Phenomenal Contrast: A Critique* Ole Koksvik University of Bergen and Monash University Forthcoming in American Philosophical Quarterly Abstract A fundamental obstacle to understanding conscious experience is the lack of authoritative methods for determining what the character of a given experience is. Recently, an optimistic consensus has begun to arise, according to which phenomenal contrast arguments can provide answers. This paper argues that important facts about human mental lives systematically block a large class of uses of phenomenal contrast from achieving their aim, and that these minimal pair arguments therefore fail, quite generally. 1 Introduction Conscious experience is important to us. Each of us has a multitude of experiences each day: gustatory, olfactory and visual experiences; moods, emotions, and bodily sensations. Each experience has a phenomenal character: there is something it is like to enjoy it. At any given time, * For discussion or written comments I am indebted to Alma Barner, John Bengson, Berit Brogaard, David Chalmers, John Cusbert, Jonathan Farrell, Alan Hájek, Mette Kristine Hansen, Terry Horgan, Uriah Kriegel, Joanne Lau, Leon Leontyev, Fiona Macpherson, Kelvin Mcqueen, David Pitt, Brian Rabern, Susanna Schellenberg, Susanna Siegel, Nicholas Silins, Declan Smithies, Daniel Stoljar, Weng Hong Tang, Clas Weber, audiences at the 2009 ANU Postgraduate Conference at Kioloa and the 2010 Annual Meeting of the Australasian Association of Philosophy, and an anonymous referee from this journal. 2 each of us also has a global experience with a certain character, there is something it is like overall. We care greatly about the characters of our experiences. Conscious experience is, moreover, crucial to our attempts to understand the world and our place in it, in both every-day and scientific contexts. We know about the world through experience, and decisions of every kind depend on it. In psychology, subjects' reports of conscious experiences are used as data in both experimental and clinical settings. Conscious experience is also important in philosophical inquiry. Some argue, for instance, that the character of some experiences allow certain beliefs to be immediately justified (Pryor 2000, 2004; Koksvik 2011); others that conscious experience is necessary for us to have immediate knowledge of the content of our own thoughts (Pitt 2004); that justification supervenes on conscious experience (Smithies 2006); that conscious experience is part of what makes certain beliefs infallible (Chalmers 2003); or that conscious experience is what makes the content of thought and speech determinate (Horgan and Graham 2012). It is safe to say that conscious experience is of great importance to us, in both a personal, a practical, and a theoretical sense. Despite its importance, many aspects of conscious experience are ill understood. Among the obstacles to improving our understanding is the lack good and authoritative methods for determining what the phenomenal character of a given conscious experience actually is. One might wonder why this matters. Having a headache feels a certain way, and we all know more or less how. That, one might think, is enough. But the problem of missing methods is one to be taken seriously, because many debates hinge on what the characters of experiences actually are. In psychology, the character of experience is part of the data to be explained, different data demands different explanations, and uncertainty about the data translates reasonably directly to uncertainty about theory. In philosophy, the view that an experience's character is exhausted by its content, to take just one example, is open to refutation if two experiences can be found which differ in character but not in content. Evaluating putative instances of such pairs requires that we be able to determine what character these 3 experiences actually have. Because we have no authoritative method for making such determinations, widespread stalemate threatens: two parties may well agree on what follows if a certain experiences have certain characters but disagree about whether or not they actually do.1 So the problem of missing methods is a fundamental challenge to improving our understanding of conscious experience, and of its role and importance in our lives. An optimistic consensus has recently begun to arise, according to which phenomenal contrast arguments can provide answers about the character of experience.2 Against this growing consensus I argue that important facts about human mental lives systematically block a large class of uses of phenomenal contrast arguments from achieving their aim, and that these minimal pair arguments, as I dub them, therefore fail, quite generally. 2 Minimal Pair Arguments Any argument in which a significant role is played by the claim that two or more situations differ from each other with respect to the character of experience could be said to employ phenomenal contrast, but minimal pair arguments constitute a more unified class, similar both in aim and method. The aim of a minimal pair argument is to rationally persuade us that a particular mental feature M contributes to the character of the overall experience of the person who is having it. Pain and perception are uncontroversial examples of mental features that do contribute in this way, but the status of other mental features as contributors is hotly debated. Such arguments have for example played an important role in recent debate about cognitive phenomenology: the view that the mental feature of thinking that p-say, that snow is white-makes a different contribution than 1 This case from the early history of psychology illustrates the situation: "[T]here is always to be remembered that famous session of the Society of Experimental Psychologists in which Titchener, after hot debate with Holt, exclaimed: 'You can see that green is neither yellowish nor bluish!' And Holt replied: 'On the contrary, it is obvious that a green is that yellow-blue which is just exactly as blue as it is yellow'" (Boring 1946, 176). 