Formerly a spectral apparition that haunted behaviorism and provided a puzzle about our knowledge of other minds, the inverted spectrum possibility has emerged as an important challenge to functionalist accounts of qualia. The inverted spectrum hypothesis raises the possibility that two individuals might think and behave in the same way yet have different qualia. The traditional supposition is of an individual who has a subjective color spectrum that is inverted with regard to that had (...) by other individuals. When he looks at red objects, this individual has the qualia normally produced in others by blue objects. And when presented with a blue object, this individual experiences qualia that most persons experience only when presented with red objects. And so forth - the Invert's color spectrum is the inverse of normal; there are systematic inter-subjective differences in qualia. (shrink)

If you trained someone to emit a particular sound at the sight of something red, another at the sight of something yellow, and so on for other colors, still he would not yet be describing objects by their colors. Though he might be a help to us in giving a description. A description is a representation of a distribution in a space (in that of time, for instance).

A version of the inverted spectrum thought experiment that disconfirms functionalism for the case of humans’ color experiences has typically been thought to require a certain kind of balancing act. What one needs, it has typically been thought, is a mapping of color experiences onto other color experiences that preserves the similarity and difference relationships among those experiences and the aspects of perceived colors underlying those similarities and differences. However, there are good reasons for being suspicious about whether (...) that is possible when the palette of color experiences is that available to humans with normal vision. The new version of the thought experiment constructed here doesn’t depend on preserving those relationships. I argue that there is a coherent, metaphysically possible scenario in which two human color experiences—any two—can be seen to be functionally equivalent. The upshot is that functionalism fails for all human color experiences. (shrink)

If you trained someone to emit a particular sound at the sight of something red, another at the sight of something yellow, and so on for other colors, still he would not yet be describing objects by their colors. Though he might be a help to us in giving a description. A description is a representation of a distribution in a space (in that of time, for instance).

Intentionalism holds that two experiences differ in their representational content if and only if they differ in phenomenal character. It is generally held that Intentionalism cannot allow for the possibility of spectrum inversion without systematic error, unless it abandons the idea that, for example, the qualitative character of color experience is inherited from the qualitative character of colors. The paper argues that the conjunction of all three -- the possibility of spectrum inversion, Intentionalism, and the inheritance thesis -- (...) can be consistently, and plausibly, accepted. (shrink)

The objective of this paper is to defend the non-reductive thesis of phenomenal consciousness. This paper will give an overview of the arguments for the non-reductive explanation of phenomenal consciousness and justify why the reductionist approach is implausible in the context of explaining phenomenal subjective experience. The debate between reductionist and non-reductionist on the project of demystifying and mystifying phenomenal consciousness is driven by two fundamental assumptions-1) Reductive-Naturalistic Objectivism, 2) Phenomenal Realism. There are several arguments for the irreducibility of phenomenal (...) consciousness; this paper will focus on the inverted spectrum argument, knowledge argument, and the conceivability argument. (shrink)

To the familiar idea of an undetectable spectrum inversion some have added the idea of inverted earth. This new combination of ideas is even harder to make coherent, particularly as it applies to a supposed inversion of black and white counteracted by an environmental switch of these. Black and white exhibit asymmetries in their connections with illumination, shadow and visibility, which rule out their being reversed. And since the most saturated yellow is light and the most saturated blue (...) dark, yellow and blue could not be reversed unless light and dark could be. The difficulties suggest some more general morals for how to think of the role of 'qualia' in colour perception. (shrink)

In ‘Wittgenstein and Qualia’ Ned Block argues for the existence of inverted spectra and those ineffable things, qualia. The essence of his discussion is a would-be proof, presented through a series of pictures, of the possible existence of an inverted spectrum. His argument appeals to some remarks by Wittgenstein which, Block holds, commit the former to a certain ‘dangerous scenario’ wherein inverted spectra, and consequently qualia live and breath. I hold that a key premise of this (...) proof is incoherent. Furthermore, Block’s dangerous scenario does not follow from Wittgenstein’s innocent one, as Block believes it does, but rather is in conflict with it. (shrink)

