More on Color

Colored Surfaces: A Puzzle

Colors appear to be onthe surfaces of things. The surface seems saturated with color, as if the color has been painted on. Colors seem as much an intrinsic property of surfaces as textures. They are not experienced as properties of the perceiver’s body or of the intervening medium. They coincide with the object spatially.[1]Yet, according to tradition, they are projections of the mind, arising from the perceiver’s inner resources: they are transferred from inside to outside—from “in here” to “out there”. In the cinema we experience the film image as on the screen in front of us, though it emanates from somewhere behind us in the projection room. Similarly we see color as inhabiting the surface of objects while in fact it issues from somewhere in our minds (unlike shape or texture). According to some views, colors are dispositions to produce experiences; but dispositions are not perceived as if they are onthings, so there is a mismatch between appearance and reality. Colors are creatures of the mind and yet are perceived as distal features of objects.

The point I want to make is that they are unique in being thus outwardly perceived: among so-called secondary qualities they are the only ones experienced as being literally onthe object of perception. They are the only secondary qualities experienced as objective features of things (in one sense of “objective”). This is puzzling. Why aren’t they experienced as the subjective phenomena they really are, like other secondary qualities? Couldthey be so experienced? We don’t perceive smells and tastes as on things: smells are experienced as in our nose not in the remote object, and tastes only coincide with the object tasted because it is typically in our mouth (it would be different if we tasted things remotely). Likewise we don’t hear sounds as if they are on objects—we don’t project the sound out onto the source of the sound (the noise is loud not the object making it). We hear sounds as in the proximity of our ears (consider the flash of a distant cannon followed a few seconds later by the sound of the shot). Indeed, we hear sounds not objects, so we don’t experience sounds as remote qualities ofobjects. In the case of heat and cold we locate these qualities in our body not in the object. It is true that hot and cold objects are typically touching the body, so that the qualities are experienced as spatially coincident with the object, but again that is a contingent circumstance—and there are cases in which we have such sensations emanating from remote objects (e.g. the Sun). When I feel the heat of a remote object I don’t project the hotness onto the object; I feel the hotness in the region of my body. The object causes my body to feel this way, to be sure, but I don’t perceive it as having the sensory quality in question on its surface. Thus we are not so inclined to make an error about the status of such secondary qualities: we recognize that they are subjectively constituted (unless we are philosophically opinionated). There is no illusion of objectivity for these cases. Someone might be of the opinion that objects are intrinsically hot or cold, independently of perceivers, but it would be pushing it to claim that they experience these qualities to be onobjects, as they perceive colors to be on them. I perceive the Sun as yellow on its surface, but I don’t perceive it as hot on its surface.

It is an interesting question whether this is a contingent truth or a necessary truth. Could there be a perceiver that experienced color as he experienced other secondary qualities? Is the perception of color necessarily outward in the way it actually is? Here are two reasons to doubt that. First, we can ask whether all organisms that perceive color perceive it as intrinsically qualifying the surface of objects. Do insects see colors as intrinsic properties of surfaces? Might they not have sensations of color that are detached from sensations of surfaces, perhaps because they have deficient spatial perception? Color sensations are triggered in them by external objects, but they don’t engage in full-blooded projection onto distal surfaces, so that they perceive color rather as we perceive smells or sounds. This seems logically possible. Second, not all of human color experience involves distal projection onto physical surfaces—consider mental images, after-images, and those sensations you get when you press your eyeball or close your eyes. In these cases you don’t experience a remote surface as suffused with color, alongside shape and texture; the experience is felt as more internal, more subjective. If so, it would be possible for objects to elicit such color sensations without the perceiver painting their surfaces with color. So color couldbe perceived in the way other secondary qualities are perceived, not as it is now for us in ordinary color vision.

And herein lies the puzzle: why is color perceived as on surfaces, suffusing and saturating them, as if it were an objective property like texture, when it could be perceived as other subjective qualities are? Why is it accorded special treatment? Why is the projection so extreme? One possible answer is biological utility: it is more effective or convenient to experience color in this external objectifying way. But why is that—why does color differ from other secondary qualities? Why don’t they follow the model of color if it is so effective and convenient? And what does this biological utility consist in—what selective advantage does it incur? Another possible answer is that vision has a special kind of phenomenology that requires the qualities that are perceived to be perceived as distal. But why should that be, given that not all of visual experience involves projection onto remote surfaces? It is perplexing why we perceive color as a property of surfaces in the way we do—why we perceive colors as onobjects. Colors are not really on surfaces, objectively speaking, so why make an error in color perception when other secondary qualities involve no such error (or not one of the same magnitude)? Why paint the world with color it doesn’t have when you could stick to a mode of experience that involves no such effort and illusion? Why not see the world more as you feel it or smell it, without the projection of secondary qualities beyond their proper sphere? This is the puzzle presented by colored surfaces.

Colin McGinn

[1]If you place a colored filter in front of a white surface you will see the surface as having the color of the filter. The eye projects the color from the proximal filter onto the remote surface. Thus you see the surface as being (say) pink in virtue of an act of projection performed by the visual system. But projection operates even in cases where there is no such intervening medium.