2 The term is so far as I can tell due to Susanna Siegel, see her 2006a and 2007, and also her 2006b and 2009. For discussion, see also Kriegel (2007), and Kriegel and Horgan (2013). Others signal their acceptance of the method by using it; numerous examples follow. 4 the mental feature of thinking that q-say, that grass is green-but have, as we shall see, been put forward for many other mental features too. As for the method, minimal pair arguments proceed by describing a pair of situations in which a person might find herself. There are three crucial desiderata for this description. First, the situations should of course differ from each other with respect to the crucial mental feature M, the one which the proponent seeks to establish is a contributor. This desideratum is practically always fulfilled, usually by stipulation. Second, the situations should approximate a truly minimal pair: situations which differ only in M. Finally, the description should produce a clear reaction that what it would be like to be in one of the situations differs from what it would be like to be in the other: the phenomenal character of the overall conscious experience would differ. In the ideal case the audience has no doubt about this. As the pair is truly minimal, no explanation of this fact can be given in terms of differences in acknowledged contributors, mental features which both sides take to be contributors. This gives rise to pressure to acknowledge a new contributor. Since M is the only difference between the two situations, M must be it. In practice, the second and third desiderata pull in opposite directions: the closer we come to a truly minimal pair, the less certain we are that there would be a difference in the phenomenal character of overall experience; the more certain we are of this, the further we are from a truly minimal pair, and the less pressure there is, therefore, to conclude that M is responsible. Responding to this pressure, actual instances of minimal pair arguments describe situations that approximate minimal pairhood more or less closely (hence the name), without attaining it. Actual instances of minimal pair arguments are therefore inferences to the best explanation, and in this respect stand in contrast to their regulative ideal; the limiting case of such inferences, in which just one explanation is available. In regimented form, minimal pair arguments look like this: 5 (1) If a person were to find herself in one of the described situations, she would be different with respect to M from what she would be in the other (2) The character of her overall experience would also differ (3) That M contributes to the character of overall experience is the best explanation for the difference mentioned in (2) (4) So, we have good reason to believe that M contributes to overall experience Here the tension is between premises (2) and (3): as the plausibility of (2) increases the plausibility of (3) diminishes, and vice versa. Note carefully that minimal pair arguments by stipulation invoke what I will call the general explanandum; namely the existence of a difference in the phenomenal character of overall experience. That is how premise (2) is to be understood. The critique I present below is directed specifically to minimal pair arguments as thus understood. Other arguments invoke different explananda, and we consider some of them in § 5.2 below. However, minimal pair arguments understood in this way play an important role in the literature. To show this is the business of the next section. 3 Examples from the Literature I claim that minimal pair arguments, as that term has just been explained, play an important role in recent philosophical literature. To see this, consider the following examples. EXAMPLE 1: COGNITIVE PHENOMENOLOGY. In The Significance of Consciousness, Charles Siewert argues that there is content-specific cognitive phenomenology: [O]n some occasions someone utters a sentence, and you momentarily understand it one way . . . and then are struck by the realization that the speaker meant something else altogether. . . . [O]ne can note a difference in the way it seems to understand it, depending on which way one takes the story. And this is so even if one does not 6 picture anything differently, or picture anything at all, as one interprets it differently (Siewert 1998, 278 – 9).3 Here is a reasonable interpretation of Siewert. A person might find herself in either one of two very similar situations, such that in one she understands a recent utterance one way; in the other, a different way. The content of her thought (M) would be different in the two situations (premise 1). What it would be like to be her would also be different; the phenomenal character of her overall experience would differ (premise 2), even if she did not visually imagine different things. The best explanation for this is that thinking a thought with one content makes a different contribution to the character of overall experience than thinking a thought with a different content (premise 3). So, we have good reason to believe that this is so. RECOGNITIONAL CAPACITIES. In 'Which Properties are Represented in Perception?', Susanna Siegel argues that exercising one's ability to recognise a natural kind contributes to the character of one's overall experience: Suppose you have never seen a pine tree before, and are hired to cut down all the pine trees in a grove containing trees of many different sorts. . . . [Y]our disposition to distinguish the pine trees from the others [gradually] improves. Eventually, you can spot the pine trees immediately. . . . Gaining this recognitional disposition is reflected in a phenomenological difference between the visual experiences you had before and after the recognitional disposition was fully developed (Siegel 2006b, 491). 