I do sometimes wonder whether the appalling degradation in American culture, morality, and intelligence that we have winessed in the last twenty years (including in universities) was caused by the horrific events of 9/11. At the time I feared that the American reaction to these events might exceed in harmfulness the events in question. Can there be any doubt that American paranoia has increased markedly because of that day?
Is Shape Physical?
Shape is included on the traditional list of primary qualities, but that doesn’t settle the question of whether it is physical. Indeed the question is seldom raised: is the shape of an object a physical property of it? Nor is it an easy question to answer—largely because of vagueness in the word “physical”. Is geometry a physical science? It is not usually so described, since it deals in abstract objects. Such objects are ideal: perfect circles, perfect rectangles, etc. No physical object (so called) exhibits these properties, so it seems reasonable to say that perfect shapes are not physical. Shapes are mathematical abstractions imperfectly exemplified by physical objects. We apply geometry in physics, but the objects of geometry are not themselves physical entities (in so far as we know that means). Moreover, there are no laws of shape recognized in physics, as there are laws of gravity and electromagnetism: shape doesn’t act as a force producing motion. A physics textbook doesn’t have a chapter on the laws governing shape. Shape is irrelevant to gravity and electromagnetism: the mass of an object is relevant to its gravitational force but the shape is not. Physics would be essentially the same if every object had the same shape. So there seems every reason to deny that shape is physical. But does that imply that it is mental? Not at all, and the idea seems obviously wrong (short of generalized idealism). Shape is neither mental nor physical. It may be causally consequential but it is not thereby a physical property. Someone who believed that the world is fundamentally geometrical would not ipso facto be a physicalist (or materialist). Nor would it be correct to say that size, number, motion, and dimensionality are physical properties: they too belong on the mathematical side of things. Maybe it is necessary truth that anything that has such properties is a physical thing, but that by itself doesn’t entail that they themselves are physical properties (the same might be said of colors). One is then left wondering what indisputably is a physical property, if shape isn’t one. Is mass a physical property? But mass is defined in terms of inertia, which is a dispositional mathematical property (measured by how much force is needed to initiate motion). What about electric charge? But that too is dispositional and mathematical, and has historically been regarded as clearly non-physical (like gravity). Is it perhaps that no property is physical but that objects are what fall under that (alleged) concept? But in virtue of what—don’t we need some viable notion of a physical property? The very idea of the “physical” starts to slip through our fingers once we focus hard on these questions. It is entirely conceivable that the whole subject called “physics” has no intelligible notion of the physical—and that this is no objection to the science known by that name. Here we reach a conclusion that has persistently threatened the would-be philosophical physicalist: we simply have no workable general notion of the physical. Shape might have seemed to provide at least a paradigm of the physical, but that has turned out to be a frail reed. All we are left with is the idea that a physical property is what the subject called “physics” talks about, but that is a variable and pragmatic matter. We have no clear idea of what a physical property is intrinsically—unless we decide to stipulate that everything is to be counted as physical, the term being equivalent to “real”.
