Introduction: Historical and Contemporary Views On The Visible/Non-Visible Distinction, and What the Visible/Non-Visible Distinction Is Not

Introduction Historical and Contemporary Views On The Visible/Non-Visible Distinction, and What the Visible/Non-Visible Distinction Is Not 1 The Project In this thesis I define a kind of looking, phenomenal looking, which is individuated in terms of differences in visual phenomenal character. I discuss some issues concerning the properties that objects phenomenally look to have. The first issue I discuss concerns the range of properties that objects phenomenally look to have. I argue that objects phenomenally look to have only colours and positions. The second issue concerns the kinds of position properties that objects phenomenally look to have. I call the position properties that objects phenomenally look to have phenomenal position properties. I argue that phenomenal position properties are not observer-relative properties such as being to the left of me and being to the right of me, but instead absolute, nonrelational properties. I call this view concerning phenomenal position properties primitivism. The third issue concerns whether objects have phenomenal position properties. There is some similarity between the arguments over whether objects have phenomenal position properties and the arguments over whether objects have the colour properties that they phenomenally look to have. I argue that necessarily objects do not have the colour and position properties that they phenomenally look to have. The fourth issue concerns whether the position properties that objects phenomenally look to have consist of x, y and z coordinates, or only x and y coordinates. I argue that the position properties that objects phenomenally look to have consist of x, y and z coordinates. The fifth issue concerns how objects would phenomenally look to beings with more coarse-grained discriminatory capacities than us. For instance, suppose that patch1 and patch2 phenomenally look red1 and red2 respectively to one. Consider a being, say a dog, which cannot discriminate the colour that patch1 phenomenally looks from the colour that patch2 phenomenally looks. One hypothesis is that both patch1 and patch2 phenomenally look red1 to the dog. Another is that both patch1 and patch2 phenomenally look red2 to the dog. The fifth issue I discuss in the thesis concerns what alternative hypotheses there may be regarding how patch1 and patch2 phenomenally look to the dog. Broadly speaking, this thesis is an investigation into the kinds of properties that objects phenomenally look to have. Many philosophers have been interested in questions such as which properties are visible, or which properties visual experience represents. Consider the quotation below from Mackie: ‘If I see someone else peel a potato, I see the relative movement of the potato and the knife, I see the gradually lengthening strip of peel come up from the surface of the potato, each new portion coming up just as the leading edge of the knife reaches it; but, as Hume would rightly protest, I don’t see the knife making the peel come up. And what I most obviously fail to see, though I do judge, is that each bit of the peel would not have come up if the knife had not moved in there.’ (Mackie, 1999, p133). And consider this quotation from Siegel: ‘Consider the content: (#) that Ms. Elfenbein is out of town. ‘This is the sort of content that it would be normal to believe on the basis of perception…But (#) does not seem to be the sort of content that is ever properly attributable to perception itself. Even if one perceived Ms. Elfenbein, despite her absence—perhaps by talking to her on the telephone—one still wouldn’t perceive her being out of town. If one cannot sense that someone is out of town, then (#) is not a content properly attributable to perception.’ (Siegel, 2006, p481). And consider this quotation from Dummett: ‘The notion of an observation report is a very loose one… The following conditions appear to be required. First, the making of the observation report must not rest on any extraneous inference (must not represent ‘a conclusion of the witness’), as e.g., in ‘I see that the Smiths forgot to cancel their newspapers’.’ Dummett, 1976, p95). Mackie, Siegel and Dummett are all appealing to an intuitive distinction between visible and non-visible properties. Mackie’s claim that one cannot see the knife making the peel come up, Siegel’s claim that one cannot perceive Mrs Elfenbein being out of town, and Dummett’s claim that one cannot observe that the Smiths forgot to cancel their newspapers all appeal to the intuitive distinction between visible and non-visible properties. One of the aims of this thesis is to argue for a constraint on the visible/non-visible distinction. A property is visible, I argue, iff it is one that an object can phenomenally look to have. Phenomenal looking is defined as the kind of looking that satisfies the following principle: The Phenomenal Character Principle: Necessarily, for all objects, x, y and z, all properties F and G, all times t1 and t2, and all worlds w1 and w2, if x looks F to z at t1 in w1, y does not look F to z at t2 in w2, and y looks G to z at t2 in w2, then there is a visual phenomenal difference between the way that x looks to z at t1 in w1 and the way that y looks to z at t2 in w2. In chapter 1 I will explain the phenomenal character principle in more detail and distinguish phenomenal looking from other kinds of looking. I assume that visual experience can represent a property iff that property is visible, and therefore that visual experience can represent a property iff that property is one that objects can phenomenally look to have. Two points of clarification are in order. The first is that the notion of a visible property suggests that some properties can be seen, in the same way that objects can be seen. However, as I use the expression ‘visible’, a property is visible iff an object can phenomenally look to have it. I do not assume that properties can be seen. The second point of clarification concerns the modality involved in the expressions ‘visible’ and ‘can phenomenally look to have’. I am interested in what properties objects phenomenally look to have in the actual and nearby worlds. I do not consider what properties it is metaphysically possible for objects phenomenally to look to have. One of the issues discussed in this thesis concerns how rich the range of visible properties is. According to views on which the range of visible properties is very rich, the range of visible properties includes moral properties, the property of being in a particular mental state, theological properties, semantic properties, and the property of belonging to a particular natural kind. According to sparse views, the only visible properties are those such as colour, shape, size and position (the ‘rich/sparse’ terminology is from Lee, 2004). I argue for a very sparse view, according to which the only visible properties are colours and positions. Defenders of relatively rich views of the range of visible properties include Susanna Siegel and Christopher Peacocke, and defenders of relatively sparse views of the range of visible properties include Colin McGinn, Alan Millar and Fred Dretske. In this introduction I discuss the views of some historical figures concerning the visible/non-visible distinction. Then I distinguish the debate over the visible/non-visible distinction from certain other debates, such as the debate over whether observation is theoryladen or not. Lastly, I discuss some tests that contemporary philosophers have proposed that are designed to distinguish visible from non-visible properties. 2 History of the Debate In the 2nd Meditation, Descartes writes as follows: ‘But were I then perchance to look out my window and observe men crossing the square, I would ordinarily say I see the men themselves just as I say I see the wax. But what do I see aside from hats and clothes, which could conceal automata? Yet I judge them to be men. Thus what I thought I had seen with my eyes, I actually grasped with the faculty of judgement, which is in my mind.’ (Descartes, 1993, p22). On the most natural interpretation of this passage, Descartes is investigating which of the properties of the men in the square before him are available to vision, and which are available only to judgement. The conclusion is that whilst he initially thought that the property of being a man was one that ‘I thought I had seen with my eyes’, in fact it is one that ‘I actually grasped with the faculty of judgement.’ According to this interpretation, the implication of the question ‘But what do I see aside from hats and clothes, which could conceal automata?’ is that it is consistent with what Descartes sees to be the case that the objects in the square are automata, and therefore that the property of being a man is not one that, on this occasion, Descartes sees to be instantiated. There was considerable interest in the 18th and 19th centuries concerning whether depth properties are visible; that is, whether or not an object’s distance away from one is a visible property of it. In A New Theory of Vision, Berkeley argued that depth is not visible. ‘It is, I think, agreed by all that distance, of itself and immediately, cannot be seen. For distance being a line directed end-wise to the eye, it projects only one point in the fund of the eye, which point remains invariably the same, whether the distance be longer or shorter.’ (Berkeley, 1975, p9). In Of the Principles of Human Knowledge, Berkeley describes his conclusions from A New Theory of Vision as follows: ‘… in strict truth the ideas of sight…, do not suggest or mark out to us things actually existing at a distance, but only admonish us that ideas of touch will be imprinted in our minds at such and such distances of time, and in consequence of such and such actions.’ (Berkeley, 1975, p89). John Stuart Mill endorsed Berkeley’s argument that depth is not visible, holding that it ‘proves conclusively that distance from the eye is not seen, but inferred’ (Mill, 1875, p95, cited in Smith, 2000, p488). Hume also agreed with Berkeley about depth being non-visible: ‘Tis commonly allowed by philosophers that all bodies which discover themselves to the eye, appear as if painted on a plain surface, and that their different degrees of remoteness from ourselves are discover’d more by reason than by the senses.’ (Hume, 1978 p56, cited in Smith, 2000, p481). Hume also denied that we can observe necessary connections between objects. ‘…we are led astray by a false philosophy… when we transfer the determination of the thought to external objects, and suppose any real intelligible connection betwixt them… [I] have observed, that objects bear to each other the relations of contiguity and succession… But if we go any further, and ascribe a power or necessary connexion to these objects, this is what we can never observe in them.’ (Hume, 1978, p168-9). Reid also held that depth was not visible, and used this premise to argue that the geometry of the shape properties that objects look to have is non-Euclidean. He gives his argument that depth is not visible in the following paragraph: ‘Supposing the eye placed in the centre of a sphere, every great circle of the sphere will have the same appearance to the eye as if it was a straight line. For the curvature of the circle being turned directly toward the eye, is not perceived by it. And for the same reason, any line which is drawn in the plane of a great circle of the sphere, whether it be in reality straight or curve, will appear straight to the eye.’ (Reid, 2000, p103). Reid shows that it follows from this that any plane triangle, that is, a triangle drawn on a plane, will look the same as some spherical triangle, that is, a triangle drawn on the surface of a sphere. He appears to argue that it follows from this point that a plane triangle looks spherically triangular. ‘Hence it is evident, that every visible right-lined triangle, will coincide in all its parts with some spherical triangle. The sides of the one will appear equal to the sides of the other, and the angles of the one to the angles of the other, each to each; and therefore the whole of the one triangle will appear equal to the whole of the other. In a word, to the eye they will be one and the same, and have the same mathematical properties. The properties therefore of visible right-lined triangles, are not the same with the properties of plain triangles, but are the same with those of spherical triangles.’ (Reid, 2000, p104). On a natural interpretation of this paragraph, the argument seems to be that since plane and spherical triangles look the same, they both look spherically triangular. If this is the correct interpretation of the argument, then the argument is invalid, since plane and spherical triangles looking the same is consistent with them both looking to have the property of being a plane triangle. Van Cleve has argued that in fact Reid’s conclusion that both triangles look spherically triangular rests on more than the claim that they look the same (Van Cleve 2002). In the Second Analogy Kant aims to establish the claim that every event has a cause. Kant’s argument has been interpreted in different ways, but at least one interpretation links Kant’s discussion with the visible/non-visible distinction. Guyer writes as follows: ‘In the Second Analogy, Kant argues for a further condition for making judgments about change in objects: because even when we undergo a sequence of perceptions, there is nothing in their immediate sensory content to tell us that there is an objective change, let alone what particular sequence of change there is, we can only distinguish a ‘subjective sequence of apprehension from the objective sequence of appearances’ (A 193/B 238) by judging that a particular sequence of objective states of affairs, a fortiori the sequence of our perceptions of those states, has been determined in accordance with a rule that states of the second type can only follow states of the first type - precisely what we mean by a causal law.’ (Guyer, 2004, §7). If Guyer is right, then the Second Analogy raises the question whether there are perceptions of change, or merely changes in one’s perceptions. This is equivalent to the question whether the property of having changed is a visible property. According to Guyer’s interpretation of the Second Analogy, it is a premise of the Second Analogy that there are no perceptions of change, but instead only changes in one’s perceptions. 3 What The Issue Is Not 3.1 The Observation/Theory Distinction Putnam introduces the observation/theory distinction as follows: ‘The basis for the division appears to be as follows: the observation terms apply to what may be called publicly observable things and signify observable qualities of these things, while the theoretical terms correspond to the remaining unobservable qualities and things.’ (Putnam, 1962, p240). Thus, for Putnam, the observation/theory distinction is at least the distinction between observable and unobservable properties. Putnam also claims that it is a distinction between observable and unobservable things, but I will not focus on this latter distinction. At one point in ‘Observation Reconsidered’, Fodor seems to agree that the distinction between observable and non-observable properties is the central distinction in the observation/theory debate: ‘The obvious suggestion would be, on the one hand, that what makes a term observational is that it denotes, by independent criteria, an observable property.’ (Fodor, 1983, p30). However, at the beginning of ‘Observation Reconsidered’, Fodor characterizes his project as follows: ‘Several arguments are considered which purport to demonstrate the impossibility of theory-neutral observation. The most important of these infers the continuity of observation with theory from the presumed continuity of perception with cognition, a doctrine widely espoused in recent cognitive psychology.’ (Fodor, 1984, p23). Theory-neutral observation is defined by Fodor as follows: ‘As a first shot at what the theory-neutrality of observation comes to: given the same stimulations, two organisms with the same sensory/perceptual psychology will quite generally observe the same things, and hence arrive at the same observational beliefs, however much their theoretical commitments may differ.’ (Fodor, 1984, p25). It seems that there are two issues in the debate over the observation/theory distinction. One is whether a distinction between observable properties and non-observable properties can be drawn, and the second is whether there is theory-neutral observation. In Fodor’s paper these two issues are run together; the argument in the paper suggests that Fodor thinks that there is a distinction between observable and non-observable properties only if there is theory-neutral observation. I will argue that this is incorrect, and that there may still be a distinction between observable and non-observable properties even if all observation is theory-laden. Let us suppose that, if a particular observation can be laden with a theory about Fs, then being F is an observable property. This assumption fits with how philosophers have used the notion of theory-laden observation: if one’s observation is laden with a theory one has about gamma-ray tubes, then the property of being a gamma-ray tube can be observed. Suppose that observation can be laden by any theory. This supposition would entail that all properties are observable. It would not undermine the notion of an observable property, nor would it undermine the notion that there is a distinction between observable properties and unobservable properties. It would show simply that there are no properties on one side of this distinction. Consider an analogy with desire. Let us suppose that, if one’s desires can be laden with a theory about Fs, then the property of being F can feature in the content of one’s desires. Suppose that one’s desires can be laden with any theory. This supposition would entail that any property could feature in the contents of one’s desires. It would not undermine the notion of a property that can feature in the content of one’s desires, nor would it undermine the distinction between properties that can feature in the contents of desires and those that cannot. The following is one way in which one might try to defend the claim that if observation is theory-laden, then there is no distinction between observable and unobservable properties. The claim that observation is theory-laden is often accompanied by the claim that vision is continuous with judgement. Suppose that there are simply judgements, some of which are more observational than others. One might think that if this is the case, then there is no difference between observable and unobservable properties. However, this would be a mistake. The fact that some judgements are more observational than others does not mean that no judgements are observational, simpliciter. Analogously, the fact that some cars are faster than other cars does not mean that no cars are fast, simpliciter. It is incorrect to suppose that whenever there is a continuum of Fness, there is no distinction between being F and not being F. On this view, the observable properties would be the ones that can feature in the observational judgements. If there are simply judgements, some of which are more observational than others, then it may be conceded that, in some sense, there is no qualitative difference between observable properties and unobservable properties, just as, in some sense, there is no qualitative distinction between fast and slow cars. One might think that if there is no qualitative distinction between observable and unobservable properties, and therefore that observability is a matter of degree, then there would be less interest in the notion. However, there does not seem to be any reason why this would be the case. The fact that justification and goodness come in degrees does not make them any philosophically less interesting notions. There is a question about whether philosophers writing about the observation/theory distinction were really interested in whether observation was theory-laden, or whether they were really interested in whether a distinction can be drawn between observable properties and unobservable properties. At least part of the interest in the observation/theory distinction was epistemological. Fodor writes: ‘Second, the observational fixation of belief plays a special role in the adjudication and resolution of clashes of opinion. When observation is not appealed to, attempts to settle disputes often take the form of a search for premises that the disputants share… None of this applies, however, when the beliefs at issue are observational. Since observation is not a process in which new beliefs are inferred from old ones, the use of observation to resolve disputes does not depend on a prior consensus as to what premises may be assumed.’ (Fodor, 1984, p24). Fodor’s argument is that if observation is theory-neutral, then it can provide evidence for or against a theory. By contrast, if observation is theory-laden, it is less clear that it can be provide evidence for or against a theory. This suggests that the real interest in the debate over the observation/theory distinction is in whether observation is theory-laden, rather than in whether there is a distinction between observable and unobservable properties. In this section I have argued that the issue of whether there is an observable/unobservable distinction is independent of the issue of whether observation is theory-laden. However, there may well be a connection between the question whether observation is theory-laden and the question what range of properties is observable. For instance, many philosophers who argue for a rich view about the range of visible properties hold that observation is theory-laden, and that observation can be laden with a rich range of theories. I will discuss these views in more detail below. 3.2 Conceptual/Nonconceptual Content A state is conceptual iff a subject’s being in that state entails that that subject possesses concepts that characterize the content of that state. A state is nonconceptual iff it is not conceptual. For this definition of conceptual content, see Cussins 1992, Brewer 1999, Evans 1982. The question whether there is a distinction between visible and non-visible properties is independent of the question whether visual experience is a conceptual state. One may hold that visual experience is a conceptual state and also think that there is a distinction between properties that are represented by visual experience and properties that are not. 3.3 The Given In ‘Empiricism and the Philosophy of Mind’, Wilfrid Sellars launched an attack on the ‘myth of the given’ (Sellars 1997). Some commentators have argued that Sellars is not entirely clear about what the myth of the given is. Daniel Bonevac writes as follows: ‘Sellars never specifies precisely what the Myth of the Given is. Tracing Sellars’s dialectic, the reader gets the sense that the target repeatedly shifts. The thesis that there is something independent of acquired conceptual capacities given in experience remains entangled with the role the thesis plays in foundationalist theories of knowledge.’ (Bonevac, 2002, p1). McDowell takes Sellars to be interested in the question whether perceptual experience has nonconceptual content: ‘My thinking starts from a central element in Wilfrid Sellars’s attack on the Myth of the Given. Sellars means to undermine more than traditional empiricism. But in his classic ‘Empiricism and the Philosophy of Mind’ he concentrates on the idea of something given in experience independently of acquired conceptual capacities.’ (McDowell, 1998a, p365). If McDowell’s interpretation is correct, then whether there is a given or not is a separate question from whether there is a distinction between visible and non-visible properties. 3.4 Inferential vs. Immediate Belief It is tempting to think of the distinction between visible properties and non-visible properties in terms of the distinction between properties that one immediately forms beliefs about, and properties which one forms beliefs about only inferentially. Consider the following dialogue: Jody: I work on the distinction between visible and non-visible properties. Derek: Oh, what is that all about? Jody: Well, suppose that you are looking at wet pavements, and you judge that it has just rained. Is it literally part of what you see that it has just rained? Derek: No, clearly I infer that it has just rained on the basis of my visual experience and some background beliefs about the most likely cause of the pavements being wet. On the other hand, I directly, non-inferentially believe that the pavements are wet, so presumably that the pavements are wet is part of what I see. Derek’s last reply to Jody is a very natural one to make. However, the visible/non-visible distinction is not the same as the distinction between properties that one can form beliefs about non-inferentially and properties that one can form beliefs about only inferentially. Firstly, it may be that when one forms a belief, about some object, that it is red, this belief is inferred from the belief that the object looks red, and that things are the way they look. In addition, one’s belief that the object looks red may be an inference from the belief that it does not look green, the belief that it does not look blue, and so on. Whether these inferences occur or not is independent of whether being red is a visible property. Secondly, a subject could be wired to believe, whenever they see wet pavements, that it has just rained. When such a subject sees wet pavements, the belief about its having just rained that would be formed would be non-inferential. However, this would not show that the property of its having just rained would be visible by this subject. 3.5 What is Seen vs. What is Believed One might think that the distinction between visible and non-visible properties is the same as the distinction between properties that one can see and properties that one can only have mental states such as beliefs and desires about. Thus, for instance, colour properties can be seen, but perhaps the property of having forgotten to cancel the papers is one that one can have only mental states such as beliefs and desires about. However, for all that has been said, visual experience may be a kind of belief. If visual experience was a certain kind of belief, there would still be a distinction between visible and non-visible properties, namely a distinction between properties that can feature in the contents of this kind of belief and properties that cannot. The existence of a distinction between visible and non-visible properties is independent of the question whether visual experience is a kind of belief state. 3.6 The Sense-Datum Theory of Perception Occasionally, in conversation, philosophers have wondered whether defenders of the sparse view, who hold that the range of visible properties includes only properties such as colour and shape, are defending a version of the sense-datum view of perception. The sense-datum view is a certain view about the metaphysics of the perceptual relation. It holds that visual perception consists in the subject’s being aware of internal mental images that are caused in the right way by external objects. A defender of the sparse view of visible properties is not committed to any particular view of the metaphysics of the perceptual relation. One can think that objects phenomenally look to have only a restricted range of properties and be neutral on which account of the metaphysics of the perceptual relation is correct. 4 Similar Problems In Other Areas of Philosophy 4.1 Visual Imagination There is a question about what properties one’s visual imagination can represent. Call the imaginability thesis the claim that, for any proposition p, being able visually to imagine that p entails that it is possible that p. Suppose that one can visually imagine that water is not H2O. If this was possible, then the imaginability thesis would be false, since necessarily, water is H2O. However, one might argue that one cannot imagine that water is not H2O, despite it seeming as though one can. According to this argument, one really imagines that a transparent liquid that falls from the sky and fills the lakes is not called ‘H2O’ by scientists, and one misdescribes the content of one’s visual imagination as being that water is not H2O. If the content of one’s visual imagination is that a transparent liquid that falls from the sky and fills the lakes is not called ‘H2O’ by scientists, then the imaginability thesis remains intact, since it is possible that a transparent liquid that falls from the sky and fills the lakes is not called ‘H2O’ by scientists. Thus, what range of properties one can visually imagine makes a difference to arguments about whether the imaginability thesis is true. Wittgenstein was also interested in the question as to what properties visual imagination represents. Here he asks whether visual imagination can represent the property of being King’s College, or whether it can represent only properties such as being a building. ‘Someone says, he imagines King’s College on fire. We ask him: “How do you know that it’s King’s College you imagine on fire? Couldn’t it be a different building, very much like it? In fact, is your imagination so absolutely exact that there might not be a dozen buildings whose representation your image could be?”—And still you say: “There’s no doubt I imagine King’s College and no other building.”’ (Wittgenstein, 1958, p39). 4.2 Aesthetics Kendall Walton argues that what distinguishes the way a picture represents a mill, say, from the way a novel represents a mill is that, when looking at a picture, one imagines that the object of one’s visual perception is the mill, whereas when looking at a verbal description of a mill, one does not imagine that the object of one’s visual perception is the mill. (Walton, 1990). Walton says that a depiction is a prop used in the activity of imagining that the object of one’s perception is something other than the actual object of one’s perception. When one looks at a depiction of a mill, Walton says that one fictionally sees the mill. Walton discusses what restrictions there may be on the properties that can be depicted: ‘Pictures—representations that are depictive in some respects—can portray (generate fictional truths about) non-visual phenomena, of course. The question is whether this portrayal is depiction. The indirect representation of the sound of a shot by means of the sudden rising of a flock of birds in The Docks of New York is clearly not depiction. Seeing the images of the rising birds is not, fictionally, perceiving the shot. What about the portrayal in cartoons of sounds and patterns of thermal radiation or smells by means of concentric arcs or wavy lines emanating from the source—a gong or a campfire or a garbage heap? It is probably not fictional that we see sounds or smells or heat when we see the picture, nor is our looking at the picture fictionally a looking at such non-visual phenomena.’ (Walton, 1990, p331-2). Given Walton’s definition of a depiction, the range of possible contents of a depiction is constrained by what one can imagine to be the object of one one’s visual perception. If it is not possible to imagine that one is visually perceiving a sound, then no representation can depict a sound. Even if one disagrees with Walton’s theory of depiction, one may still ask whether the way in which a picture can represent a sound or a smell is the same as the way in which a picture can represent a colour or a shape. 4.3 Semantics/Pragmatics Suppose that Tom says ‘I have not had a bath’. Certainly, in making this utterance, Tom implies that he has not had a bath today. However, there is a question about whether Tom’s utterance expresses the proposition that he has not had a bath today, or whether it expresses the proposition that has not had a bath, which entails that Tom has never had a bath. The question concerns where to draw the line between the semantic content of an utterance and what is pragmatically implied by the utterance. Suppose that a sales assistant in the supermarket says ‘all the chocolate has sold out’. Certainly, in making this utterance, the sales assistant implies that all the chocolate in the supermarket has sold out. However, there is a question about whether the sales assistant’s utterance expresses the proposition that all the chocolate in the supermarket has sold out, or whether it expresses the proposition that all the chocolate in the universe has sold out. An utterance expresses a certain semantic content. Someone who hears that utterance will acquire a bundle of information on the basis of hearing it. There is a question about how much of the bundle of information is part of the semantic content expressed by the sentence and how much is due to other factors. The analogy with the visible/non-visible distinction is as follows. A visual experience has a certain content. Someone who has that visual experience will acquire a bundle of information on the basis of having it. There is a question about how much of the bundle of information is part of the content of the visual experience, and how much is due to other factors. One test for distinguishing semantic content from pragmatic content is as follows. If there are two utterances, u1 and u2, which express the same proposition, and there is some proposition q that is conveyed by u1 that is not conveyed by u2, then q is not part of the semantic content of u1 or u2. The analogue of this test for the visible/non-visible distinction is as follows. If there are two objects, O1 and O2, which phenomenally look the same, and for some property F, O2 does not phenomenally look F, then O1 does not phenomenally look F either. Suppose that an object x phenomenally looks red and round, and there is disagreement about whether x phenomenally looks to be a tomato. If there is an object y that phenomenally looks the same as x, but does not phenomenally look to be a tomato, then x does not phenomenally look to be a tomato. I will be using a different test in chapter 1, but this test and my test raise some of the same issues. 