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Can Experience Commit Category Errors? A third version of the argument from charity alleges that according to projectivism, visual experience commits not just a mistake but a category mistake, by representing external, material objects as having properties that can occur only within the mental realm.19 Such a mistake is thought too gross for visual experience to commit. It is not clear whether it is a necessary or merely contingent fact that external objects do not possess the sorts of property we understand colours to be; hence, it is not clear whether the mistake projectivism attributes to visual experience is categorial or merely systematic. But even if it were a category mistake, why should this necessarily be considered a difficulty for projectivism? The assumption underlying the objection is that it is somehow extremely difficult to see how experience could commit a category mistake. But as the following remark of Wittgenstein suggests, just the opposite seems true. Let us imagine the following: The surfaces of the things around us (stones, plants, etc.) have patches and regions which produce pain in our skin when we touch them. (Perhaps through the chemical composition of these surfaces. But we need not know that.) In this case we should speak of painpatches just as at present we speak of red patches. 0 In the normal experience of pain, pain is not perceived as a quality of its cause. As Wittgenstein remarks, however, this seems to be thanks only to the fact that the normal causes of pain constitute such a heterogeneous class. Were pain to be caused solely, say, by certain specific patches on the surfaces of plants, we might well experience pain as being in the plant, much as we now experience its colour. Far from being unimaginable, then, it would seem that nothing but a purely contingent fact about our experience of pain stands between us and a category mistake just like the one that projectivism portrays us as committing about colour. INTERPRETING COLOUR DISCOURSE Thus far we have discussed colour concepts as they are exercised in the representational content of colour experience. Let us turn, somewhat more briefly, to the content of ordinary discourse about colour. We assume that ordinary discourse about colour reports the contents of visual experience. The most plausible hypothesis about what someone means when he calls something red, in an everyday context, is that he is reporting what his eyes tell him. And according to our account, what his eyes tell him is that the thing has a particular visual quality, a quality that does not actually inhere in external objects but is a quality of his visual field. We therefore conclude that when someone calls something red, in an everyday context, he is asserting a falsehood. Indeed, our account of colour experience, when joined with the plausible hypothesis that colour discourse reports the contents of colour experience, yields the consequence that all statements attributing colours to external objects are false. One would be justified in wondering how we can accept this consequence, for two related reasons. First, we will clearly want to retain a distinction between ‘correct’ and incorrect' colour judgements, distinguishing between the judgement that a fire-hydrant is blue and the judgement that it is red. And it seems a serious question what point we error theorists could see in such a distinction. Second, it seems perfectly obvious that colour discourse will continue to play an indispensable role in our everyday cognitive transactions. Yet how are we error theorists to explain this indispensability, consistently with our claim that the discourse in question is systematically false? We shall begin with the second question. The Point of Colour-talk Consider one of the many harmless falsehoods that we tolerate in everyday discourse: the statement that the sun rises. When someone says that the sun rises, his remark has the same content as the visual experience that one has when watching the horizon at an appropriately early hour. That is, the sun actually looks like it is moving, and that the sun moves in this manner is what most people mean when talking about sunrise. So interpreted, of course, talk about sunrise is systematically false. When someone says that the sun rises, he is wrong; and he usually knows that he is wrong, but he says it anyway. Why? When one understands why talk about sunrise is false, one also understands that its falsity makes no difference in everyday life. We do not mean that nothing in everyday life would, in fact, be different if the sun revolved around the earth, as it seems to. No doubt, the tides and the phases of the moon and various other phenomena would be other than they actually are. But those differences are not missed by the ordinary person, who does not know and has no reason to consider precisely how the tides and phases of the moon are generated. Consequently, someone who has a normal background of beliefs will find no evidence in everyday life to controvert his belief that the sun revolves around the earth. That belief will not mislead him about any of the phenomena he normally encounters; and it will in fact give him correct guidance about many such phenomena. His judgements about the time of day, the weather, the best placement of crops, the location of glare and of shadows at noon, will all be correct despite being derived from premisses about a stationary earth and a revolving sun. Indeed, he is likely to derive more true conclusions from his belief in a revolving sun than he would from a belief in a rotating earth, for the simple reason that the consequences for earthlings of the former state of affairs are easier to visualize than those of the latter, even though those consequences would be the same, for everyday purposes. Talking about horizon-fall rather than sunrise would thus be downright misleading, even though it would be more truthful. Only an undue fascination with the truth could lead someone to reform ordinary discourse about the sun. Talk about colours is just like talk about sunrise in these respects. That is, life goes on as if objects are coloured in the way that they appear to be. Experience refutes few if any of the conclusions derived from beliefs about objects' colours; and many true conclusions are derived from such beliefs. Most of those true conclusions, of course, are about how objects will look to various people under various circumstances. And these conclusions are extremely useful in everyday life, since one's ability to communicate with others and with one's future selves about the external world depends on the ability to describe how various parts of that world appear. The point is that such conclusions are more easily and more reliably drawn from the familiar false picture of colours than they would be-by the ordinary person, at least-from the true picture of wavelengths and spectral-reflectance curves. Why, then, should one replace such a useful false picture with a true but misleading one? Correct vs. Incorrect Colour-talk The case of colour differs from that of sunrise in one important respect. The sun never seems to do anything but move in a regular arc across the heavens, whereas objects often seem to have different colours in different circumstances. The ordinary speaker therefore finds himself drawing a distinction between the colours that objects really have and the colours that they only seem to have on some occasions. How can we countenance this distinction between real and illusory colours, given that our theory brands all colours as illusory?21 The answer is that classifying an object by the colour that it appears to have under so-called standard conditions is the most reliable and most informative way of classifying it, for the purposes of drawing useful conclusions about how the object will appear under conditions of any kind. Obviously, classifying an object by how it appears in the dark is not at all informative, since all objects appear equally black in the dark, even though they appear to have different colours in the light. Hence one can extrapolate an object's appearance in the dark from its appearance in the light, but not vice versa. The same is true-though to a lesser degree, of course-for other non-standard conditions. For instance, distance tends to lend a similar appearance to objects that look different at close range; coloured light tends to lend a similar appearance to objects that look different in daylight; and so on. The common-sense calculus of colour addition and subtraction therefore enables one to infer an object's appearance under nonstandard conditions from its appearance under standard conditions, but not its appearance under standard conditions from that under non-standard conditions. That is why one set of conditions, and the accompanying colour-illusion, are privileged in everyday life. There are notable exceptions to our claim about the varying informativeness of various colour appearances. But these exceptions actually support our explanation of why particular colourillusions are privileged in ordinary discourse, because consideration of them leads the ordinary speaker to reconsider the distinction between true and illusory colour. Some pairs of objects that appear to have the same colour in daylight-say, green-can appear to have different colours under incandescent lighting, where one may appear green and the other brown.22 In these cases, how an object appears in daylight is not an indication of how it will appear under other less standard conditions. Yet in these cases, one begins to wonder whether the object has atrue’ or standard colour at all. If an object’s apparent colour does not vary, from one set of conditions to the next, in the same way as the apparent colour of objects that share its apparent colour in daylight, then one is tempted to say that the object does not have any one colour at all. Consider the object that looks green in daylight but brown in incandescent light, where most other objects that look green in daylight still look green. Is the object really green? really brown? Does it have any single `real’ colour at all?23 Here intuitions diverge and ultimately give out. The reason, we think, is precisely that the commonsense notion of an object’s real colour presupposes that it is the one apparent colour from which all its other apparent colours can be extrapolated, by fairly famili