws, hidden mechanisms, deep truths. It is a branch of human psychology and sociology and anthropology—the branch concerned with specific people in specific situations. So novels belong in the science section of the library, the section containing physics, chemistry, biology, psychology, etc. They are works of scientific exploration directed towards describing and understanding human beings in situ. They are not pseudo science or supernaturalism or myth or fairy tale (though those forms can have scientific aims too): they are naturalistic studies of a certain natural phenomenon—the human animal in its natural niche (society). As such they tend to be concerned with particular human types and how these types interact. The form of the novel—a lengthy thought-experiment—is designed to elucidate human types and their characteristic interactions. And when a novel succeeds it enlightens us about matters of fact. Thus there is no deep reason to separate works of fiction and works of fact—literature from science. All are in the same basic business.

Let me cite three classic authors to illustrate this position: Jane Austen, William Thackeray, and George Eliot. All wrote at the beginning of the nineteenth century when the “realistic novel” took shape, and all lived at a time of critical scientific importance. I am talking particularly about Charles Darwin, but there were other scientific developments that coincided with this period in English letters. This was the age of naturalism. I won’t discuss these authors in detail but just make some general observations. Jane Austen writes about romantic passion and its relation to marriage during a particular period of British history; and she explores the many types of personality that populate this fraught socioeconomic landscape. She is particularly concerned with human error about the feelings of other people, but also with the fleeting period during which “attachments” may form and marriage becomes possible and necessary (notably for women). She minutely examines the interplay between money and marriage, with special attention to manners and class. Thackeray is also much concerned with human types, but dwells more on human weaknesses of various kinds, and the unlimited possibilities of human suffering. His landscape (“Vanity Fair”) captures the injustice and randomness of human happiness and misery, especially in the matter of inheritance and money. He casts a beady eye on human vanity and social striving, sharply distinguishing the types with which he is concerned. He is a naturalist of the human condition as it then obtained, often tracing adult behavior back to childhood experience. Heroism is sacrificed to unblinking accuracy in his narrative. His world is ruthlessly Darwinian (in the vulgar sense): it is all about survival in a hostile environment. George Eliot is overtly interested in science and makes frequent mention of it (microscopes and telescopes); she refers to John Locke, one of the early scientists of human nature. It is known that she read and was influenced by Darwin; his mark is clearly present in her pages. She adopts a scientist’s perspective on her subjects, again concerned with human types and their characteristic behavior. She is analytical and objective, quite unsentimental. The reader feels she is doing for human society what Darwin did for the animal kingdom. The naturalistic scientific attitude pervades her work.

The nineteenth-century novel thus enters a scientific phase similar to that of the natural sciences, particularly biology: close impartial observation, shunning of the supernatural, descriptive precision. The novel is simply the linguistic form that the scientific impulse took at that time (psychology and sociology as we now know them did not exist then). So these novels can be regarded as the works of naturalists of human nature—hence as scientific studies. They are not sermons or recitations of divine providence or the repetition of traditional pieties; they come from keen observation of the natural world. One thing that stands out in all three novelists is the dialogue: it is scrupulously naturalistic, not biblical or Homeric or Shakespearean. People are described as speaking exactly as they actually do speak, as if recorded by the author—which is a source of verisimilitude as well as amusement. Here we have the field linguist setting down his data without preconception or prejudice. This is pure anthropology. There is thus no deep discontinuity between what the novelist does and what a scientist might do: both are concerned with the truth, and empirical observation is the preferred method of arriving at it (not consulting tradition and ancient texts).