3 I take the content of experiences and thoughts to be their accuracy conditions, and assume that they have content in this sense; see for example Siegel (2005/2010) and Siewert (1998, §§ 6.2 and 8.4). Minimal pair arguments play an important role in Siewert's overall argument (see especially his § 8.3), but certainly do not exhaust it. Pitt (2004) might also appear to argue in this way, but his intention is to draw attention to the type of phenomenology he claims exists (for more on this, see § 5.3 below). Horgan and Tienson (2002), Horgan and Graham (2012), Kriegel (2003) and Peacocke (1998) can also be understood to use minimal pair arguments to support the claim that there is content-specific cognitive phenomenology. In contrast, Jacob (1998) argues that there is not cognitive phenomenology; Tolhurst (1998) that there is a distinction between a 'mere desire' and a 'felt demand', and Kriegel (2007) that there is non-sensory phenomenology (see also Kriegel 2003). 7 Here is a reasonable interpretation of Siegel. A person might find herself in either one of two very similar situations, such that in one but not the other a capacity to immediately recognise pine trees (M) is exercised (premise 1). The phenomenal character of her overall experience would differ in the two cases (premise 2), and the best explanation for this is that exercising a capacity to immediately recognise pine trees contributes to the phenomenal character of a person's overall experience (premise 3). So we have good reason to believe that this is so.4 UNDERSTANDING. In Mental Reality, Galen Strawson argues that there is something it is like to understand a sentence: [D]oes the difference between Jacques (a monoglot Frenchman) and Jack (a monoglot Englishman), as they listen to the news in French, really consist in the Frenchman's having a different experience? . . . It is certainly true that Jacques's experience when listening to the news is very different from Jack's. And the difference between the two can be expressed by saying that Jacques, when exposed to the stream of sound, has what one may perfectly well call . . . 'an understandingexperience', while Jack does not (Strawson 1994/2010, 5-6). Here is a reasonable interpretation of Strawson. A person might find herself in either one of two very similar situations, such that she understands a sentence she hears (M) in one situation but not in the other (premise 1). What it would be like to be her would be different in the two cases-the phenomenal character of her overall experience would differ (premise 2). The best explanation for this is that understanding a sentence contributes to the phenomenal character of overall experience (premise 3). So we have good reason to believe that this is so. 4 Kriegel (2007) argues in similar fashion that 'being mommy's face', and a figure (e.g., duck/rabbit) looking a certain way, are represented in experience; Horgan, Tienson, and Graham (2003) that taking oneself to perform an action voluntarily is; Siegel (2006a) that subject independence, perspectival connectedness and causation are. See also Brogaard (2013), who offers four responses to Siegel's argument. 8 PHENOMENOLOGY OF AGENCY. In 'The Phenomenology of First Person Agency', Horgan, Tienson and Graham argue as follows: Suppose that you deliberately perform an action-say, holding up your right hand and closing your fingers into a fist. . . . [The experience of doing that] is certainly not like this: first experiencing an occurrent wish for your right hand to rise and your fingers to move into clenched position, and then passively experiencing your hand and fingers moving in just that way (Horgan, Tienson, and Graham 2003, 327 – 8). Here is a reasonable interpretation of these authors. A person might find herself in either one of two very similar situations, such that she takes herself to perform certain actions voluntarily (M) in the first situation but not in the second (premise 1). The phenomenal character of her overall experience would differ in the two cases (premise 2), and the best explanation for this is that taking oneself to perform an action voluntarily contributes to the phenomenal character of conscious experience (premise 3). So we have good reason to believe that this is so. I have shown that these influential recent uses of phenomenal contrast are reasonably interpreted as minimal pair arguments, in the specific sense I have given to that term, and in the attendant notes I have pointed to many other examples. I claim that many more uses of phenomenal contrast are both reasonably and in fact (in the literature) understood as minimal pair arguments. Given this it is highly significant that, as I will now argue, they all fail: they cannot rationally persuade us. 4 Minimal Pair Arguments Fail Imagine someone who doubts that perception has content-specific phenomenology (Koksvik 2011, p. 104): that perceiving something green makes a different contribution than perceiving something red. 9 How might you rationally persuade her that it does? Perhaps you would be tempted to argue as follows: CINEMA SCREEN ARGUMENT : Imagine that you are sitting in a comfortable seat in the middle of a dark movie theatre. You are not in pain, you are not hungry or thirsty, and you are sitting still. The screen turns a uniform green. You stare at the screen, concentrating on it. This is the first situation. You relax, closing your eyes. When you open them again, the screen is a uniform red. You stare at it, concentrating on it. This is the second situation. Clearly, the character of your overall experience would be different in the two situations. The best explanation for