Michael Tye’s considered position on visual experience combines representationalism with externalism about color, so when considering spectrum inversion, he needs a principled reason to claim that a person with inverted color vision is seeing things incorrectly. Tye’s responses to the problem of the inverted spectrum ( 2000 , in: Consciousness, color, and content, The MIT Press, Cambridge, MA and 2002a , in: Chalmers (ed.) Philosophy of mind: classical and contemporary readings, Oxford University Press, Oxford) rely on (...) a teleological approach to the evolution of vision to secure the grounds upon which people with normal color vision can be justly called ‘right’ and those with inverted color vision can be called ‘wrong’. I demonstrate that since the inverted spectrum thought experiment requires that both sorts of vision be behaviorally indistinguishable, no biologically acceptable concept of teleology will allow Tye to draw the distinction he needs. (shrink)

It is possible for a person and their environment to be physically identical each day and yet the representational content of their beliefs about color are inverted. Each day they utter the same words, ‘Wow! The colors of everything have switched again today.’ In uttering these words, they express a different proposition each day. This supports the view held by Reichenbach and Carnap that when it comes to representations of colored objects, relations of similarity and difference are fundamental. There (...) are no such things as colors like ‘redness’ and ‘greenness’ apart from the particular things we call red and green. (shrink)

There has been much written in recent years about whether a pair of subjects could have visual experiences that represented the colors of objects in their environment in precisely the same way, despite differing significantly in what it was like to undergo them, differing that is, in their qualitative character. The possibility of spectrum inversion has been so much debated1 in large part because of the threat that it would pose to the more general doctrine of Intentionalism, according to (...) which the representational content of an experience fixes what it. (shrink)

Proponents of the hard problem of consciousness argue that the zombie and inverted spectrum thought experiments demonstrate that consciousness cannot be physical. They present scenarios designed to demonstrate that it is conceivable that a physical replica of someone can have radically different or no conscious experiences, that such an experience-less replica is possible and therefore that materialism is false. I will argue that once one understands the limitations that the physics of this world puts on cognitive systems, zombies (...) and the inverted spectrum are not conceivable. (shrink)

Proponents of the hard problem of consciousness argue that the zombie and inverted spectrum thought experiments demonstrate that consciousness cannot be physical. They present scenarios designed to demonstrate that it is conceivable that a physical replica of someone can have radically different or no conscious experiences, that such an experience-less replica is possible and therefore that materialism is false. I will argue that once one understands the limitations that the physics of this world puts on cognitive systems, zombies (...) and the inverted spectrum are not conceivable. (shrink)

Purest points of Hering's six primary colors reside at different levels of lightness such that inversion of each hue pair would be detectable in subjects' choice of foci on the Munsell array. An inverted spectrum would not impose the isomorphism constraint on a contrast of red-green or yellow-blue, whatever we conclude about inference in functionalism.

How "red", "green" were defined? Through analyzing how two children with congenitally inverted color sensations corresponding to red flags and green grass accept their grand mothers’ teaching about colors, the paper get opposite conclusions against logical empiricism. The “red” and “green” and other names of properties of objects were defined by objective physical properties (or together with behavior, such as in defining “beauty”), instead our sensations. So language directly points to things in themselves passing through sensations and presentative world. (...) It is not that things in themselves are unknowable, but that sensations and presentative world cannot be exactly described by daily language. (shrink)

This chapter examines the spectrum inversion hypothesis as an argument against certain kinds of account of what it’s like to be conscious of color. The hypothesis aims to provide a counterexample to accounts of what it’s like to be conscious of color in non-qualitative terms, as well as to accounts of what it’s like to be conscious of color in terms of the representational content of conscious visual states (which, according to some philosophers, is in turn given an account (...) in non-qualitative terms). I explain the hypothesis’s reasoning in sections 1 and 2. I then take up background issues: since the counterexample provided by the hypothesis is typically given as a possibility rather than an actuality, I briefly discuss the kind of possibility involved in section 3, and the methodologies used to evaluate the plausibility of possibilities in section 4. In section 5, I describe some general considerations that are commonly used against the spectrum inversion hypothesis. I take up attempts to support the hypothesis with findings from color science in section 6. I end with comments skeptical of both the motivation for the spectrum inversion hypothesis and the methodology used to support it. (shrink)