I think what I am saying would have been found very reasonable at the time these novels were written, but since then lines of demarcation have been more starkly drawn. The concept of science has hardened and rigidified–now conjuring up images of labs and particle accelerators, with heavy infusions of mathematics. Then too, we have the institutional divisions of a modern university (with its library arrangements). But that was not the conception of earlier scientists, for whom the roving naturalist was the paradigm (hence “natural philosopher”). The naturalistic novelist was simply taking this one stage further: he or she is a scientist of human society. The fictional form seemed the obvious way to express the insights gleaned. Scientists and philosophers had adopted the dialogue form to add drama to disquisition (Plato, Galileo), so it was natural to use drama as a way to express insight into human affairs. There is just no sharp line here. Literature and science are not opposed to each other; both have the same ultimate goal. The bifurcation into fiction and non-fiction is therefore superficial and spurious. This is why Freud found it plausible to suggest that works of fiction predate some of his ideas—precisely because they contain insights into human psychology. He was expressing in discursive theoretical form what they expressed in literary dramatic form: the same truths are being communicated.[3]So if Freud was a scientist of the human psyche, then so were the novelists who preceded him.

Suppose that what you took to be fiction turned out to be fact: the novel you just read was actually reporting real events happening to real people. And suppose it contained some startling insights into human psychology, perhaps of a general nature. The same insights might be discovered by a psychologist who chooses to express them in non-fiction form. Wouldn’t that be enough to warrant describing the novel as a scientific work? But any novel could turn out to be factually true—that is always an epistemic possibility. So, if the novel contains information that would count as scientific outside of the novel form, wouldn’t that make it count as scientific itself? The fact that a standard novel uses a thought-experiment to establish general factual truths should not detract from its status as a scientific work—any more than thought-experiments in physics render physics non-scientific. I would say that the three novelists I mentioned were not only scientists but great scientists—right up there with Darwin and company. They delved deep into the human soul.[4]



[1]Of course, if novels describe possible worlds, and possible worlds are real, then novels describe reality, so that everything they say is literally true of somepossible world. But I will put this on one side and consider only what they say about the actual world.

[2]The imagination is also involved in the creation of scientific theories, as has often been noted. Science also employs idealizations and “useful fictions”. It is not just the bare recording of fact.

[3]I don’t mean to suggest that I think Freud’s theories are true (on the contrary), but it was not wrong of him to find in literature a fund of psychological knowledge. The idea that academic psychology will never overtake literature as a source of psychological insight is also not wide of the mark, suggesting that literature constitutes a superiortype of science.

[4]Part of the point in insisting on the scientific status of the novel is the honorific connotations of the word “science”—we shouldn’t let them accrue only to certain speciesof scientist.


Against Family Resemblance


Against Family Resemblance



After the well-known section on games in Philosophical Investigations(section 66), Wittgenstein writes: “I can think of no better expression to characterize these similarities than ‘family resemblances’; for the various resemblances between members of a family: build, features, color of eyes, gait, temperament, etc. etc. overlap and criss-cross in the same way. And I shall say: ‘games’ form a family.”[1](67) He then goes on to suggest that the kinds of numbers “form a family in the same way”. He gives no further examples, though he employs the concept to characterize language: “I am saying that these phenomena [linguistic phenomena] have no one thing in common which makes us use the same word for all, but that they are relatedto one another in many different ways.” (65) There is not much to go on here, given how important the notion of family resemblance is to Wittgenstein’s later philosophy, but I think we have enough to raise some serious objections to what he says. I am going to argue that the concepts in question are not family resemblance concepts, and indeed that there are not and cannot be any such concepts.  The whole idea is a mistake—and not for any particularly profound reasons. Wittgenstein’s laconic remarks are full of errors, confusions, and non-sequiturs.