I say all this to make a metaphysical point, viz. that we should stop trying to divide the world up into the physical and the non-physical. We can talk about what is mind-dependent and what is mind-independent, but we should drop the assumption that anything can be usefully described as “physical”. This means that falling under that term is no measure of ontological primacy or clarity: we can’t contrast other types of putative property with physical properties and hope to formulate a useful distinction. We can’t characterize mental or moral or mathematical properties as “non-physical” and hope to join a genuine metaphysical debate: for there is simply no such thing as the category of “the physical”. We might have supposed that shape would give us a firm foothold, but shape turns out not to be a good candidate for fixing the notion of the physical. The word “physical” has an everyday use (or several such uses) but as a theoretical term it lacks any clear definition, as has frequently been pointed out. That is why we hesitate when asked if shape is physical—as we do when asked if color is physical (or beauty or moral rightness). Let me put it more forcibly: if we can’t say whether shape is physical, we may as well retire the term from serious theoretical employment. It’s like asking whether shapes are holy: the term belongs to an outmoded theoretical framework and survives mainly as a term of approbation. Are circles more holy than rectangles? Are circles less physical than irregular figures? Such questions have no meaning, because “holy” and “physical” lack determinate content. I would say that shapes are clearly not physical if we mean by “physical” something like “tangible and concrete” or “relating to the body” (as the OED has it): for shapes are abstract, and they are not peculiar to the body. Nor are they physical in the sense that they are perceived by the senses: they may sometimes be imperceptible to the senses, and they may never be perceived as they really are. Shapes are just not intuitively physical (though intuitions about the concept of the physical are notoriously slippery). So the world contains properties that are not mental and not physical, and these properties are among the most salient in our experience. We can intelligibly ask whether everything real reduces to the standard list of primary qualities, but that is not the same question as whether everything real reduces to the physical—which is pretty much vacuous. I can imagine a “shape-ist” metaphysics in which geometrical form is taken to be the most basic property in the universe, but it would be misguided to describe this as a form of physicalism. Maybe everything comes down to the motion of shaped objects, but it is not helpful to describe this as a type of physicalism. The doctrine known as “physicalism” survives largely on the lack of clarity in the term: we should abolish it and speak directly of specific kinds of properties such as shape and color. Whether these properties count as physical is an empty question best ignored. [1]
[1] The familiar (and good) point that gravity is not physical according to traditional notions of the physical (deriving from mechanism) is the usual way of questioning the utility of the term “physical”; my point here is that even shape poses problems for that term. In what sense precisely is shape to be deemed physical? Would Plato and Pythagoras so characterize it? It is hugely tendentious to count circularity as a physical property and is not remotely warranted by tradition—you may as well declare that beauty is a physical property because physical things (whatever that may mean) have it.
Social Interactions
What is the nature of a social interaction? The subjects interacting have their own nature, but what about the interaction itself? It will no doubt reflect the nature of the interacting subjects, but it may be expected to have a nature of its own. There have been varying views of this, more or less explicit, in social psychology and elsewhere, which I will list. The simplest view might be called causal: the idea would be that individual subjects causally interact in the manner of physical bodies, so that there is nothing distinctive about human social interaction—it’s all just pushes and pulls. A second view brings in the concept of information: in a social interaction information is exchanged, linguistically and otherwise, so that the informational state of each subject is altered. A third view might be called epistemic: each subject has a certain kind of knowledge of the other, typically mutual knowledge, as in “x knows that y knows that x knows etc.”. Fourth, there is the interpretative view: each subject is engaged in interpreting the other’s behavior, linguistic and non-linguistic, either radically or domestically, using psychological and semantic concepts. Fifth, the relation is one of influence: one subject influences another in certain ways, say by inducing conformity. Sixth, the idea of power is invoked: subjects exercise power over other subjects, sometimes detrimentally, this being the essence of social interaction. Seventh, the notion of competition is added: individuals compete with each other, biologically or economically or in some other way, the result varying from death to status superiority. Eighth, cooperation is taken to be the essence of social interaction: people bond and band together to achieve a joint goal, as in hunting parties, political parties, and party parties. Ninth, we have the existentialist view of social interaction: individual subjects of consciousness confront each other in their radical freedom, sometimes in bad faith, possibly in a condition of authenticity. Tenth, there is the theatrical conception: the nature of social interaction is inherently dramatic or histrionic, as each party plays a part on the social stage. Eleventh, we have what might be called the spiritual theory: social interaction is a meeting of souls, an escape from spiritual solitude, and a glimpse into the inner spirit of the other. Finally, there is the moral conception: social interaction is the exercise of moral duties, an expression of virtues and vices, the place where our moral nature shows itself.