this is that perceiving something green makes a different contribution to experience than perceiving something red. I agree that this argument seems convincing. But it is not in fact rationally persuasive: we should resist its pull and not be convinced. Arguments are rationally persuasive only given (actual or hypothetical) agreement on a set of background facts, and against some but not all such backgrounds. Let us therefore suppose that you and your interlocutor agree that occurrent, remembered and imagined bodily sensations, moods and emotions all contribute to the phenomenal character of a person's overall conscious experience, and that attention modifies the contribution each of these makes. This common ground, call it CG1, is a useful starting point, since its claims are accepted by virtually all recent proponents of minimal pair arguments. Now note two truths about human mental lives, which I shall simply assume are universal: 10 Richness: At most times there is a lot going on in our mental lives: several remembered, occurrent and imagined bodily sensations, moods and emotions occur at the same time (or near enough). Our mental lives are rich with activity. Flux: Most of these goings-on are evanescent; a remembered bodily sensation may last only a fraction of a second, attention changes around often, and so on. Our mental lives are in constant flux. Showing that minimal pair arguments fail is now straightforward. Since human mental lives are rich with activity, a large number of the contributors acknowledged by CG1 will obtain at any given time. Given Flux, the set will be very different at any other time (barring an astronomical coincidence). Minimal pair arguments by stipulation invoke the general explanandum: the existence of a difference in the phenomenal character of the person's overall conscious experience (premise 2 above). That is what the best explanation is supposed to be an explanation of. But, there are just as many candidate explanations of that explanandum as there are differences between the two sets of contributors. After all, to be a contributor just is to (be able to5) make a difference to the phenomenal character of a person's overall conscious experience. Moreover, precisely because what is to be explained is the existence of a difference, anything that is capable of producing such a difference constitutes an equally good candidate explanation as anything else so capable.6 Given this, it just follows that each of the myriad alternative explanations for the existence of a difference in the character of overall 5 The contribution of a mental feature may in certain circumstances be 'drowned out' by other contributions: think about being gently tickled with a feather when undergoing amputation of a leg without pain relief. This does not jeopardize the feature's claim to being a contributor, nor does it undermine my argument in any way. 6 On the assumption that each contributor equiprobably contributes. In no extant contrast argument of which I am aware does differences in the probability of contribution play any role, so I set this complication aside. 11 experience is just as good as the hypothesis that M is a contributor. That hypothesis is therefore not the unique best explanation of the datum-far from it. So premise (3) is false, and the argument fails. 5 Objections and Replies I Objections to the present critique are usefully divided into two groups. Those in the first group accept that the general explanandum is operative, those in the second deny this. In this section I discuss only objections in the first group. 4.1 Stipulation The Cinema Screen Argument specifies that the subject is not in pain, not hungry or thirsty, and is sitting still. The purpose of this is to exclude these things as possible explanations for the existence of a difference in overall experience. Such specifications are common, and rhetorically important. With these exclusions in place, there is still a strong reaction that there would be a difference in the character of overall experience. However, since the explanandum of a minimal pair argument is the existence of a difference in the character of the person's overall conscious experience, there are as many candidate explanations as there are differences between the sets of contributors in the two situations, each as good as every other. Minimal pair arguments could therefore rationally persuade us that M is a contributor only if all the other explanations could be excluded. Given this, their proponents must be understood to invite us to believe that the list of exclusions could be extended to include all acknowledged contributors except only M, with no difference in the result. That invitation should be resisted. On any reasonable common ground the list of acknowledged contributors is long, and the listed exclusions give us no reason to believe that none of the other contributors differ between the situations. In our example argument, differences in 12 occurrent bodily sensations other than pain, hunger and thirst, differences in occurrent moods and emotions, as well as differences in remembered and imagined bodily sensations, moods, emotions, and attention, all these are in play, and each difference makes possible an explanation just as good as every other. Each makes possible an explanation as good as every other because-I reiterate ad nauseam-the explanandum is the existence of a difference in the phenomenal character of the person's overall conscious experience, and because each contributor is capable of producing such a difference. That is what it is to be a contributor. The objection I now want to consider counters by simply stipulating that there are no other differences between the two situations. We have already noted a problem with this strategy: the more closely we approximate a truly minimal pair, the