The first point I want to make is that the concept of a family resemblance concept is not itself a family resemblance concept. Consider the class of family resemblance concepts—say, game, number, languageand art(not mentioned by Wittgenstein): do they have any common feature? Yes, they are all such as not to be defined by a common feature but by a series of overlapping similarities—that is the common feature they all share. Wittgenstein has given us a general definition of the term “family resemblance concept” such that anything denoted by it satisfies that definition; it is not just that the concepts are similar in certain ways, as games are said to be. So we know there is at least one non-family resemblance concept, viz. family resemblance concept. This is a bit ironic and certainly not noted by Wittgenstein: it should make us wonder about the generality of the idea. It renders contradictory the claim (not made by Wittgenstein) that all concepts are family resemblance concepts, since thatconcept isn’t a family resemblance concept. It also raises the question of how widespread family resemblance is according to Wittgenstein, and why it has the extension it does. Does he think it is limited to the examples he mentions? And what is it about these examples that requires the use of family resemblance concepts instead of common feature concepts? It would be odd if such a heterogeneous group were the only instances of the phenomenon, with all other concepts proudly possessing uniting common features. The notion doesn’t seem to have been systematically thought out and looks suspiciously ad hoc.

Now consider what is meant by “family resemblance” (elsewhere Wittgenstein speaks of “family likeness” and we could also say “family similarity”). This is not the same notion as that of belonging to the same family: that is a matter of parentage and genetic transmission, and is presumably not counted by Wittgenstein as a family resemblance concept. He is talking about various observable traits typically shared by members of the same biological family, as his list suggests. He doesn’t confine the notion to visual appearances, since he includes temperament, and he could have included aptitudes, intelligence, religious beliefs, etc. There are a great many respects of similarity between human beings. Nor does the notion coincide with membership in a biological family: some members of a family are not similar to any other members, and some people from outside the family look just like people in it. The class of people who are notably similar to members of a given family is distinct from the class of people actually making up the family. These are really completely different concepts. In fact, Wittgenstein need not have invoked familyresemblance at all; he could have just spoken about similarity in general. Take three cars, a,b, and c, where aand bhave the same color but are not the same model, while band care the same model but not the same color. Car a is similar to car bin respect of color but not similar to car cin that respect, whileband care similar in respect of model but not color.[2]Thus we see the non-transitivity of similarity: ais similar to band bis similar to c, but ais not similar to c. The same could be true of individuals exhibiting family resemblance. So Wittgenstein is really drawing attention to the way the concept of similarity works—not a very startling insight. The question is whether similarity relations can ground a unified concept.

Notice that there is no unified (non-disjunctive) concept that corresponds to the list Wittgenstein offers. What concept do we have that expresses likeness of eyes, mouth, gait, and temperament? We might try to manufacture a concept, say Smith-ish, to characterize a certain family’s appearance, where not all members of the Smith family are Smith-ish and some non-members are Smith-ish: but this a pretty feeble concept with little internal unity. And the reason for that is that mere similarity in a respect is no basis for a concept, since everythingis similar to a given thing in somerespect. The class is simply too heterogeneous to be worth picking out. This is not so for the concept of a family, which is far more constrained; and one can’t help suspecting that Wittgenstein’s choice of familysimilarity illicitly trades on this other source of conceptual unity. For familyis a unified (common feature) concept while family resemblanceis not—it could include members of (say) my family as well as assorted people distributed across the globe who look or behave like me in some respect or other. To look like someone that looks like Winston Churchill is no basis for a usable concept (it includes certain breeds of dog or even clouds). That is why there simply is no concept that corresponds to Wittgenstein’s list. It amounts to an uninteresting disjunction: xlooks like a member of family Fif and only if xeither has the eyes of For the nose of For the mouth or the gait or the temperament or the size or the color or the religious beliefs of F, etc.