I take it these positions will seem familiar, with familiar names attaching: Shakespeare, Goffman, Rousseau, Marx, Sartre, Foucault, Quine, Davidson, Darwin, Kant, Hume, and many more. Clearly, not all of these views are in competition with each other, except perhaps as declarations of emphasis; but we can see that different concerns, practical and theoretical, lead to different conceptions of the nature of the social. One might adopt an eclectic position: all the views mentioned have an element of truth to them, social interaction being a multi-dimensional affair. But one might hope for something a bit more organized and systematic; one might seek to identify the kernel of social interaction, from which other features flow. So I will suggest a conception that seems to me to capture the basic character of the social: it combines the epistemic, the existential, and the theatrical conceptions. In a social interaction we possess a certain kind of mutual knowledge, as we recognize the way the other is forming a view of our views of him or her; and so on indefinitely. I know that you know that I know that you can’t be trusted, say. This doesn’t apply to social interactions involving animals or small children, but it is the bane of adult human social interactions: we are always wondering what the other thinks of us, especially with regard to what we think of them. The existentialist component comes in via free action: we see the other as a free agent who may or may not act as we would wish. We are aware that the person we are interacting with may not act as we desire—that she might, say, suddenly decide to leave, or to end the relationship. This awareness of freedom hovers over all our social interactions: they are nothing like our interactions with inanimate objects. Anxiety is the natural outcome, so the social encounter is always fraught, always tenuous. The theatrical component concerns our methods for handling social interactions: we have to construct a social self (or selves) that we present to others for their consideration and treatment. We must play a part that will oil the encounter, produce the requisite attitudes in others, and manage the freedom that we know hovers ominously in the background. Thus our social interactions combine a special type of mutual knowledge, an understanding of freedom, and theatrical skill. That is their basic structure, from which other features emanate. And it is what might be lacking in abnormal cases—a certain package of cognitive competences. This could come about by way of upbringing or innate endowment, resulting in social incompetence or worse. And it is not as if this stuff is easy, some people being much better at it than others. It is a developed skill, a specific mental module, with a rich internal structure. It grows in the child and can atrophy in the adult. Disease can disrupt it. Practice helps. It needs nurturing.
There should really be a philosophy of social interaction—a systematic attempt to delineate its structure. It would identify the basic components and seek to derive the social phenomena we observe in various contexts—economic, marital, athletic, musical, familial, pedagogical, etc. Philosophers have analyzed the human subject and human society, but they have not developed a branch of study dedicated to the nature of social interaction as such, except as this might serve some other agenda. Social psychology, too, might benefit from this kind of philosophical attention. It never hurts to be clear about what you are talking about. [1]
[1] When I studied social psychology in the late 1960s there was much concern with issues of obedience and conformity, possibly as a consequence of prevailing social conditions. But I don’t recall any preliminary discussion of the general nature of a social interaction, so the subject matter was left vague and indeterminate. If I were teaching social psychology today, I would spend some time exploring different conceptions of social interaction: what is it to interact socially with another person? And I would frame the issue as concerning a certain mental competence, Chomsky-style. What is this competence, how is it acquired, how is it expressed, what are its pathologies, how might it be improved? The philosopher might be useful here.
I happened to be watching a repeat of SNL last night and was struck again by a sketch about cancel culture. A preening pair, woman and man, were congratulating themselves on their activities in canceling young children. The kids were aged from 3 to 5 and the pair were relishing their destruction of the future lives of these miscreant infants for saying things deemed “problematic”. It really wasn’t funny except in the darkest way. It nailed the psychology of this recent exercise in violence perfectly.