less clear our reaction that there actually would be a difference in the phenomenal character. For my own part, when I consider the Cinema Screen case and try to imagine that there is no difference between the situations other than the difference in the projected colour, methodically excluding one by one all the other contributors, the situation soon becomes too alien, and I no longer have any intuition about it. On reflection this is easy to understand: my mental life is characterised by Richness and Flux, and what I am trying to imagine is that these deep facts about me no longer hold. No wonder my imagination gives out! It is important to forestall a certain confusion here. The Cinema Screen Argument has a very plausible conclusion: there is content-specific phenomenology of perception and we all know this. Moreover, applying our existing knowledge to the case is quick and easy: since we know that the situations differ in content we can infer that they differ in overall experience. But this knowledge does not arise from the case, and is obviously of no help when the aim is to rationally persuade precisely someone who lacks it. What is needed then is a clear intuition about the case as described. That is what I lack. The general fact that the closer we approximate a truly minimal pair the less clear our reaction that there would be a difference in phenomenal character is the first problem with the stipulation strategy. It is already sufficient to undermine it. 13 Second, even were someone to sincerely report such an intuition, having given us reason to trust that she had carefully and methodically attempted to exclude all other contributors from the case she held in mind, I think we should have reason to be wary. Our intuitions about what it would be like to be in a certain counterfactual situation are likely to be heavily influenced by our previous experiential history. Since our mental lives are characterised by Richness and Flux it is overwhelmingly likely that all our experiences are from situations that differ from each other in many contributors. Therefore, even if we try to respond to the case as described, our past experience is likely to overwhelm our attempts, so that our judgements reflect that past experience rather than the case as described. For this reason, intuitions about such cases should not be given weight, and the stipulation strategy offers no help to the proponent of minimal pair arguments.7 It is important to acknowledge that minimal pair arguments seem persuasive. I think we can begin to see why by noting that, when we consider such arguments, we are probably sensitive to counterfactual conditionals such as: if a person were to find herself in situations such as those (originally) described, there would be a difference in her overall experience. This conditional is, of course, true: in close possible worlds human beings are a lot like us, so their mental lives are substantially characterised by Richness and Flux. Consequently, between any two situations there are for them, just as there is for us, differences in many contributors. So the counterfactual is true. I suggest that the false allure of minimal pair arguments is at least partly explained by our responding to counterfactuals such as this one even when we try to consider cases where all acknowledged contributors are excluded by stipulation. And, of course, one often does not even make an effort to exclude all acknowledged contributors, but contents oneself with excluding just a few of those that first come to mind, such as, for example, visual imagination. 7 This does not lead to wholesale skepticism about intuitions, as there is a special reason to be concerned here. 14 4.2 Memory A proponent of phenomenal contrast which accepts that the general explanandum is operative might instead claim to remember situations that differ only in some mental feature M and in the phenomenal character of overall experience. Such situations would constitute truly minimal pairs, and would force the conclusion that M is a contributor. Faced with this strategy, we need to note a further fact about our mental lives: Poor Identification and Remembrance: A large proportion of the episodes that contribute to the richness of our mental lives are of short duration, and are not paid much notice. For this reason, and because our introspective abilities are just not that acute, our mental goings-on are often poorly identified. A mental goings-on which is not correctly identified at the time of occurrence will not be correctly remembered later, and of those that are correctly identified, many fail to be committed to memory. Our mental goings-on are usually poorly remembered. Our mental lives are characterised not only by Richness and Flux but also by Poor Identification and Remembrance. Therefore, although there undoubtedly are pairs of situations about which we can only remember the difference in, say, perceived colour and overall character, this is not good evidence that those really were the only differences between the two situations. Given Richness and Flux, we have every reason to believe that we experience no such pairs, and so do not remember any. So this response also fails.8 8 Some might worry that Richness, Flux, and Poor Identification and Remembrance are jointly self-undermining. If we are so bad at identifying and remembering our mental goings-on, how can we know that our mental lives are characterised by Richness and Flux? Here is how. We do not usually focus our attention on our experiences, but we can. The richness of the experience is then revealed to us, and its fluctuating character likewise. Even just within tactile phenomenology, for example, there is a lot going on, and there are rapid changes. In one moment I am strongly aware of the feel of the soles of my feet, a moment later my typing fingertips