Then what are we to say about Wittgenstein’s alleged examples—aren’t theyexisting unified concepts that are characterized merely by non-transitive similarity? The question is whether games are linked by nothing butfamily resemblance: is there really nothing they have in common? Two points may be made. First, Bernard Suits’ analysis of the concept of a game refutes this contention: a game is a rule-governed activity in which the player voluntarily chooses an inefficient means to achieve the goal of the game. I won’t go into this here; it has been amply discussed elsewhere.[3]What I will say is that the existence of such an analysis is entirely predictable, given the unity of the concept of a game and the complete lack of unity exhibited by the pattern of similarities and dissimilarities to which Wittgenstein draws attention. Second, why can’t we say that what is in common to all games is that they are all games? That is, we treat the concept of a game as primitive and unanalyzable (we might add that all games are played). Consider the concept of a line: there are all sorts of lines—long, short, squiggly, curved, straight, open, closed, etc.—and it is hard to find one such feature that all lines share. So is the concept of a line a family resemblance concept? Why not say—what seems obvious—that the concept of a line is primitive and cannot be explained in other terms? Wittgenstein appears to be presupposing that if a concept isn’t analyzable it must be a family resemblance concept—he conveniently forgets about the possibility that it is indefinable. Compare color and shape concepts: here too we have a great variety of things that fall under these concepts and no possibility of unifying them by citing a specific color or shape. So what? Why not accept that the concepts colorand shapehave no non-circular definition, yet apply to very heterogeneous extensions? The same goes for animalor particle: these come in great variety too and it is hard to define the concepts in non-circular fashion—but why leap to the idea of family resemblance instead of accepting indefinability? And notice that Wittgenstein never cites such examples, presumably because it is obvious that the indefinability response is plausible. So we are certainly not compelled to accept the family resemblance theory—even if it were coherent—in order to handle the case of games. In fact, the concept of a game has sources of unity quite other than that (dubiously) provided by family resemblance.

The case of numbers is even more glaring, and it seems distinctly odd for Wittgenstein to choose this example to illustrate his thesis. What do cardinal numbers, rational numbers, and real numbers have in common? Well, we could just say they are all numbersand admit that the concept cannot be defined; or we could note that all numbers are subject to mathematical operations such as addition, subtraction, and division–or that they come in different sizes, belong in number series, and can be used for measuring and counting. There is actually a lotthey have in common. More adventurously, we might also add that they all admit of set-theoretic construction. You might as well say that organisms have nothing in common or chemical compounds or trees or houses. True, there is a lot of variety in those classes, but that doesn’t preclude a common feature—either expressed by the concept in question or by some analysis of it. Wittgenstein never makes a convincing case for the thesis that any of these concepts mustbe treated as family resemblance concepts. Nor can such a treatment confer the kind of unity possessed by these concepts. How, say, can Wittgenstein explain the fact that golf is a game but hitting stones with sticks to clear a patch of land is not? There is an obvious similarity between these activities, yet one is clearly a game and the other is definitely not.[4]Similarity in some respect is a hopelessly weak relation to ground a concept, because it is so cheaply obtained. A different principle of grouping is needed.

What about language? There are certainly different dimensions of similarity among words: words can sound alike but not mean alike and vice versa, for example. But is there really nothing they have in common? Don’t they all contribute to forming sentences, and don’t all sentences have meaning and grammar? By all means let’s recognize the variety of linguistic forms, but why deny that anything can be said more generally? Aren’t all words and sentences usable in acts of communication? Isn’t human language a species-specific biologically given trait with infinite potential? There is plenty we can say generally about language. True, it is a mistake to suppose that every sentence expresses a proposition, as the Tractatusclaimed, but there is no need to go to the other extreme and declare that there is no common feature at all to language. Moreover, many things that don’t belong to language are similar to things that do, so similarity alone cannot be grounds for inclusion under the concept. The screeching of tires could sound like a cry for help, but it isn’t a part of language. The humming of a bee’s wings is not part of its language, though its dances are; and our dances are similar to theirs but not part of our language. Mere similarity to a paradigm in some respect is nothing to the point.[5]

In sum: there are no good examples of family resemblance concepts; the notion is incoherent; and the concept itself is not an instance of itself.



[1]Why he puts the word “games” in inverted commas here I don’t know, since he clearly means to be talking about games not the word “games”: but let that pass.

[2]He might also have spoken of racial resemblance where much the same pattern of similarities and differences obtains.