5 The Debate in Contemporary Philosophy 5.1 Epistemological motivations The following is the structure of one traditional kind of sceptical argument: 1.) Experience does not represent properties of kind F. 2.) If experience does not represent properties of kind F, then experience does not justify our beliefs about properties of kind F. 3.) If experience does not justify our beliefs about properties of kind F, then nothing justifies our beliefs about properties of kind F. 4.) Therefore, our beliefs about properties of kind F are not justified. This argument has been applied to a number of different kinds of property, including the mental properties of others, properties of objects that are too small to see, moral properties, semantic properties and theological properties. A common response to this kind of argument has been to deny 1.), and argue that experience does represent properties of the kind in question. 5.1.1 Other Minds McDowell’s response to the problem of other minds is as follows. ‘In the view of this different realist, we should not jib at, or interpret away, the common-sense thought that, on those occasions that are paradigmatically suitable for training in the assertoric use of the relevant part of a language, one can literally perceive, in another person’s facial expression or his behaviour, that he is in pain, and not just infer that he is in pain from what one perceives.’ (McDowell, 1998b, p305). It seems that in this passage, McDowell is arguing that one’s perceptual experiences can represent that someone is in pain. In an earlier work, McDowell and Evans write: ‘Seeing cheerfulness in a face is not inferring that its owner is cheerful from the way his face looks.’ (Evans and McDowell, 1976, pxxii). In her paper ‘Perceiving Intentions’, Joelle Proust argues that one’s experiences can represent the mental properties of others. ‘It is a fact of experience that when a perceiver observes someone else’s bodily movements, she directly perceives these movements as goal-directed and intentional.’ (Proust, 2003, p6). Peacocke also argues that the property of being sad is visible: ‘To describe, when seeing the face of a person, the experience in which they look sad in non-emotional terms is not to capture its distinctive representational content. There is no kind, described without reference to the emotions, of which one can say that the facial expression appears to be of that kind, and it is merely an additional judgment on the part of the person that people looking that way are sad.’ (Peacocke 2003, p66). 5.1.2 Moral Properties In Moral Vision, David McNaughton argues that moral beliefs are justified by our experiences representing moral properties. He writes: ‘I do not see an expanse of coloured cloud, which is not itself seen as beautiful, and then experience a thrill of pleasure to which I give the name of beauty. The beauty of the sunset is woven into the fabric of my experience of it. I see the sunset as beautiful… ‘Reflection on the aesthetic case can serve to make us less certain of Hume’s claim in the moral case. If I see several children throwing stones at an injured animal I may claim that I can just see that what they are doing is cruel. Similarly, the insolence of a drunken guest’s behaviour seems no less observable than the cut of his suit.’ (McNaughton, 1988, p56). 5.1.3 Properties of Objects-Too-Small-To-See A sceptical argument of the above kind has been applied to properties such as electrons. How can our beliefs about electrons be justified if our experience does not represent anything as an electron? Consider the following passage from Robert Brandom. ‘It is important to understand that under the appropriate circumstances, which include the presence of a bubble chamber or similar device, and for the right community of observers, mu-mesons are literally observable—noninferentially reportable in the same sense in which red things are for the rest of us. It is a mistake to think that what is really non-inferentially observed is only the vapour trail and that the presence of mu-mesons is only inferred.’ (Brandom, 1994, 223). Brandom seems to be arguing in this passage that the property of being a mu-meson is observable because mu-mesons are non-inferentially reportable. 5.1.4 Theological Properties A sceptical question arises about the epistemological status of religious belief. William Alston has argued that religious beliefs can be justified by perceptual experiences which represent theological properties. He writes: ‘The central thesis of this book is that experiential awareness of God, or as I shall be saying, the perception of God, makes an important contribution to the grounds of religious belief. More specifically, a person can become justified in holding certain kinds of beliefs about God by virtue of perceiving God as being or doing so-and-so. The kinds of beliefs that can be so justified I shall call ‘Mbeliefs’ (‘M’ for ‘manifestation’). M-beliefs are beliefs to the effect that God is doing something currently vis-à-vis the subject—comforting, strengthening, guiding, communicating a message, sustaining the subject in being—or to the effect that God has some (allegedly) perceivable property—goodness, power, lovingness.’ (Alston, 1991, p1). In ‘The Myth of Religious Experience’, Nick Zangwill argues, against Alston, that it is not possible for perceptual experiences to represent theological properties (Zangwill, 2004). 5.1.5 Semantic Properties Gareth Evans and John McDowell raise the question how one comes to know what someone means by an utterance. In a passage partly quoted above, they claim that one can perceive the meaning in someone’s utterance: ‘Seeing cheerfulness in a face is not inferring that its owner is cheerful from the way his face looks…. Just so, we suspect, with language: that is, it is essential to language as we know it that our understanding of meanings should normally be perception of meaning, and hence precisely not a matter of inference. (Evans and McDowell, 1976, pxxii). 5.2 Non-epistemological motivations Not all philosophers are interested in the visible/non-visible distinction for epistemological reasons. As we saw at the beginning of this introduction, Mackie claims that causation is not visible: ‘If I see someone else peel a potato, I see the relative movement of the potato and the knife… but… I don’t see the knife making the peel come up.’ (Mackie, 1999, p133). Strawson argues: ‘[T]here are countless true specifications or descriptions of the things we, for example, see… which do not, and perhaps could not, figure in any truthful account of, for example, how those things look to us. Examples would be the descriptions ‘married five times’, as applied to a man, or ‘once shaken by the Queen’, as applied to a hand.’ (Strawson, 1974b, p67) Burge claims that the visual system can detect a sparse range of properties: ‘There is considerable empirical evidence that perceptual systems per se make reference to properties within a relatively confined range. The human visual system makes reference to particular colours, shapes, positions, motions, textures—and to certain abstractions from them—as such, but not to tomatoes, mercury, cancer, cars, presidents, sonnets, as such.’ (Burge, 2003, pp545-546). Pollock claims that an object does not visually look to have a back of one kind rather than another: [C]onsider the easiest case, which is the case in which it turns out that the wall is all that is left of an old church— there is nothing behind it. When we take ourselves to be seeing a church we are making a mistake, but it is not a perceptual error…. The information encoded by perception is not wrong — it is the judgment we make on the basis of it that is wrong.’ (Pollock, forthcoming, p18). Colin McGinn argues for a sparse view in the following paragraph: ‘[Since] it is possible for things to have the same appearance as tigers, yet not fall under the concept of tiger, we should therefore restrict the concepts invoked to characterize content to those that relate to the appearances of things: concepts of colour, superficial texture, shape etc. In this way we limit our ascription of content to how things seem to the perceiver.’ (McGinn, 1982, p40). In the following passage David Smith picks up on the distinction between perception of change and change of perception that is salient in Kant’s argument in the 2nd Analogy: ‘The crucial point to recognize in all this is that a succession of appearances does not of itself amount to the appearance of succession… just as a changing appearance does not entail an appearance of change, a persisting appearance does not entail an appearance of persistence.’ (Smith, 2002, p124). The question whether depth is visible is still discussed. Price claimed that depth is visible: ‘It is obvious that all visual sense-data have the characteristic of depth, or ‘outness’. This characteristic is just as much given as colour or shape, whether we can explain it or not.’ (Price, 1950, p218). O’Shaughnessy has endorsed Berkeley’s argument that depth is not visible (O’Shaughnessy 1980 vol.1 p172, cited in Smith, 2000). Smith considers a number of arguments for the view that depth is not visible and finds them wanting (Smith 2000). In The Bounds of Sense, Strawson discusses the geometry of the shapes that objects look to have. He defines phenomenal geometry as the geometry of the figures that we represent in visual imagination, and states that ‘if there is such a thing as phenomenal geometry, then we could reasonably say that it would primarily be the geometry of the spatial appearances of physical things and only secondarily, if at all, the geometry of physical things themselves.’ (Strawson, 1966, p282). Strawson argues that phenomenal geometry is Euclidean: ‘Consider the proposition that not more than one straight line can be drawn between any two points. The natural way to satisfy ourselves of the truth of this axiom of phenomenal geometry is to consider an actual or imagined figure. When we do this, it becomes evident that we cannot, either in imagination or on paper, give ourselves a picture such that we are prepared to say of it both that it shows two distinct straight lines and that it shows both these lines as drawn through the same two points.’ (Strawson, 1966, p283). Hopkins has argued in response to Strawson that for small objects of the kind we see, a Euclidean triangle would look the same as a non-Euclidean triangle, and that phenomenal geometry is neutral or indeterminate between being Euclidean and being non-Euclidean (Hopkins, 1973, p22-23). Many philosophers have argued that the geometry of the shape properties that objects look to have is non-Euclidean. Van Cleve (2002), Yaffe (2002) and Belot (2003) have defended updated versions of Reid’s argument for this view, and Angell (1974) and Lucas (1969) have offered their own arguments for this view. 6 Tests For The Visible/Non-Visible Distinction We need a test in order to decide which properties are visible and which are non-visible. We cannot take true sentences containing perceptual verbs at face-value, since we often use perceptual verbs to refer to non-perceptual states. For instance, consider the following dialogue which, we may suppose, takes place in the dark: Martha: Susan: It looks to me as if you are in agreement with Russell. I see what you mean. Both sentences uttered in this dialogue contain perceptual verbs, and yet Martha and Susan are not referring to perceptual states. One might argue that Martha and Susan are using the perceptual verbs metaphorically, but then a test would be needed to distinguish metaphorical from non-metaphorical uses of perceptual verbs. I shall now consider some tests to distinguish visible from non-visible properties. 