typing dominate the tactile phenomenology, then a slight back-pain, the feeling of the arm-rest under my arm, the feeling of my body making contact with the chair, and so on. As I shift my attention around, what is in focus comes to make a more significant contribution to the character of my experience. One can easily see that the same goes for other types of perceptual phenomenology by switching one's attention to, say, auditory 15 4.3 Some Explanations Are Better A common reaction to the present critique is to deny that each of the competing possible explanations are as good as all the others. There are two ways to understand this reaction. I think it is usually best understood as embodying the claim that the relevant contrast arguments do not invoke the general explanandum after all (and so are not minimal pair arguments in my sense). Such responses are considered in § 5 below. However, one can also imagine objecting in this way while accepting that the general explanandum is operative. What could support this contention? It cannot be that variance in certain contributors is irrelevant. An acknowledged contributor just is a mental feature acknowledged by both sides to be capable of contributing to the character of overall experience. Anything capable of doing that is, clearly, relevant when the existence of a difference in overall experience is to be explained. The only remaining option I can see is to appeal to general considerations of theory choice to favour one explanation over another. To my knowledge no-one has actually taken this tack, and the outlook is not favourable. On any reasonable interpretation of the criterion of ontological parsimony, for instance, it either counts against acknowledging a new (new) contributor, or it is neutral on the matter (perhaps because the contributor is of the same kind as one already acknowledged). So there is little chance of resisting the argument in this manner. We have considered three styles of objections which accept that the general explanandum is operative: one that relies on stipulating that no other contributors differ between the two cases, one which relies on a claim to remember this, and one which claims that some explanations are better. All three objections fail. phenomenology. If contributors do not contribute to overall phenomenology only when in focal attention- which I assume without argument-we also come to know that there are contributions that we do not recognise at the time, and so do not remember. So many contributors go unnoticed and without being remembered, not just one or a few. So Richness, Flux, and Poor Identification and Remembrance do not undermine each other. 16 5 Objections and Replies II We now turn to objections which deny that the relevant explanandum is the general one. 5.1 No examples The Cinema Screen Argument is a constructed example, so its failure is unimportant on its own, and a common objection is that the critique misunderstands which explanandum proponents of phenomenal contrast 'really' intend to invoke. Put differently, since minimal pair arguments by stipulation invoke the general explanandum, there are few if any real examples of such arguments, so any critique against them, whether effective or not, is inconsequential. Or so the objection goes. If this were true, it would constitute an important objection. But it is not true. In § 3 I argued in detail that four influential recent examples of the use of phenomenal contrast are reasonably interpreted as minimal pair arguments in the sense outlined. I also claimed for numerous other examples that they both reasonably and often in fact are interpreted in just this way. Those who wish to press the objection currently under consideration must show why these arguments and claims should be rejected. But those who explicitly discuss phenomenal contrast are usually best interpreted as taking the general explanandum to be operative,9 and indeed often make it absolutely clear that they see things this way, for example in their regimentation of the arguments.10 The prospects for this line of argument are therefore dim, and the failure of the Cinema Screen Argument demonstrates the failure of these other arguments as well. 5.2 Thicker explananda Some claim that phenomenal contrast arguments 'really' rely on different explananda than the general one. I have just argued against this objection on the grounds that it misrepresents the literature, since many recent influential uses of phenomenal contrast clearly do advance minimal pair 9 See, for example, Siegel (2006a, p. 371; 2007, p. 136); Kriegel (2007, p. 126), and Bayne (2012, p. 62). 10 See, for example, Siegel (2006b, p. 491), Kriegel and Horgan (2013), and Brogaard (2013, p. 36). 17 arguments, in my sense. I now wish argue that even if we were to accept the claim, the prospects for the arguments are dim. The objection now under consideration claims that what really calls out for explanation is a more substantial or specific fact than the mere existence of a difference in character of overall experience. I can see four variations on this strategy, which each take a different fact to be what really needs to be explained. First, it might be claimed that, while some of the difference in experience can be explained by acknowledged contributors (mental features which both sides agree are contributors), the difference between the two situations is too 'large' to be so explained, and that to explain the entire difference, reference must be made to variance in M. Call this 'the magnitude reply'. Second, it might be claimed that the difference is partly of a kind such that the differences in other contributors cannot explain (a certain aspect of ) it. Call this 'the kind reply'. Third, it might be claimed that if we iterate the cinema screen experiment with different colours, the person will