[3]See Bernard Suits, The Grasshopper: Games, Life and Utopia(1978). I discuss the matter in Truth By Analysis: Games, Names, and Philosophy(2012), chapter 2.

[4]Compare Suits’ remark: “For if family resemblance were the reason they are nearly all called games, then it would be puzzling, I submit, why a cop chasing a robber is notcalled a game.” (173)

[5]It is notable that when Wittgenstein is trying to explain his notion of a family resemblance concept he falls back on metaphors in order to capture conceptual unity, specifically the metaphor of a thread made up of overlapping fibers. But this does nothing to render his theory intelligible, since it is just a metaphor.


Modal Objectivism




Modal Objectivism



It is now almost fifty years since Kripke made his celebrated distinction between epistemic and metaphysical necessity.[1]He pointed out that not all necessary truths are known a priori: for example, it is not a priorithat this table is made of wood, but it is a necessary truth—this very table could not have been made of plastic. Similarly for water and H2O, heat and molecular motion, a person and his origin, an animal and its species, etc. Since these necessities are not a priorithey are not analytic, i.e. a consequence of the concepts involved. Thus it follows that they do not depend on our concepts: they do not arise from the content of our thoughts or the meaning of our words. To that extent they are not mind-dependent. It would be tempting to conclude that Kripke established the objectivity of necessary truths: he established that there are necessary facts obtaining independently of minds. This table would necessarily be made of wood even in the absence of human beings and their minds (or any other form of intelligence). Kripke certainly talks this way, without making explicit that he is affirming modal objectivity. If necessity doesn’t depend on our concepts, but on “the world”, doesn’t it follow that it obtains independently of minds? And isn’t it intuitively obvious that water is necessarily H2O whether or not anyone refers to or thinks about water?Likewise, isn’t it obvious that water is only contingently found on earth whether or not anyone talks about water? Aren’t these objective modal facts once we distinguish them from analytic and a prioritruths? So doesn’t Kripke’s distinction establish modal objectivity? I certainly have assumed as much for the last fifty years.

But the matter is not so obvious on reflection: for there are other ways to formulate modal subjectivism than by equating necessity with analytic or a prioritruth. So the correctness of Kripke’s distinction does not entailmodal objectivism. For instance, one might claim that modality consists in dispositions to produce impressions of modality—as color consists in dispositions to produce impressions of color.[2]Thus for this table to be necessarily made of wood is for it to be disposed to cause in subjects the impression that it is necessarily made of wood. If that were so, the necessity would not be mind-independent; in the absence of minds there would be no such modal fact (compare colors). In other words, if modal properties were secondary qualities they would not be objective. And to be a secondary quality is not to be a priorior analytic: it is not a priorior analytic that this table is brown, but being brown is mind-dependent (assuming the dispositional analysis of color). Thus modal subjectivism is logically compatible with accepting Kripke’s distinction. For all Kripke has said, modality is entirely in the mind not in the world, de mentenot de re. Similarly, someone who believes that necessity arises from our practices of individuation will also reject strong modal objectivism, since necessity will then depend on the human agent. Suppose it is claimed that we individuate the table by means of its composition not by its location (since it moves around) and that is why we rate its composition as necessary. Such a theorist would be committed to a mind-dependent view of so-called metaphysical necessity. The impression of necessity is a function of our practice of identifying and re-identifying objects; there is no more to it than those practices. Or again, suppose the theorist is an expressivist in a variety of domains (ethics, aesthetics, probability) and wishes to apply this doctrine to modality, holding that “This table is necessarily made of wood” merely expresses an attitude about the table not a fact about it. It is a fact that the table is made of wood but not a fact that it is necessarilymade of wood—that is no more an objective fact than the “fact” that torture is wrong. Both are expressions of human sensibility. Such a view implies that modality is not an objective matter—a matter of facts obtaining independently of human sensibility. But it is not the doctrine that all necessity is a priori. Modal subjectivism can take other forms.