Knowledge of Color
As colors have a metaphysics, so they have an epistemology. In addition to ordinary empirical truths about what colors objects have, there are also general truths stating a priori necessities: for example, “Orange is closer to red than to blue”, “There cannot be reddish green”, “Nothing can be white and transparent”, and “Nothing can be red and green all over”. [1] There is also knowledge of what colors in themselves are (“knowledge of things”): we know what red is, for example. We know quite a lot about colors before we even get to questions about the empirical distribution of colors among objects. Compare shapes: we also know a lot about shapes, both what they are and general truths about them, in addition to propositions about the shape of particular objects. This knowledge is also of a priori necessities. But there is a difference between shape and color: there is no analogue of geometry for color. There is no mathematical science of color comparable to the mathematical science of shape. There are no color theorems analogous to the theorems of Euclid’s Elements. There is barely a mathematics of color at all, though colors do form an abstract structure. Nor can we conceive of colors as derived from anything analogous to lines, as geometrical figures are so derived: you can form circles and rectangles with simple lines, but you can’t form red and green from a single basic chromatic primitive. Colors just don’t have the requisite degree of structure or quantitative character to allow a color geometry. Sounds are closer to shapes in this respect, as evidenced by musical theory: scales and keys are derived from mathematical relations of pitch (pitch being like line, constructively). But colors aren’t structured like closed many-sided figures, and there is nothing like angle in color space. So our knowledge of color doesn’t include anything comparable to geometrical knowledge, despite being a priori and necessary. Colors are not mathematizable in the way shapes are.
One might speculate that this is because colors are less objective than shapes. If colors are really experiential properties in disguise, then maybe it is the non-mathematical nature of experience that underlies the absence of a geometry of color. The same would not be true of shape, since we can separate objective shape from subjective shape: geometry is about objective shape not experienced shape; and maybe experience of shape is not susceptible to mathematical treatment either. But that kind of subjectivism doesn’t seem correct in the case of knowledge of color: such knowledge is not knowledge of experience as such—we are not thinking about experiences of color when we recognize general truths about color. Perhaps there are deep a priori connections between facts about color and facts about experiences of color, but it seems wrong to suppose that truths concerning color are simply analyzable as truths about experience—a color isn’t an experience! We have experiences of color, but the color of an object is not an experience in the perceiving subject. So the character of our knowledge of color is not immediately explicable in terms of our knowledge of color experience. Further, if we ask why experience of color is not mathematizable, the answer must surely advert to what such experiences are of, viz. colors: but this returns us to the non-mathematical character of colors themselves. There is much more hope of a mathematics of shape experience, given that such experiences are of shapes, which have a developed geometry to call their own. It appears, then, that it is colors as such that resist mathematical treatment: being red is not like being an equilateral triangle—the property itself lacks internal mathematical structure. This is just a basic ontological fact.
Here is another difference between color and shape: there is nothing analogous to space in the color case. What I mean by this has to be carefully stated: shape can be viewed as a mode of space, but color can’t be viewed as a mode anything analogous to space. Space, like matter, has extension (at least in commonsense physics), and shapes are modes of extension; but there is nothing analogous that has some chromatic property of which the several colors can be viewed as modes. A red object (isolated from other colored objects) is not surrounded by a sea of color, in the way a square object is surrounded by a sea of space. Shaped objects exist in a medium that shares their geometrical nature, but colored objects don’t exist in a chromatic medium: space isn’t colored! The color is simply in the object not borrowed from the medium in which it exists. Space and shape are natural partners, but space is not a progenitor (or twin) of color—and neither is there anything else that plays the role of space in relation to color. There is not some milky stuff, say, that houses the colors we observe in objects. Given space, shape is not a surprise; but space doesn’t prepare us for color, which appears as a radical addition. Color just seems plonked down in space with nothing comparable to support it. There is no chromatic ether.