6.1 The Ascent Routine Test When discussing how a subject can gain knowledge of the contents of his perceptual experiences, Evans writes as follows: ‘[A] subject can gain knowledge of his internal informational states in a very simple way: by re-using precisely those skills of conceptualization that he uses to make judgements about the world. Here is how he can do it. He goes through exactly the same procedure as he would go through if he were trying to make a judgement about how it is at this place now, but excluding any knowledge he has of an extraneous kind. (That is, he seeks to determine what he would judge if he did not have such extraneous information.). The result will necessarily be closely correlated with the content of the informational state which he is in at that time. Now he may prefix this result with the operator ‘It seems to me as though…’ (Evans, 1982, p227-8). In a footnote, Evans writes: ‘For ‘extraneous’, see Dummett, ‘What is a Theory of Meaning (II)?’, p95. The relevant passage in Dummett has been quoted above, and is reproduced below: ‘The notion of an observation report is a very loose one. Without attempting to go into all the problems which arise if one wishes to make it sharper… the following conditions appear to be required. First, the making of the observation report must not rest on any extraneous inference (must not represent ‘a conclusion of the witness’), as e.g., in ‘I see that the Smiths forgot to cancel their newspapers’.’ Dummett, 1976, p95). The above remarks suggest the following test for determining what properties our visual experiences represent: Ascent Routine Test: Necessarily, for all propositions p and subjects s, if s would judge, ignoring any information extraneous to his visual experience, that p, then s’s visual experience represents that p. Robert Gordon endorses an analogue of the ascent routine test for belief. Later he argues that this test can also allow a subject to gain knowledge of whether they are in pain, so it is possible that he would endorse the ascent routine test itself. Gordon writes: ‘I argue that such self-ascription relies instead on what I call ascent routines. For example, the way in which adults ordinarily determine whether or not they believe that p is simply to ask themselves the question whether or not p. Thus, if someone were to ask me, (Q1) ‘do you believe Mickey Mouse has a tail?’ I would ask myself, (Q2) ‘Does Mickey Mouse have a tail?’ (with certain constraints on how I obtain the answer to Q2). If the answer to Q2 is Yes, then the presumptive answer to Q1 (the best I can do without taking into consideration possible conflict between verbal and non-verbal behaviour) is Yes (or, ‘Yes, I do believe that Mickey Mouse has a tail’). The answer to Q1 is No if either the answer to Q2 is no or no answer is available within the constraints.’ (Gordon, 1996, p15). In the following passage Peacocke employs a stronger version of the ascent routine test which includes both a necessary and a sufficient condition for an experience to have a particular content: ‘We see things as tomatoes, and not as anything weaker. If the representational content of experience is given by what someone would judge, taking that experience at face value, then our ordinary experiences have a content concerning tomatoes, and not tomato-like objects.’ (Peacocke, 1983, p93). Peacocke’s test as follows: Peacocke’s Test: Necessarily, for all propositions p and subjects s, s’s experience represents that p iff s would judge that p, taking his experience at face value. I will assume that the expressions ‘ignoring any information extraneous to his visual experience’ and ‘taking his experience at face value’ specify the same condition. Peacocke’s test differs from the ascent routine test only in that Peacocke holds that it is a necessary condition on one’s experience representing that p that one would judge, taking one’s experience at face value, that p. If perceptual experience has a non-conceptual content, then this necessary condition will have to be rejected. For arguments that experience does have a nonconceptual content, see Evans 1982, Bermudez 1998, Cussins 1990, Heck 2000 and Peacocke 2001. I will focus on the weaker ascent routine test, rather than Peacocke’s test. Evans himself suggests that the ascent routine test is not correct: ‘The procedure I have described does not produce infallible knowledge of the informational state, for mistakes of the kind that occur when the subject makes judgements about the world can also produce inaccuracies when the same procedure is re-used for this different purpose. Consider a case in which a subject sees ten points of light arranged in a circle, but reports that there are eleven points of light arranged in a circle, because he has made a mistake in counting, forgetting where he began. Such a mistake can clearly occur again when the subject re-uses the procedure in order to gain knowledge of his internal state: his report ‘I seem to see eleven points of light arranged in a circle’ is just wrong.’ (Evans, 1982, p229). Evans claims that such mistakes are limited: ‘However, when the subject conceptualizes his experience in terms of some very elementary concept, such as a simple colour concept like ‘red’, it is not easy to make sense of his making a mistake.’ (Evans, ibid, p229). This latter claim seems questionable. One can change one’s mind about the colour an object looks. For instance, consider looking at a rock face which is brown with a purple tinge. Because rock faces with a purple tinge are unusual, one might be particularly struck by the purple tinge of the rock face, and judge, taking one’s experience at face value, that the rock face is purple. On second thoughts, one might realize that the rock face is not purple, but merely brown with a purple tinge. It seems quite possible that one’s visual experience stays the same whilst one changes one’s mind about the colour of the rock face. This point echoes Tim Williamson’s point that a hypochondriac may judge falsely of an itch that it is a pain (Williamson, 2000, p24). A second criticism concerns the condition of ‘taking one’s experience at face value’, or ‘ignoring information extraneous to the experience’. On one understanding, ‘taking one’s experiences at face value’ means ignoring any collateral information or background beliefs that one has. However, this condition seems too strong. Suppose that an object looks red, and that one seeks to determine what one would judge on the basis of one’s visual experience, ignoring all of one’s background beliefs, including such beliefs as one’s belief that red objects look like that, the belief that there are many shades of red, and the belief that objects are the way they look. In such a situation it does not seem that one would form any judgement. Similarly, if an object looks square, and one seeks to determine what one would judge, ignoring all of one’s background beliefs, including such beliefs as the belief that squares have four sides, then it does not seem that one would form any judgement. On a second understanding of ‘taking one’s experiences at face value’ and ‘ignoring information extraneous to the experience’, these expressions mean ‘assuming that all and only the properties represented by the experience are instantiated’. However, on this understanding, to apply the ascent routine test is circular; one can apply it only if one first knows what properties are represented by one’s experience. Thus it seems that the conditions of taking one’s experiences at face value and ignoring information extraneous to the visual experience are either circular, or are so strong that they would rule out any property from being represented by one’s experiences. 6.2 Lewis’s Test In the following passage, Lewis proposes a test for determining the content of experience: ‘Visual experience depends on the scene before the eyes, and the subject’s beliefs about that scene depend in turn partly on his visual experience. The content of the experience is, roughly, the content of the belief it tends to produce. ‘The matter is more complicated, however. The same visual experience will have a different impact on the beliefs of different subjects, depending on what they believed beforehand. (And on other differences between them, e.g. differences of intelligence.) Holmes will believe more on the basis of a given visual experience than Watson; and Watson in turn will believe more than someone who suspects that he has fallen victim to a field linguist no less powerful than deceitful. We should take the range of prior states that actually exist among us, and ask what is common to the impact of a given visual experience on all these states. Only if a certain belief would be produced in almost every case may we take its content as part of the content of the visual experience. (The more stringently we take ‘almost every’, the more we cut down the content of the visual experience and the more of its impact we attribute to unconscious inference; for our purposes, we need not consider how that line ought to be drawn.) ‘… Not all the content of visual experience can be characterized in terms of the beliefs it tends to produce. It is part of the content that the duck-rabbit look like a duck or a rabbit, but the belief produced is that there is no duck and no rabbit but only paper and ink’ (Lewis, 1980, p239-240). Let us formulate Lewis’s test as follows: Lewis’s Test: Necessarily, for all propositions p, and experiences e, if e would produce the belief that p in almost every case, then e represents that p. The above test provides a sufficient condition for an experience to represent a proposition. It is not clear whether Lewis also intended his test to provide a necessary condition for experience to represent a proposition. He writes above ‘Only if a certain belief would be produced in almost every case may we take its content as part of the content of the visual experience.’ This suggests that the test is intended to provide a necessary condition on an experience representing a property. However, at the start of the final paragraph quoted above, he writes ‘Not all the content of visual experience can be characterized in terms of the beliefs it tends to produce’. This suggests that the test is not intended to provide a necessary condition on visual experience representing a proposition. In what follows I will assume that Lewis intends to provide only a sufficient condition for experience to represent some proposition p. One problem with the ascent routine test that Evans pointed out is that subjects are not infallible about how things look to them. Certain judgements that subjects make, taking their experiences at face value, will not reflect the contents of those experiences. It seems that Lewis’s test faces this problem also, since it seems as conceivable that everyone may make a mistake about a particular experience as it is that one person may make a mistake about a particular experience. For instance, consider Evans’s example of someone who miscounts the number of lights before them, and judges that there are eleven lights in a circle when in fact there are ten. Suppose that everyone makes this mistake. It still seems that in this case everyone’s experiences represent ten lights, not eleven. Lewis’s test would entail that their experiences represented eleven lights. Similarly, suppose that, when looking at the rock face described above, everyone was struck by its purple tinge and judged, taking their experiences at face value, that the rock face was purple, and then changed their minds and decided that it was brown with a purple tinge. It seems that everyone may change their mind about the colour of the rock face without their visual experiences changing. Lewis’s test assumes that errors such as these will be local and not widespread. Whilst he is right that it is less likely that everyone will make a mistake than that one person will make a mistake, it still seems conceivable that everyone will make a mistake. A second problem concerns the use of extraneous information. When forming judgements on the basis of their experiences, subjects may rely on background information as well as the information that their experiences represent in order to form their judgement, with the effect that the judgement goes beyond the content of the experience. The ascent routine explicitly rules out the use of such extraneous information. Lewis’s test does not. It seems that Lewis’s appeal to what beliefs an experience would produce in almost every case is an attempt to isolate those beliefs that do not rest on information extraneous to the experience. The thought may be the following. Suppose that a subject S forms a belief B, partly on the basis of an experience E, and partly on the basis of information I which is extraneous to E. The suggestion may be that it is unlikely that almost everyone has I, and therefore unlikely that E will produce B in almost every case. However, it seems conceivable that everyone has I. Consider Dummett’s example above of a judgement that is based on an experience and also on information extraneous to the experience: ‘I see that the Smiths forgot to cancel their newspapers’. Let us assume that the subject in Dummett’s case sees a pile of newspapers outside the Smiths’ house, and when forming the judgement that the Smiths forgot to cancel their newspapers, relies on the information, extraneous to the experience, that a pile of newspapers outside someone’s house is a reliable indication of the inhabitants of the house having forgotten to cancel their newspapers. It seems quite possible that everyone has this extraneous piece of information. Perhaps there are no cultures in which people do not believe that a pile of newspapers outside someone’s house reliably indicates that the inhabitants of the house have forgotten to cancel their newspapers, and perhaps this is also the case in nearby worlds. If this is the case, the experience of newspapers piling up in front of someone’s house will produce in almost everyone the belief that the inhabitants of the house have forgotten to cancel their newspapers. Thus Lewis’s condition that an experience produce the same belief in almost every case does not succeed in isolating those beliefs that are based only on an experience, and not on information extraneous to the experience. A third problem with Lewis’s test is that it entails that the contents of say, F-type experiences in a subject S are dependent on what beliefs F-type experiences produce in others, which is a counter-intuitive result. Take any proposition which, at t1, F-type experiences do not represent. Suppose that, at t2, F-type experiences produce the belief that p in almost every case. Lewis’s test entails that, at t2, F-type experiences represent that p. Lewis’s test allows for the following possibility: that S’s F-type experiences change from not representing p to representing p entirely because of cognitive changes in others. This situation could occur either if S’s F-type experiences produce the belief that p at both t1 and t2, or if S’s F-type experiences produce the belief that p at neither t1 nor t2. That this is a possibility seems to be a counter-intuitive consequence of Lewis’s test. A fourth problem with Lewis’s test concerns sole inhabitants of worlds. Suppose that S is the only subject in the world, and suppose that S is very persuasive, so that, were anyone else to exist, S would persuade them to believe the same propositions on the basis of their experiences as she does on the basis of hers. Lewis’s test has the consequence that, for any proposition p such that an F-type experience in S produces the belief that p, an F-type experience of S represents that p. This seems a counter-intuitive result. 6.3 The Same Look Test Alan Millar, Fred Dretske and Colin McGinn propose a test for distinguishing visible properties from non-visible properties in the following passages: ‘[I]f there is a possible situation in which it is false that A is G, yet everything (including A), looks the same as in the actual situation [in which A is G], then clearly the fact that A is G is not a fact merely about the look of A.’ (Millar, 2000, p4). ‘If you can get a B (e.g., fool's gold) that looks (in the phenomenal sense-assuming there is such a sense) the same as A (gold), then experience does not represent something as A (or B).’ (Dretske, correspondence). ‘[Since] it is possible for things to have the same appearance as tigers, yet not fall under the concept of tiger, we should therefore restrict the concepts invoked to characterize content to those that relate to the appearances of things: concepts of colour, superficial texture, shape etc. In this way we limit our ascription of content to how things seem to the perceiver.’ (McGinn, 1982, p40). We can formulate the test that Millar, Dretske and McGinn propose as follows. The Same Look Test: Necessarily, for all properties F, if there is an object that is F that looks the same as an object which is not F, then being F is not a visible property. The same look test is stronger than some of its proponents have noticed. No properties that are standardly thought of as visible pass the same look test. Consider the properties of being square and being triangular. Suppose that one sees a square in normal lighting conditions, and a triangle placed under a prism in such a way it looks square. In this example a square looks the same as an object which is not square, and therefore, according to the same look test, being square is not a visible property. A similar style of argument would entail that colour properties and position properties are non-visible. The problem with the same look test is that, if an object that is F looks the same as an object which is not F, this is consistent with them both looking F. Therefore, the fact that gold looks the same as fool’s gold does not entail that being gold is a non-visible property; it may be that both gold and fool’s gold look gold. Similarly, the fact that a square looks the same as a triangle that is under a prism is consistent with both the square and the triangle looking square. 6.4 The Veridicality Test Consider the following quotations from Alex Byrne, John Pollock and Susanna Siegel. Alex Byrne writes: ‘Imagine someone with normal vision looking at an object that is shaped and coloured exactly like a red tomato. She might characterize the scene before her eyes by saying that there seems to be a red ripe bulgy tomato before her. Presumably the content of her experience at least concerns the colour and shape of the object. But does it also specify the object before her as ripe, or as a tomato?... Is her experience some kind of illusion if the object is a red but unripe tomato, or if the object is made of papier-mâché?’ (Byrne, 2001, p202). John Pollock writes: [C]onsider the easiest case, which is the case in which it turns out that the wall is all that is left of an old church— there is nothing behind it. When we take ourselves to be seeing a church we are making a mistake, but it is not a perceptual error…. The information encoded by perception is not wrong — it is the judgment we make on the basis of it that is wrong.’ (Pollock, forthcoming, p18). Susanna Siegel writes: ‘The views I’ve just mentioned differ on what the veridicality conditions of visual experience are. The less committal the contents of visual experience, the less misperception there is. For instance, suppose you and your brother come across a bowl full of expertly designed wax fruits. Your brother is fooled into thinking that there are ripe juicy peaches and pears in the bowl: he believes that there are peaches and pears in the bowl, and this belief of his is false. The scene doesn't fool you, let’s suppose, but only because you already believed on some non-perceptual basis—for instance, from reading your daily horoscope's predictions—that you would see some fake fruits today. Because you have this background belief, you suspect trickery, and unlike your brother, you don’t end up believing that there are peaches and pears in the bowl. Might there be in such a case some sort of error in your visual experience, even if not in your belief? A perceptual error would be one from which not even your suspicion protects you: if you misperceive, then your visual experience’s content is false: your visual experience tells you that there are peaches and pears on the table, and that is incorrect. In contrast, if no perceptual error is involved in this case, then the contents of your visual experience are less committal, but correct: they tell you, for instance, that the contents of the bowl have certain colours and shapes.’ (Siegel, 2006, p483). These passages suggest the following test. The Veridicality Test: Necessarily, for all objects x and properties F, if: (i) x is the best or an equal best candidate for a case of an object looking F, and (ii) (iii) x is not F and (i) and (ii) do not provide a reason for thinking that x is being misperceived, then being F is not a visible property. Suppose that one is looking at a wax tomato, O, that looks the same as a paradigm tomato, and is thus an equal best candidate for a case of an object looking to be a tomato. If O’s not being a tomato would not provide a reason to think that an illusion is occurring, then, according to the veridicality test, being a tomato is not a visible property. One problem with the veridicality test is that intuitions differ as to whether an illusion is occurring in cases such as the above. Some will say that no illusion is occurring, and others will say that an illusion is occurring. It is hard to see how one will determine whether an illusion is occurring without resorting to an independent test about which properties are visible and which are not. A second problem with the veridicality test is that it delivers incorrect results for essential properties. For instance, suppose that being shaped is an essential property of any object in which it is instantiated. Condition (ii), therefore, will not be true in any possible world. From a necessarily false antecedent anything follows, including the proposition that being shaped is visible and the proposition that being shaped is non-visible. A test similar to the veridicality test provides a sufficient condition for a property to be visible: The Veridicality Test*: Necessarily, for all objects x and properties F, if: (i) x is the best or an equal best candidate for a case of an object looking F, and (ii) x is not F and (iii) (i) and (ii) provide a reason for thinking that x is being misperceived, then being F is a visible property. A problem for the veridicality test* is that it delivers the wrong results for determinates and determinables. Suppose that being coloured is not an essential property of any object in which it instantiated (for instance, suppose that any object could have been transparent, and therefore