Now it is not that I take any of these views seriously: I am a convinced objectivist about the metaphysics of metaphysical necessity. I am merely indicating a gap in the argument for modal objectivism. The question is how to close this gap, given that Kripke’s distinction isn’t sufficient. And here the matter grows murkier—more profound, if you will. For it is not clear how to argue for the objectivist position: we have here a clash of basic intuitions. The modal subjectivist can’t see how objective reality could contain modal ingredients to be set beside tables, piece of wood, particle and planets–as she can’t see how values can exist objectively alongside facts. The modal objectivist prefers a more expansive view of reality and recoils at the idea of consigning necessity to the subjective world. How can we decide between these views? It is no use appealing to intuitions about what reality would contain in the absence of minds, because those intuitions are likely to conflict according to philosophical predilection. However, there is a type of argument that can at least focus the issue—and which to my mind settles it in favor of objectivism. This is what we can call an inversionargument, familiar from discussions of color. What if Martians see as green what we see as red—would they be wrong? Intuitively the answer is no: they would simply see the same objects differently. Objects have color only relative to a chosen class of perceivers, not in themselves. By contrast, if Martians see as circular what we see as rectangular, one of us would have to be wrong—because shape is objective. Where does modality fall? What if Martians were under the impression that the table is contingently made of wood and necessarily located in a certain place—would that just be a matter of their subjective response, true relative to them? I think not: they would be wrong so to suppose. Clearlylocation is not an essential property of the object, and clearlycomposition is. Likewise, it is not a relative matter whether water is necessarily H2O and contingently in my cup—anyone who thought otherwise would be wrong. The same point can be made about the expressivist and the enthusiast of individuation: inversion does not preserve truth. Modality does not track response; it can falsify response. Modal truth is not response-dependent. So now we have an argument in favor of modal objectivism and can relax into the mode of speech Kripke found so natural, in which we speak of necessity as de re, in the world, an aspect of objective reality. The table in itself is necessarily made of wood no matter what anyone thinks, and water is necessarily H2O irrespective of anyone’s impression. Even if no intelligent beings had ever existed de renecessities would still exist, and contingencies too. Not only is necessity independent of concepts; it is independent of anything mental. Not only are there metaphysical necessities; there are objective metaphysical necessities.[3]


[1]Naming and Necessity(1972); originally given as lectures in 1970.

[2]Hume provides the locus classicusof this type of view: causal necessity consists of nothing more than our habit of moving mentally from cause to effect when exposed to constant conjunctions—we project causal necessity onto the world. At least that was the traditional interpretation of Hume, which I reject (along with many Hume scholars): the correct view is that he believed in objective causal necessity but thought we could have no adequate idea of it, though we do have a kind of surrogate idea deriving from our inner inclinations. At any rate, the traditional interpretation gives a model for the type of subjectivism I am interested in describing (but not endorsing).

[3]It is completely unclear to me from Kripke’s text whether he subscribes to modal objectivism as a piece of metaphysics, since he says nothing explicitly on the question; but his general style of talking indicates that he would accept it.


Generative Economics

Darwin’s theory of evolution includes two generative components: mutation and natural selection. Mutation generates genetic variants and hence phenotypes; natural selection operates on these to produce differential survival. Neither of these generative processes involves intention or intelligence. Thus we have biological novelty without intentional intelligent design. Both processes are blind and driven by non-mental causes. We have creativity without a creator. But Darwin also recognized what he calls artificial selection, as with the selective breeding of dogs (or horses and flowers). Here human beings intentionally direct the course of evolution according to their own preferences, producing dog breeds that would not arise by natural selection. This is not selection by nature but selection by human design and desire. Of course, the process of generation is still natural not artificial: dog breeders rely on the genes to generate dog variants. They don’t make poodles from scratch; they just interbreed dogs and let the genes do their work. So here we have a case of natural generation and artificial selection to be added to the far more common case of natural generation and natural selection. Dog breeders don’t even know how to generate dog variants artificially; they depend upon natural reproduction.