Knowledge of color might be cited as a basic type of knowledge that could illuminate other types of knowledge. Puzzles raised by other types of knowledge might have precursors in our knowledge of color, in particular knowledge of what is necessary and a priori. Wittgenstein compares mathematical knowledge to color knowledge, hoping thereby to demystify it. [2] The comparison might help resist platonic conceptions of mathematical knowledge, given that colors are relatively “concrete”. Certainly we can use color knowledge to argue for the non-uniqueness of mathematical knowledge in its synthetic a priori character: mathematical knowledge doesn’t stand apart from all other types of knowledge in having that kind of status. Even perceived colors can give rise to synthetic a priori truths—not just abstract platonic universals. But the other area that might be compared to color knowledge is knowledge in ethics, which is often compared to mathematical knowledge. It is felt that ethical knowledge needs all the help it can get in securing its epistemic credentials, and mathematical knowledge is then wheeled in as a precursor or partner in crime. The idea certainly has strong appeal for a moral realist convinced that moral knowledge is a species of a priori knowledge. But the color case might be an even better model for ethics, because it is less rigorous than mathematical knowledge and, well, less mathematical. The critic will point to the asymmetry in respect of proofs and general formal sophistication, thus pooh-poohing the comparison to mathematics; but the color case mirrors ethics more closely in these respects. Ethical knowledge resembles our knowledge of color in being synthetic and a priori, and neither is at the level of mathematical science. This is not to downgrade them: it is merely the way they are given the properties and facts concerned. Colors are just not intrinsically susceptible to mathematical treatment (save very superficially), and there is no reason they should be; analogously, moral values are not susceptible to mathematical treatment, and there is no reason they should be. So color and morality belong together epistemologically (we could also bring in sounds and even tastes and smells). In both cases we have a faculty of knowledge that delivers insight into the subject matter in question, thus delivering types of knowledge traditionally described as synthetic a priori (i.e. not analytic and not derived for experience). Anyone seeking to question the status of moral propositions in these respects must explain why they decline to take the same line for propositions about color. It turns out that synthetic a priori knowledge is quite common (and indeed commonplace) and not confined to the supposedly elevated areas of mathematics and morality. Even the humble colors, perceived by human and beast alike, can give rise to such knowledge. Being right is not so far from being red, epistemologically speaking. [3]
Colin McGinn
[1] Wittgenstein discusses these kinds of propositions in Remarks on Colour (1977).
[2] See Zettel (1967): “’There is no such thing as reddish green’ is akin to the sentences we use as axioms in mathematics” (section 346).
[3] Readers of my 1983 book The Subjective View may notice some departures in what I write here, though I think they are largely a matter of emphasis.
Colors and Powers Again
Locke distinguishes primary qualities from powers to produce sense impressions of them in perceivers, but he thinks that secondary qualities are “nothing else, but several powers in them, depending on these primary qualities…to produce several different ideas in us”. [1] That is, he identifies colors with powers to produce states of mind: that is what a color is—a causal power of a certain sort. I am going to make two rather brutal criticisms of this doctrine. The first is that causal powers are invisible but colors are not. Suppose I see an object as square: that quality is visible to me, but the power to produce an impression of square is not so visible. I don’t see an object ashaving such a power—I simply see it as having the geometric property of being square. As Hume taught us, we have no sense impressions of causal powers—though objects have them. Powers are actually rather mysterious things involving potentiality, and they concern relations between objects and other objects (in this case objects and perceiving minds). They aren’t intrinsic manifest qualities; they are rather like modal properties such as being possibly square. They aren’t things the senses can resonate to. So Locke’s theory implies that colors are invisible! Nowhere does he acknowledge that consequence, and it is indeed startling: surely we want a theory of color to be consistent with the visibility of color. I suppose he could just accept the consequence, but it is a hard bullet to bite. Maybe colors have the power to produce impressions of themselves, as shapes do, but they are not identical to such powers. In fact, the power to produce sense impressions depends on certain forces that exist in objects, but forces are not perceptible: we don’t perceive electrical or gravitational forces, only their effects. Yet we see colors quite plainly: they are nothing like hidden powers or potentialities.