Scientific realists argue that a good track record of multi-agent, and multiple method, validation of empirical claims is itself evidence that those claims, at least partially and approximately, reflect ways nature actually is independent of the ways we conceptualize it. Constructivists contend that successes in validating empirical claims only suffice to establish that our ways of modelling the world, our “constructions,” are useful and adequate for beings like us. This essay presents a thought experiment in which beings like us intersubjectively (...) validate claims about properties of particular things in nature under conditions in which those beings have profoundly different personal phenomenological experiences of those properties. I submit that the thought experiment scenario parallels our actual situation, and argue that this shows that successes in intersubjectively validating empirical claims are indeed enough to claim victory for the realist. More specifically, I champion a variation of realism that marries Ronald Giere’s brand of ‘perspectival realism’ with Philip Kitcher’s ‘real realism,’ and posits that causal relations between ourselves and properties instantiated in nature ground our references to the relevant properties even though our conceptions of them are perspective relative. (shrink)

Critics of wide functionalism have traditionally sought to attack the theory by exposing weaknesses in its account of the qualitative content of experience. Wide functionalist theories of intentional content, however, were spared philosophical scrutiny. I propose that wide functionalist accounts of the intentional content are equally susceptible to attack. I will attempt to demonstrate this by enlisting the functionalist's old foe from the qualia wars - the inverted spectrum hypothesis - in a new way. If the argument is (...) sound, not only will I have shown that the inverted spectrum hypothesis may have more use than philosophical literature recognizes, I will have also exposed a weakness in a dominant philosophical theory: the wide functionalist theory of intentional content. (shrink)

Functionalism, a philosophical theory, has empirical consequences. Functionalism predicts that where systematic transformations of sensory input occur and are followed by behavioral accommodation in which normal function of the organism is restored such that the causes and effects of the subject's psychological states return to those of the period prior to the transformation, there will be a return of qualia or subjective experiences to those present prior to the transform. A transformation of this type that has long been of philosophical (...) interest is the possibility of an inverted spectrum. Hilary Putnam argues that the physical possibility of acquired spectrum inversion refutes functionalism. I argue, however, that in the absence of empirical results no a priori arguments against functionalism, such as Putnam's, can be cogent. I sketch an experimental situation which would produce acquired spectrum inversion. The mere existence of qualia inversion would constitute no refutation of functionalism; only its persistence after behavioral accommodation to the inversion would properly count against functionalism. The cumulative empirical evidence from experiments on image inversion suggests that the results of actual spectrum inversion would confirm rather than refute functionalism. (shrink)

This is terribly hard, Thouless, I'm sorry. I have thought over all this for years. … It is now as if we had ploughed furrows in different parts of a field. There is a lot left to do. Judging from their writings, most contemporary analytic philosophers have not been persuaded that “the inverted spectrum problem” is – as Wittgenstein maintained – really a conceptual puzzle calling for dissolution, rather than a straight problem calling for a solution. In this (...) paper, I present Wittgenstein's view as clearly and persuasively as I can, contrasting it with the views of Sidney Shoemaker and Ned Block, two of his more prominent critics. I conclude with a look at Frank Jackson's well-known Knowledge Argument, which, if successful, would demonstrate the futility of looking for a physicalist solution to the inverted spectrum and related philosophical problems. My goal is to combat what I take to be the common and unfortunate failure – among both physicalistically inclined philosophers, including Shoemaker and Block, and anti-physicalists, such as Jackson – to appreciate the force of Wittgenstein's arguments. (shrink)

Palmer's attempt to dust off Locke's construct of “inverted spectrum” is discussed here to examine its plausibility. Perceptual inversion could be fulfilled by adopting the notion of “inverted trichromacy” rather than by the proposed existence of “red-green reversed trichromats.” Although the former alternative conforms to a hypothetical world of vampires, it fails to conform to the realities of genetics and neuroscience.