In principle there could be artificial generation combined with natural selection: a type of intelligence creates an organism and then turns it loose in the world to the tender mercies of nature. You could genetically engineer organisms and then let nature select the good from the bad. In effect that is what happens with many human artifacts: they are intelligently created but left for nature mindlessly to destroy or preserve (as with architectural ruins and plastic bags). What about artificial design combined with artificial selection? Can there be intelligently created entities that are then intelligently selected? Of course, there can: machines created by humans and selected by humans to be used as they see fit. Motorcars are propagated by these two modes of generation: first they are designed and manufactured by the use of intelligence; then they are bought and sold in the marketplace by a process of intelligent selection, intentionally and consciously. So there are four logical possibilities in all: natural generation and natural selection, natural generation and artificial selection, artificial generation and natural selection, and artificial generation and artificial selection. Entities can come into existence and reproduce (or be reproduced) by any of these four methods.

There is something strange in Darwin’s terminology, because so-called artificial selection is itself a natural process. The mind is natural and it is what directs selective breeding; there is nothing super-natural going on here.[1]Bees select flowers and hence direct the course of flower evolution: this is not “artificial”. When humans selectively breed animals for their own purposes this is an aspect of their species-specific nature. It would be better to speak of intentional intelligent selection versus selection that is neither. For intelligence is part of nature too. Still, we can keep the terminology for convenience. The question I am interested in is the nature of economic activity; and what I want to maintain is that economic activity is continuous with biology. It is just another form of biological generation. Now it is true that (so far as I know) other animals don’t engage in economic activity, though it would serve my purpose if they did; but that doesn’t prevent us from imagining such activity in animals. So suppose we encountered a species of bird that manufactures nests that it exchanges with other birds for food. Instead of just building a nest for its own use, it builds nests “for sale”. This has become part of its genetic make-up, as much as nest-building itself. We can think of it as instinctual and automatic, like birdsong, and not as reflective and flexible: birds that exchanged nests for food in the past (as a result of some mutation) did better than birds that kept their nests to themselves. Thus a primitive bird economy develops. In such a case we would say that the entire process is part of the bird’s biological endowment. The “buyer” birds would select nests according to their own criteria and a form of competition might develop, which would lead to a selection process. In just such a way human commerce might have originated: humans capable of exchange do better than humans incapable of it. This would also be as biological as digestion and sexual reproduction, whatever the later elaborations (banks, money). It is a form of social behavior rooted in biological imperatives.

So there are two principles of generation at work here: generating the nests and their being selected. Both are “artificial” in Darwin’s strained sense, since they involved goal-directed action. The bird makes the nest not its genes and other birds do the selecting not brute nature. But this doesn’t exclude the phenomenon from the realm of biology. Or again, consider those ants that enslave other ant populations: these “brood parasites” seize the eggs of other ants and bring them back to their own nest where they carry out the work of their “slave-owners”.  Again, I don’t know of any documented cases of ants that then trade their slaves with other ant slave-owners, but the idea is not beyond reason. What if we encountered an ant species that did just that, perhaps because they were better raiders than their potential trading partners? The “buyers” exchange food for slaves, which they find a bargain. This would be an entirely biological arrangement, not introducing any new non-natural principle into biology. Some ants are natural-born slave-traders! No doubt this is deplorable of them, but it is biologically possible. They thus have a nice little economy going here—a system of exchange trading one sort of good for another.