Second, external physical objects are not the only things with such powers. Minds and brains have them too. Your mind has the power to produce ideas of secondary qualities in you, as it does when you hallucinate. In fact, it must have such powers if external objects are to elicit sense experiences in you; the external object alone cannot do this. The brain too must have the power to generate sense impressions, which it demonstrates all the time. But if colors are identical with such powers, then minds and brains are colored. They have these powers in virtue of possessing appropriate primary qualities, just like external objects, so they have the property Locke identifies with color: but they don’t have the very color that this power would entail. The mind isn’t red when it exercises the power to produce impressions of red, and neither is the brain. It is easy to see what is going wrong here: having the power to produce sense impressions is just too broad a condition to capture what color is. Couldn’t a super-scientist have such a power without having the colors that allegedly go with it? Nor will it help to limit the power to the surfaces of external objects, since they too could have such powers and not be colored: they might be little minds or brains. Having the power to elicit experiences of red will never add up to being red—merely to the ability to cause experiences thereof (almost anything can do that in the right circumstances). The condition is clearly far too weak.
So the Lockean theory of color renders color (a) invisible and (b) a property of the mind-brain. As I say, brutal.
Colors and Powers
According to Locke, colors are nothing but powers in objects to produce ideas in our minds. He writes: “What I have said concerning colours and smells, may be understood also of tastes, and sounds, and other the like sensible qualities; which, whatever reality we by mistake, attribute to them, are in truth nothing in the objects themselves, but powers to produce various sensations in us, and depend on those primary qualities, viz. bulk, figure, texture, and motion of parts; as I have said.” (Essay Concerning Human Understanding, Book II, Chapter VIII, section 14) There is, he tells us, no “resemblance” between these sensations or ideas and the objective ground of the power, as there is in the case of primary qualities, and without minds to interact with the powers there would be no color (etc.) in the world. To say that an object is red is just to say that it has the power to produce sensations of red in us: that is, colorless objects made of colorless minute particles happen to cause in us a certain type of sensation, and that is all there is to color—it has no mind-independent existence.
But two questions may be raised about this doctrine, appealing though it is. The first is that a given object has several such powers: it may produce sensations of red in one set of perceivers and sensations of green in another set (and so on for the other colors). It doesn’t have a unique idea-producing power but many such powers (it could even produce ideas like those produced by the other senses). Yet there is only one set of primary qualities underlying this multiplicity of powers. This prevents us from identifying the color with the primary quality basis, on pain of identifying the colors with each other (same basis for each power and hence sameness of color). It isn’t the power in the object that is fixing the color of the object but its relation to the minds of perceivers. Second, how could a colorless object have the power to produce sensations of color? Nothing about the object itself explains the power it has to excite color sensations, let alone specific color sensations. It is, we might say, chromatically impotent. It would be a type of miracle if primary qualities had the power to produce sensations of quite different qualities. The only sense in which objects have such powers is that minds have corresponding powers: the mind has the power, when interacting with colorless objects, to generate sensations of color—the power comes from it not the external object as such. The power of which Locke speaks is really a relational power not an intrinsic power. Intrinsically the object is powerless to produce color sensations; whatever power it possesses is conferred on it by perceiving minds. Locke should have said that colors consist in the power of our mind to impose colors on the world—powers in the mind not powers in objects. Does a square object have the power to produce sensations of a round object? Well, it can produce such a sensation if the perceptual system misfires, but it has no intrinsic power to do any such thing—as it has to produce a sensation of a square object. It just happens to cause (partially) a sensation of roundness; the real work is done by the perceiving mind—it has the power to respond with roundness perceptions to a square object. Similarly, colorless objects can elicit sensations of color, but only because minds are so set up that they can generate sensations of color in the presence of things that have no color. The external primary qualities play a minimal causal role, and considered in themselves have no power to produce sensations at all. Indeed, it is conceivable that there be no such objects and yet the mind has the power to generate the full panoply of colors from within its own resources (color sensations in a vat). In fact, we are already in a situation close to this in that we have colored mental imagery that is elicited by no external object—no primary qualities are triggering this kind of “perception”. The external object in the perceptual case merely triggers a pre-existing power of the mind; it is not the locus of the power to bring color sensations into the world. [1]