Most philosophers who have endorsed the idea that there is such a thing as phenomenal content—content that supervenes on phenomenal character—have also endorsed what I call Standard Russellianism. According to Standard Russellianism, phenomenal content is Russellian in nature, and the properties represented by perceptual experiences are mind-independent physical properties. In agreement with Sydney Shoemaker [Shoemaker, S. (1994). Philosophy and Phenomenological Research, 54 249–314], I argue that Standard Russellianism is incompatible with the possibility of spectrum inversion without illusion. One defense (...) of (...) Standard Russellianism is to hold that spectrum inversion without illusion is conceivable but not in fact possible. I argue that this response fails. As a consequence, either phenomenal content is not Russellian, or experiences do not represent mind-independent physical properties. (shrink)

Christopher Peacocke has recently made an important and insightful effort to fashion a non-verificationist method for distinguishing sense from nonsense. The argument is subtle and complex, and varies somewhat with each of his three target ‘spurious hypotheses’: that if a perfect fission of one person into two were to occur, one and only one of the resulting persons would be identical with the original; that another person’s visual experience can be qualitatively different from your own when you are both seeing (...) the same object, even though your relevant brain states are physically identical and so are your environmental conditions; and that the entire material universe is moving undetectably at a particular uniform velocity with respect to absolute space. My own assessment of his efforts is that they are most successful against the third of these hypotheses, and that this is a function of the fact that of the three, it alone clearly employs a problematic concept- that of absolute location. However, my purpose here is not to engage in a comprehensive evaluation of Peacocke’s project; it is rather to defend the extreme inverted spectrum hypothesis against his attack. I shall argue not only that his argument against EISH fails, but that he is himself independently committed to its intelligibility. Beyond that, I shall point out some striking and, to my mind, welcome consequences of his plausible claims concerning the relations between his own proposal and certain other views concerning content theory; the consequences in question depend both on his positive proposal and on my reasons for rejecting his argument against the extreme inversion hypothesis. (shrink)

Christopher Peacocke has recently made an important and insightful effort to fashion a non-verificationist method for distinguishing sense from nonsense. The argument is subtle and complex, and varies somewhat with each of his three target ‘spurious hypotheses’: that if a perfect fission of one person into two were to occur, one and only one of the resulting persons would be identical with the original; that another person’s visual experience can be qualitatively different from your own when you are both seeing (...) the same object, even though your relevant brain states are physically identical and so are your environmental conditions; and that the entire material universe is moving undetectably at a particular uniform velocity with respect to absolute space. My own assessment of his efforts is that they are most successful against the third of these hypotheses, and that this is a function of the fact that of the three, it alone clearly employs a problematic concept- that of absolute location. However, my purpose here is not to engage in a comprehensive evaluation of Peacocke’s project; it is rather to defend the extreme inverted spectrum hypothesis against his attack. I shall argue not only that his argument against EISH fails, but that he is himself independently committed to its intelligibility. Beyond that, I shall point out some striking and, to my mind, welcome consequences of his plausible claims concerning the relations between his own proposal and certain other views concerning content theory; the consequences in question depend both on his positive proposal and on my reasons for rejecting his argument against the extreme inversion hypothesis. (shrink)

Philosophers have devoted a great deal of discussion to the question of whether an inverted spectrum thought experiment refutes functionalism. (For a review of the inverted spectrum and its many philosophical applications, see Byrne, 2004.) If Ho?man is correct the matter can be swiftly and conclusively settled, without appeal to any empirical data about color vision (or anything else). Assuming only that color experiences and functional relations can be mathematically represented, a simple mathematical result.

This study was designed to test three competing hypotheses (impaired configural processing; impaired Theory of Mind; atypical amygdala functioning) to explain the basic facial expression recognition profile of adults with autism spectrum disorders (ASD). In Experiment 1 the Ekman and Friesen (1976) series were presented upright and inverted. Individuals with ASD were significantly less accurate than controls at recognising upright facial expressions of fear, sadness and disgust and their pattern of errors suggested some configural processing difficulties. Impaired recognition (...) of inverted facial expressions suggested some additional difficulties processing the facial features. Unexpectedly, the clinical group misidentified fear as anger. In Experiment 2 feature processing of facial expressions was investigated by presenting stimuli in a piecemeal fashion, starting with either just the eyes or the mouth. Individuals with ASD were impaired at recognising fear from the eyes and disgust from the mouth; they also confused fearful eyes as being angry. The findings are discussed in terms of the three competing hypotheses tested. (shrink)