I don’t think it is farfetched to suggest that human economies are analogous. Perhaps they even arose from some such primitive beginnings way back with our ancient ancestors in Africa. In any case, we can say that human productivity and the capacity for economic exchange are part of our biological nature. It turns out that the biological realm includes more than just natural generation and natural selection (in Darwin’s restricted sense); it includes the kind of intentional intelligent design and exchange that we find in human social groups. We can imagine our remote ancestors exchanging primitive tools for other tools or for food; we now do it with computers and cars. Thus from a lofty philosophical perspective economics is a branch of biology involving the basic twin generative processes: first make the product, then sell the product (ensure it is selected by purchasers). There is no discontinuity between genes and nature, on the one hand, and products and purchasers, on the other. There is a smooth transition from natural selection through artificial selection through economic selection. Darwin also included sexual selection in his list of types of selection; I am adding economic selection. Both of these are selection by conscious agents (peacocks and purchasers), but that doesn’t make them beyond the range of biology. Minds are a part of biology too. The dichotomy of culture and biology is artificial and misleading; economics belongs with both.[2]That is, economic culture is just another type of biological phenomenon. It is the same with business culture: that too is continuous with biology. Specifically, it involves the two generative components I have identified: creating the product and then marketing it, i.e. offering it up for selection by purchasers. The structure is the same. Markets are arenas of voluntary action, to be sure, but that doesn’t put them outside of biology or nature. In particular, economics is a generative science in the sense that biology is: it involves the generation of entities from raw materials and the generation of further entities by means of market forces. Production is like embryogenesis and buying and selling is like the selective survival of the fittest. Products go extinct if no one buys them, as animals go extinct if nature stops selecting them. We might even say that the Darwinian notion of natural competition is modeled on the notion of economic competition. Animals compete with each other in much the same way that products do. And of course the two intersect, as when animals are bought and sold (some breeds do better in the marketplace than others).

Just as Darwin’s theory is a theory of evolutionary change, so too economics is concerned with economic change—with how goods and services succeed each other in time. It is a dynamic science not a static science. The idea of a purely structural economics is a misguided one: economies are changing evolving structures just like animal species. The change can be slow judged by human standards, but the entire biological world is in constant flux; so too is the economic world. Supply and demand are forever changing. From a meta-economic point of view, then, economics shares the basic structure of biology (the same is true of linguistics and psychology—and even philosophy). In linguistics we are used to the idea that a grammar generates an infinite array of sentences—it is not merely a structural description; in economics too we should also think of economic mechanisms as generative—of products and of their adoption. A successful product is very like a thriving organism: there will be many instances of them and they will outperform the competition. This is the theoretical framework to adopt when considering the foundations of economics as a science. Economics is a generative biological science (so it is not like mathematics or logic). Capitalism, say, is a species of economic system that replaced feudalism, as mammals replaced dinosaurs. And it is still evolving into variant forms.

Let me suggest another analogy: verbal communication. A speaker is engaged on two generative tasks: (a) producing a grammatically well-formed sentence and (b) ensuring that she is understood by the hearer. The former does not entail the latter, which requires an additional generative effort—sufficient volume, getting the hearer’s attention, saying something interesting, etc. Similarly, the genes must produce an anatomically well-formed organism and one that will survive the pressures of natural selection—particularly, those arising from competition for resources and mates. Similarly again, a product must not only be functionally well designed but must also achieve market penetration in a competitive economic environment. The entrepreneur is like a speaker striving to be heard in a cacophonous world: she needs a sound product but also the means to be heard by potential consumers. It is necessary to generate supply and demand (hence advertising etc.). Whether an animal will survive depends on the world it confronts as well as on its internal structure; but the same is true of a product. A speaker faces the same problem: first produce a good sentence but then ensure it is heard and understood. You have to create understanding as well as what is understood. These are different (though connected) tasks. So economics is not just a generative science; it is a doubly generative science.[3]


[1]I discuss this in “The Language of Evolution”, Philosophical Provocations(2017).

[2]I defend this view in “Biology and Culture: an Untenable Dualism”.

[3]This essay is a sequel to my earlier essay, “Memes, Behavioral Contagion, and the Zeitgeist”.