be aware that the differences are not the same in each case. Call this 'the different difference reply'. Finally, it might be claimed that if we repeat the cinema screen setup while systematically varying other features of the situations (but not the colours projected), the person will be able to recognise an aspect of the overall difference each time, and that this stable aspect is the real explanandum. Call this 'the persistent difference reply'. None of these strategies holds much promise. First, the magnitude reply fails because it relies on implausibly denying Poor Identification and Remembrance. The reply claims that the magnitude of difference between the two situations cannot be accounted for. But that claim cannot be motivated, since we have, for each alleged instance, excellent reason to believe that there were differences in (acknowledged) contributors between the situations which we do not now remember, 18 and which will help to explain the magnitude of difference. This might either be because they were not correctly identified at the time of occurrence, or because we simply do not commit all aspects of an experience to memory. Put differently, the magnitude reply says that there is a larger difference than we can account for with acknowledged contributors, but overlooks the point that there are more contributors to employ for this explanation than those which we remember after the fact. Moreover, the reply relies on implausibly strong abilities to accurately estimate magnitudes of difference in overall experience, to accurately estimate how much difference is attributable to a particular contributor, and to accurately add these together. Absent this we could not tell that the difference is larger than what can be accounted for by acknowledged contributors.11 Since we in all likelihood cannot do this with any degree of accuracy, the magnitude reply fails for this additional reason. Consider next the kind reply. The proponent wishes to demonstrate that acknowledged contributors cannot explain a certain difference in experience (or that acknowledged contributors cannot explain that difference as well as the hypothesis that M contributes can) and that acknowledging M as a contributor is therefore needed. But her opponent holds, precisely, that acknowledged contributors can explain all there is to explain. (This is so in the recent cognitive phenomenology debate, for instance.) In this dialectical situation, the proponent cannot simply take as her datum that there is an experiential difference between the two situations which acknowledged contributors cannot explain (equally well). She will then have assumed what she set out to demonstrate. That is what begging the question is. To rationally persuade, the proponent must start from a datum about which there is agreement. The existence of a difference in overall 11 The very least that would be required are abilities to classify an overall change as too large to be accounted for by changes in certain other contributors. Thanks to Clas Weber for discussion here. Of course, I need not and do not claim that we have no such abilities whatever. 19 conscious experience is precisely that, which explains its prominent role in the literature.12 (We return to an amended version of the kind reply in § 6.) Taking a different difference as one's starting point obviously does not help. The present critique points out that our minds are characterised by Richness and Flux. Given this we should expect that the differences between the two situations will differ between iterations of the Cinema Screen setup, since many contributors will very between iterations. This datum is thus easily explained without reference to variance in M. In the persistent difference reply, the alleged datum is an aspect recognised across iterations. Can the existence of this alleged datum be adequately supported? One strategy would be to say that we have been through similar iterations in real life, and remember such common aspects of changes in our experiences. To take this tack is to place a strong bet on our abilities to identify, separate out, and remember detailed aspects of our conscious experience. Things often taste, feel, sound and look very different from how we seem to remember them, so we have good reasons to doubt that we have such strong abilities. Can we perhaps intuit that an aspect of what changed from one situation to the next would be invariant across iterations of the setup? I do not have this intuition. We can, as before, apply previous knowledge to the cases, and in this way come to know that there would be a persistent difference across the iterations. But we must clearly distinguish this from an intuitive reaction to the case as described. The latter would support the minimal pair argument, but the former cannot. Would the proponent have what she needed if we bracketed this concern, and granted the purported datum? Not obviously. In Figure 1, p1 and p2 are two different characters of overall experience, a and b are perceptions with different content (a green screen and a red screen, for 12 Alternatively, the proponent could first try to bring about agreement about the existence of new datum. She might aim to acquaint the opponent with a new experience, or persuade her through argument or demonstration of its existence. But phenomenal contrast arguments do not play out in the setting of people not having been exposed to a relevant range of experiences, or who are inattentive to or unreflective about experience. Quite the contrary. So there is not much hope here. Thanks to David Pitt for discussion. 