If we say that water has the power to dissolve salt, we mean that water has objective properties that explain how the power is exercised; but if we say objects have the power to cause color sensations, we can’t provide any such explanation. This is because objects are powerless in this regard; the mind is the origin of the power in question. Imagine a world in which there are simple objects having just two properties and yet these objects are perceived by minds as being rich and complex, endowed with (say) a thousand properties. It would be bizarre to suggest that the objects have the power to produce the full range of sensations available in this world—that power properly resides in the minds that exist in it. It would be quite wrong to say that the properties perceived are nothing but powers in the objects to produce sensations, with their impoverished two-property profiles. The objects have no such intrinsic power, though they have the weak relational power of being able to interact with minds that do have the power to perceive the full range of a thousand properties. In a way Locke undersells his own subjectivist position, which is that the mind is the origin of secondary qualities not the external world. At the least he should have distinguished between the weak sense of power and the strong sense, maintaining only that objects have only a weak power to cause sensations. Primary qualities, by contrast, have a strong power to produce sensations because of that “resemblance” he mentions, but secondary qualities are only weakly connected to the objective nature of external objects. They are connected in roughly the sense in which sugar has the power to taste bitter if the taster’s sense organs are deranged in some way, or in which red objects have the power to appear yellow if there is something wrong with your eyes. The relation expressed by “x can trigger y” is much weaker than that expressed by “x has the power to y”.
This matters because it affects the strength of subjectivity of Locke’s basic doctrine. If we identify colors with powers-in-objects, then we accord them a degree of objectivity not intended by the basic metaphysics; but if instead we identify colors with powers-in-the-mind, then we fully endorse the fundamental thesis that colors are purely subjective, i.e. originate in the mind and are then imposed or projected onto external things. Here is Locke in full flight: “The particular bulk, number, figure, and motion of the parts of fire, or snow, are really in them, whether anyone’s senses perceive them or no: and therefore they may be called real qualities, because they really exist in those bodies. But light, heat, whiteness, or coldness, are no more really in them, than sickness or pain is in manna. Take away the sensation of them; let not the eyes see light, or colors, nor the ears hear sounds; let the palate not taste, nor the nose smell, and all colours, tastes, odours, and sounds, as they are such particular ideas, vanish and cease, and are reduced to their causes, i.e. bulk, figure, and motion of parts.” (ibid, section 17). That use of “reduced” is perhaps ill advised, suggesting as it does that secondary qualities, and ideas of them, are reducible to primary qualities of external things, which would make them as real as primary qualities in general. But it is clear that Locke intends to maintain that colors (etc.) are mere subjective projections not at all inseparable from matter—they arise from powers of the mind not from powers of matter. It is only in a very weak sense that we can say that objects have the power to produce ideas of secondary qualities, as weak as saying that manna has the power to produce sickness and pain, or a spear has the power to be thrown. The truth is (according to Locke) that colorless particles interact with our colorless sense organs in such a way as to activate the latent power of the mind to generate colors in all their glory. The power to produce color sensations is a mental power not a power of material objects considered in their own right. Perhaps Locke was subliminally influenced by his opposition to innate ideas: for if colors originate in the mind, how can ideas of them be derived from perception of external objects? At any rate, one who sympathizes with Locke’s metaphysics of color has reason to dislike his official object-centered formulation of the doctrine. The powers that give rise to colors are in the mind not in the external world. [2]
[1] Much the same can be said about the dispositional formulation of color subjectivism: objects have many color dispositions and no object has such a disposition intrinsically. Rather, minds have dispositions to see the world as manifesting various colors—that is where the disposition originates. Objects are merely disposed to trigger such mental dispositions in the sense that they can trigger them in certain conditions. The ontological work is done by the mind not the world.
[2] None of this is to deny that matter might be the origin of the mind’s power to produce colors; it is just that the material objects of perception are not the locus of the power to bring colors into being. Put broadly, Locke (and his followers) are putting too much emphasis on the powers of objects and neglecting the vital contribution made by the mind.