colourless). Consider a case of an object, O, that looks red; O is an equal best candidate for an object looking coloured. Suppose that O is not coloured. Since not being coloured entails not being red, and since O looks red, then there is reason to think that an illusion is occurring. The veridicality test* therefore entails that being coloured is a visible property. In effect, the veridicality test* takes it to be trivial that if being red is visible, then being coloured is visible. Even if this conditional is true, it does not seem to be trivially true. 6.5 Behavioural Tests In conversation philosophers sometimes appeal to behavioural data in order to determine what properties visual experience represents. According to one argument, if the way a dog responds when his master walks through the front door is different from the way the dog responds when someone else walks through the front door, this is evidence that the dog’s visual experience can represent that his master has walked through the front door. A premise of the argument is that the dog’s selective behavioural disposition towards his master requires some psychological explanation. One explanation of the dog’s behavioural dispositions is that the dog believes that his master has walked through the front door. Presumably it is an implicit assumption in the argument that dogs are not mentally sophisticated enough to have beliefs, and therefore that an explanation in terms of the dog’s beliefs is not possible. Once this explanation is rejected, it seems that only the perceptual experiences of the dog can explain the dog’s behavioural dispositions. Even if dogs are not mentally sophisticated enough to have beliefs, and therefore if the psychological explanation of the dog’s behaviour cites only the dog’s perceptual experiences, these perceptual experiences need not have rich contents. It is possible, for instance, that the dog is responding to a particular smell when he is near his master, or a particular pattern of colours and shapes that his visual experience represents when he sees his master. The explanation of the dog’s behaviour does not require that the dog’s visual experience represent the property of being a master. Secondly, the proponent of the above argument seems committed to the view that some of the dog’s behavioural dispositions are not explained by any psychological state of the dog. It is natural to explain a given dog’s behaviour when it sees food by saying that the dog wants food. A proponent of the above argument would presumably reject this explanation on the grounds that dogs are not mentally sophisticated enough to have desires. An explanation of the dog’s behaviour in terms of the contents of the dog’s visual experiences would be incomplete. Even if the dog’s visual experience does represent the existence of food, such a state would not explain the dog’s eagerly moving towards the food. Thus it seems that a proponent of the above argument is committed to saying that there is no psychological state of the dog that explains its behavioural disposition in the presence of food. Once this is conceded, however, it is not clear why a proponent of the above argument would insist that there needs to be a psychological state of the dog that explains the dog’s behaviour when it sees its master. 6.6 Neuroscientific Data One might wonder whether certain neuroscientific data provide constraints on which properties are represented by visual experience. A scientist may seek to determine which parts of the brain are active when a subject has a visual experience, and she may try to identify these parts by examining a subject’s responses to his experiences. For instance, a subject may report when he is having a certain kind of experience, and the scientist can correlate that report with a certain pattern of activity in the brain. Alternatively, a brain-damaged subject may not be capable of making certain reports, such as reports about the location of seen objects, and the scientist may be able to use this data to determine the function of the brain-damaged part of the brain. Whether the scientist uses verbal or non-verbal responses of the subject, it seems that she is restricted to these kinds of data when aiming to identify the neural basis of experience. This means that the scientist is identifying, in the subject’s brain, those parts that are responsible for the states of the subject when the subject is responding to his experiences. Call the parts of the brain that the scientist identifies X. If we assume that the existence of responses of the observed kind indicate the existence of visual experiences, then it can be inferred that X is also responsible for the subject having visual experiences. A scientist may also seek to determine in which parts of the brain information about natural kinds is processed, and may try to identify these parts by considering which parts of the brain are active when a subject recognizes a natural kind, and which parts of the brain are such that, when damaged, the subject is unable to recognize a natural kind. Call the parts of the brain that the scientist identifies in this way Y. For all that has been said so far, Y may be a part of X. One might wonder whether the existence or not of channels of information from Y to X could provide evidence that the visual experience of a given subject S represents natural kind properties. Suppose that there is a channel of information from Y to X. It does not seem that this could provide evidence that S’s visual experience represents natural kind properties. It is possible, after all, that the states that S is in when he responds to his experiences, rather than the visual experiences themselves, represent natural kind properties. Suppose that there is no channel of information from Y to X. It is not clear that this shows that S’s visual experience does not represent natural kind information. Y was identified as being responsible for S recognizing a natural kind. It is possible that S’s visual experiences are pre-recognitional states that represent natural kind properties. My argument has been that neuroscientific data of the above kind will not shed light on what properties visual experience represents. I have not argued that it is impossible in principle for neuroscientific data to shed light on what properties visual experience represents. 6.7 The Concept Test If one has a concept, it is natural to wonder how one acquired the concept. For some concepts, it is intuitive that one acquires them because one’s visual experience represents the properties picked out by those concepts. The concept red21 seems to be such a concept. If it turns out that visual experience does not represent the property of being red21, and yet one does have the concept red21, then there is a prima facie challenge to explain how one acquired this concept. One may wonder how one came to acquire concepts such as tomato and water. One explanation is that one’s visual experience represents the properties of being a tomato and being water respectively. However, this explanation is not available to someone who holds a relatively sparse view about the properties that visual experience represents, according to which visual experience does not represent the properties of being a tomato and being water. Thus one might think that there is a prima facie challenge to a defender of a sparse view of this kind to explain how one does come to acquire the concepts tomato and water. It seems that this is a challenge not only for sparse views about what visual experience represents, but for any view that allows that some of our concepts pick out properties that visual experience, or any other kind of perceptual experience, does not represent. Some account of how these concepts are acquired is necessary, and one would need to consider these accounts before deciding whether they would apply to concepts such as tomato and water. In the literature on externalism there is a popular account of how we fix the reference of terms such as ‘water’ and ‘tomato’, and therefore understand sentences containing these terms. This account is related to accounts of concept acquisition since it seems that understanding sentences containing the words ‘water’ and ‘tomato’ is sufficient for having the concepts water and tomato. According to one account within the literature on externalism, we fix the reference of ‘water’ with a definite description. This definite description may either be one such as ‘the stuff in our environment that falls from the sky, fills the lakes and comes out of taps’, or one such as ‘the chemical structure that is common to w1, w2… w10’ where w1, w2… w10 are ostensively demonstrated samples of water. Understanding that the reference of ‘water’ is the reference of these definite descriptions enables us to understand sentences containing the word ‘water’, and thereby acquire the concept water. This is not to say that the concept water is equivalent to the concept expressed by either of the definite descriptions in question, but only that grasping the concepts expressed by the definite descriptions enables us to acquire the concept water. The popularity of this account of how we acquire concepts as water suggests that most philosophers do not think that we acquire these concepts on the basis of our visual experiences representing the properties that they pick out. As it turns out, philosophers who argue that visual experiences represent, say, natural kinds often do so by arguing that visual experience is theory-laden. According to this argument, visual experiences come to represent natural kinds as a result of the subject having certain beliefs about natural kinds. Let us call the argument that a subject’s visual experience represents a certain property as a result of the subject having certain beliefs about that property the theoryladen argument. Clearly a philosopher who employs the theory-laden argument to argue that visual experiences come to represent natural kinds may not also hold that we acquire the concepts of these natural kinds on the basis of our visual experiences representing natural kinds. The theory-laden argument is the standard defence of the claim that visual experience represents a rich range of properties, including properties such as being water. Susanna Siegel writes: ‘First, I will discuss some cases in which a perceiver is disposed to recognize a K-property on the basis of visual experience. I'll argue in each sort of case that such sensitivity makes a difference to the phenomenology of visual experience. Furthermore, I'll suggest, its making a difference to visual phenomenology is a reason to think that visual experiences represent the Kproperty to which the subject is sensitive.’ (Siegel, 2006, p483-4) For Siegel, K-properties are properties ‘other than colour, shape, illumination, motion, and the property of being an object’ (Siegel, 2006, p482). Siegel thinks that a subject’s visual experience comes to represent K-properties because the subject has recognitional abilities for Kproperties. Helen Beebee holds that possessing the concept causation is what makes perceptual representation of causation possible: ‘[T]here is some evidence to suggest that infants as young as six months can ‘perceive causation’ in a simple kinematic sequence… [in a footnote] ‘Perceive causation’ is in scare quotes because the claim should not be taken to be the claim that six-month-olds have thick experience in the sense that they represent kinematic sequences as being causal—since they lack anything like the full-blown concept of causation that would make such representation possible.’ (Beebee, 2003, p266). The following quotation suggests that Peacocke would endorse the theory-laden argument: ‘We see things as tomatoes, and not as anything weaker. If the representational content of experience is given by what someone would judge, taking that experience at face value, then our ordinary experiences have a content concerning tomatoes, and not tomato-like objects.’ (Peacocke, 1983, p93). Given that most philosophers who defend the view that visual experiences have rich contents employ the theory-laden argument, these philosophers are not better-placed at explaining how we come to have the concepts characterizing these contents than the philosophers who argue that visual experiences do not have these rich contents. 6.8 Epistemological Tests Let us call a judgement formed at least partly on the basis of a visual experience a visual judgement. One might wonder about how visual judgements are justified. There are some propositions p such that one’s visual judgements that p are normally justified by one’s visually representing that p. For instance, if one visually judges, of some object O, that O is red21, then normally, this kind of visual judgement is justified by one’s visual experience representing that O is red21. One can also visually judge, of some object O, that O is a tomato, and one may wonder how a visual judgement of this kind is justified. On one account, such a visual judgement is justified by one’s visual experience representing that O is a tomato. However, if one thinks that visual experiences do not represent the property of being a tomato, then one needs to provide an alternative account of how the visual judgement that O is a tomato is justified. As with the concept test, this is not a challenge only to the sparse view, but to any view on which one can visually judge that p without one’s visual experiences representing that p. For instance, looking at a lamp, Jill may visually judge that it would make a good present for Eleanor, and few proponents of rich views of the content of visual experience would wish to say that Jill’s visual experience represents that the lamp would make a good present for Eleanor. Thus most participants in the debate over the richness of the content of visual experience would agree that some account is required of how, for some proposition p, one’s visual judgement that p can be justified without one’s visual experience representing that p. One would need to consider such accounts before one can decide whether they apply to visual judgements about tomatoes. One possibility is that one’s visual judgement that p, for some p, can be justified by one’s ability to produce an inference whose conclusion is p. On this account, Jill’s visual judgement, based on seeing a certain lamp, that it would make a good present for Eleanor, is justified by Jill’s ability to produce an inference such as the following: 1.) The lamp has a striking shape. 2.) If the lamp has a striking shape, then it would make a good present for Eleanor. 3.) The lamp would make a good present for Eleanor. This account does seem to apply to the property of being a tomato. It could be that Jill’s judgement, of some seen object O, that O is a tomato, is justified by Jill’s ability to produce an inference such as the following: 4.) O is that way. 5.) If O is that way, then O is a tomato. 6.) O is a tomato. In this inference, ‘that way’ may refer to a pattern of colours and shapes that Jill’s visual experiences represent. As we saw above in the discussion of the concept test, standard defences of rich views of the content of experience employ the theory-laden argument. That is, they argue that the ability of a subject S visually to represent a particular object as a tomato is related to S’s disposition to judge that something is a tomato. It is not always clear, on these accounts, whether this relation is causal or constitutive; that is, whether it is proposed that S’s visual experience’s representing an object O as a tomato consists in S’s disposition to judge that O is a tomato, or is a causal consequence of S’s disposition to judge that O is a tomato. We can consider each option in turn. Suppose that the fact that S’s visual experience represents that O is a tomato consists in S’s disposition to judge that O is a tomato. On this supposition, it does not seem that S’s visual experience can justify S’s judgement that O is a tomato, since it does not seem plausible that one’s disposition to judge that p can justify one’s judgement that p. Suppose that the fact that S’s visual experience represents that O is a tomato is a causal consequence of S’s disposition to judge that O is a tomato. There does not seem any reason to think that the judgement that S is disposed to make is any more likely to be true because S’s disposition has this effect on his experiences, and therefore, on this supposition, it does not seem that S’s visual experience can justify S’s judgement that O is a tomato. Thus it seems that there are no epistemological advantages of standard defences of the rich view over the sparse view. On neither view are judgements about properties such as being a tomato justified by visual experiences that represent those properties. 6.9 Phenomenological Tests Siegel appeals to phenomenological considerations in order to argue that visual experiences have relatively rich contents. She defines ‘K-properties’ to be properties ‘other than colour, shape, illumination, motion, and the property of being an object’ (Siegel, 2006, p482). She writes: ‘The thesis I will defend is Thesis K: In some visual experiences, some K-properties are represented. … My defence of Thesis K goes as follows. First, I will discuss some cases in which a perceiver is disposed to recognize a K-property on the basis of visual experience. I'll argue in each sort of case that such sensitivity makes a difference to the phenomenology of visual experience. Furthermore, I'll suggest, its making a difference to visual phenomenology is a reason to think that visual experiences represent the K-property to which the subject is sensitive.’ (Siegel, ibid, p482-4). Siegel holds that the investigation of what phenomenological differences occur in visual experience can help determine what properties are represented in visual experience. I agree with Siegel, and argue for this view in chapter 1, where I also consider Siegel’s argument. 7 The Significance Of The Question One might wonder about the significance of the distinction between visible and nonvisible properties. Some have thought that part of the interest in the distinction is epistemological. Siegel holds that what range of properties visual experience represents will determine the range of propositions that visual experiences justify. She writes: ‘It would be odd if … what contents visual experiences had was totally irrelevant to what propositions the experience (together with any other epistemically relevant factors) provided justification for believing. (Siegel, 2006, p488). As we saw in the section on epistemological tests, given the way standard versions of the rich view are argued for, including the way Siegel argues for a version of the rich view, it does not seem that they have the epistemological consequences that Siegel suggests they have. The distinction between visible and non-visible properties seems to me to have considerable intrinsic interest. Its interest does not lie only in its possible ramifications for other areas of philosophy. Part of what makes the distinction interesting is that it is intuitive, and yet hard to grapple with and hard to make precise. Making it precise involves finding a constraint on the notion of a visible property, arguing that it is better than rival constraints and defending it against objections. It is satisfying to think about this problem and to try to develop a clear understanding of it. 8 Chapter Survey In chapter 1 I define a kind of looking, phenomenal looking. Phenomenal looking is defined by the phenomenal character principle, which holds that differences in visual phenomenal character constrain differences in the properties that objects phenomenally look to have. In the chapter I argue that objects phenomenally look to have only colours and positions, and that the colour properties do not include properties such as being red. Although, in this introduction, I have made use of the notion of the content of visual experience, in chapter 1 I explain why, in the rest of the thesis, I will be using only the notion of the properties that objects phenomenally look to have. In chapter 2 I argue for a constraint on phenomenal looking, the phenomenal looking exportation principle, and I argue that the phenomenal looking exportation principle entails that when subjects do not see themselves, objects do not phenomenally look to them to have observer-relative properties, such as being to the left of them and being to the right of them. In chapter 3 I provide three more arguments against the view that the position properties that objects phenomenally look to have are observer-relative properties. These arguments raise the question of what kinds of position properties objects do phenomenally look to have. I consider various other accounts of what kinds of position properties objects phenomenally look to have, and argue that they face serious objections. In chapter 4 I defend a positive view about the position properties that objects phenomenally look to have. According to the view I defend, the position properties that objects phenomenally look to have, which I call phenomenal position properties, are absolute properties, in the sense that they are not relations to any other objects. Furthermore, I argue that necessarily, objects do not have the position properties they phenomenally look to have. Thus, even if objects actually have absolute position properties, these are not phenomenal position properties. My argument is structurally similar to spectrum inversion arguments in the philosophy of colour, and I discuss these arguments. I argue that the most plausible response to these spectrum inversion arguments is to hold that objects do not have the colour properties that they phenomenally look to have. Traditionally philosophers who have been attracted to a sparse view about the properties that objects phenomenally look to have held that objects phenomenally look to have only two kinds of position coordinates: a left/right (x) coordinate and an up/down (y) coordinate. In spite of defending a very sparse view about the properties that objects phenomenally look to have, I hold that objects phenomenally look to have z coordinates in addition to x and y coordinates. In chapter 5 I present an argument for this view. In chapter 6 I discuss how objects would phenomenally look to beings with more coarsegrained discriminatory capacities than us. For instance, suppose that patch1 and patch2 phenomenally look red1 and red2 respectively to one. Consider a being, say a dog, which cannot discriminate the colour that patch1 phenomenally looks from the colour that patch2 phenomenally looks. A question arises as to how patch1 and patch2 phenomenally look to the dog. One hypothesis is that both patch1 and patch2 phenomenally look red1 to the dog, or that both patch1 and patch2 phenomenally look red2 to the dog. In chapter 6 I discuss what alternative hypotheses there may be regarding how patch1 and patch2 phenomenally look to the dog.