20 example), a1 and a2 are associated states, and a1≠ a2. The proponent wishes to establish that what is perceived directly contributes to the character of a person's overall experience; it makes such a difference by itself. She thus wishes to endorse the picture on the left but reject the picture on the right. But remembering a persistent difference is not enough for this. Figure 1 If associated states intervene between the content of perception and the character of overall experience, whether the difference is attributable to perception in the right way depends on what those states are. If the intervening states themselves are acknowledged contributors, the conclusion cannot be established. Moreover, it is plausible that the common ground must rule out the intervening states as contributors for the conclusion to be established. For if it is an open question by the lights of the common ground whether the associated state is a contributor, how could the argument establish that it is M which explains the difference? To illustrate, let a1 and a2 be slight emotional reactions. A pleasant green may be stably associated with one emotional reaction (a1) and a garish red with another (a2). (If you live in a place with peak-hour traffic, you know what I mean.) On CG1, emotions are contributors, so the datum could be explained without appeal to M. p1 a p 2 b p 1 a p 2 b a 1 a2 21 For this type of reply to work, then, two significant hurdles must be overcome. First, the existence of the datum must be established. Second, the existence of an intervening state that is itself a contributor must be ruled out. But there is no reason to think this can be accomplished. 5.3 Ostension The aim of minimal pair arguments is to rationally persuade us that a particular mental feature contributes to the character of experience. But this is not the only way phenomenal contrast might be used: it could instead be used as a way of 'pointing'.13 It is natural to understand such ostensive uses as targeting those who are in at least approximate agreement with the proponent with respect to contributors. Such uses can also be understood to have a particular aim, namely to assist the audience in focusing attention on certain features of their conscious experience, or to make those features easier to appreciate. The Cinema Screen Argument is most naturally understood as, precisely, an argument, and § 3 above proceeds from this perspective, but the case might also be used ostensively. And it is in general possible to understand at least some uses of phenomenal contrast as ostensive.14 The present critique might, if sound, indicate uncertainty in what is being pointed to in such cases, but nothing here hinges on this.15 A proponent who clarifies that she never aspired to rational persuasion does not contest my conclusion. Moreover, many uses of phenomenal contrast are, as we have seen, reasonably understood as presenting minimal pair arguments, properly speaking. 13 I do so myself in my 2011, Chapter 5. 14 Some of those who argue for content-specific cognitive phenomenology also say that a difference in the content of thought would metaphysically necessitate a difference in phenomenology. Perhaps most of the argumentative weight is placed on the considerations presented in favour of that view. See Horgan and Tienson (2002) and Pitt (2004). 15 Thanks to Jonathan Farrell for discussion here. 22 6 Concluding Remarks I end by considering an amendment to the kind reply, since this is revelatory of the commitments which I think defenders of minimal pair arguments will have to take on. We saw that the unamended kind reply begs the question. But perhaps we could begin at the other end, fixing our attention on the difference between the situations, and then comparing each of the many alternative explanation which Richness and Flux throw up to the thesis that M contributes.16 Once it is clarified what this procedure actually entails I trust that the cost of adopting this response will become clear. First, we must recognise the limits of our introspective abilities: we cannot simply direct our attention to our experience and become aware of exactly what it is like to have it (see, e.g., Schwitzgebel 2008, Smith 2012). The amended kind reply requires a clear grasp, not just of one situation, but of two, and moreover accurate comparison between them. This will obviously at best be highly tentative, and this uncertainty already dramatically lowers the probability that a single explanation will stand out as the unique best one. Second, since our mental lives are rich with activity and in constant flux, there are, as I have emphasised, many, many possible explanations for why this not-too-determinate difference should obtain. We must not only consider all the contributors that vary between the two situations-many of which we have already forgotten, thus already demonstrating the futility of the effort-we must also consider all their various combinations (since contributors may affect each other; see Koksvik Forthcoming), as well as the effects of attention being modulated in different ways. As far as I can tell, those who respond to the present critique by adopting the amended version of the kind reply are committed to our being able to methodically work through this long list of candidate explanations, and somehow be able to tell that M contributing to overall experience outperforms them all. If the foregoing critique is correct, this approach could only be successful if our 16 Thanks to Susanna Siegel for discussion. 23 introspective, imaginative and comparative abilities were much better than in fact they are, or if our lives were not characterised by Richness, Flux, and Poor Identification and Remembrance (or both). The amended kind reply thus does not add any independent force; the present critique must be resisted at an earlier point. Defenders of minimal pair arguments should tell us where. 24 References Bayne, Tim. 2012. The Unity of Consciousness (Oxford University Press). Boring, Edwin G. 1946. 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