Dissociation thought experiments like Zombie and Inverted Spectrum cases play an essential role in the qualia debate. Critics have long since argued that these cases raise serious epistemic issues, undermining first person access to phenomenal states also in normal subjects. Proponents have denied this because, due to their phenomenal experience, normal subjects have epistemic abilities that Zombies don’t have. Here I will present a modified version of these thought experiments: Part-time Zombies and Part-time Inverts switch between normal and (...) abnormal states every now and then. Thus they provide insight into their epistemic situation showing that the mere possibility of Zombies and Inverts has consequences which undermine essential epistemic features of phenomenal properties even in normals. This line of reasoning will be corroborated by theoretical considerations on the epistemic requirements of phenomenal states. All this provides support for the “functional mapping hypothesis.” According to this hypothesis, any significant phenomenal difference can be mapped to a specific functional difference which is accessible from the third person perspective as well. (shrink)

This chapter contains sections titled: Abstract Relativistic Content The Argument from Primitive Colors The Argument from the Inverted Spectrum The Argument from Dual Looks The Argument from Duplication Conclusion References.

Mental states that are inherently conscious are said to be “phenomenally conscious” by philosophers. If phenomenal consciousness is a natural phenomenon, a part of the physical world, we can reasonably suppose that there should be a mechanism which provides an explanatory link between the subjective and the objective. Philosophical zombies pose a serious threat to any sort of physicalist view of phenomenal consciousness. They are microphysical duplicates that lack phenomenal consciousness. The problem of the inverted spectrum is sometimes (...) presented with respect to a single individual who adapts to an operation through time and eventually forgets that things ever looked any different to him. Not all philosophers accept that experiences are transparent. There is no one problem of unity for experiences, and there is no one kind of unity either. Split‐brain subjects, divided consciousness, and the problem of animal consciousness are also discussed. (shrink)

endorsed one kind of inverted spectrum hypothesis and rejected another. This paper argues that the kind of inverted spectrum hypothesis that Wittgenstein endorsed is the thin end of the wedge that precludes a Wittgensteinian critique of the kind of inverted spectrum hypothesis he rejected. The danger of the dangerous kind is that it provides an argument for qualia, where qualia are contents of experiential states which cannot be fully captured in natural language. I will (...) pinpoint the difference between the innocuous and dangerous scenarios that matters for the argument for qualia, give arguments in favor of the coherence and possibility of the dangerous scenario, and try to show that some standard arguments against inverted spectra are ineffective against the version of the dangerous scenario I will be advocating. The leading idea of the paper is that an argument for qualia based on spectrum inversion does not require that the inversion be behaviorally indistinguishable. At one crucial point, I will rely on a less controversial version of an argument I gave in Block. Wittgenstein's views provide a convenient starting point for a paper that is much more about qualia than about Wittgenstein. (shrink)

In a series of papers and lectures, Sydney Shoemaker has developed a sophisticated Russellian theory of phenomenal content. It has as its central motivation two considerations. One is the possibility of spectrum - inversion without illusion. The other is the transparency of experience.

Inverted spectrum and absent-qualia arguments have at least shown that giving the functional role of a qualitative state is challenging, as it is arguable that the same functional organization among one's inputs, outputs, and mental states can be preserved despite having one's qualia radically altered or eliminated. Sydney Shoemaker has proposed a promising strategy for the functionalist: defining a given qualitative state as being disposed to cause a belief that one is in such a state. Such beliefs would (...) be different or not obtain should the qualitative state be altered or absent—showing that the qualitative state is in fact functionally relevant. I will argue that this approach, and a similar one by David Chalmers, face a difficulty in accounting for qualia at a fine grain, particularly those that do not readily fit our linguistic concepts and/or occur in peripheral awareness. I then show how the problem can be solved by incorporating certain conditional statements into functional definitions of qualia, and by relying on two theoretical resources I will discuss: qualitative beliefs with nonlinguistic content and QSMs (qualia-structuring mental phenomena). (shrink)

In November 2003, the University of Fribourg hosted a symposium on the ontology of colors. The invited participants included Justin Broackes, Alex Byrne, David Chalmers, Larry Hardin, Joe Levine and Barry Maund. The points of view presented by the participants in their thought-provoking papers were highly divergent. The presentation of each paper was followed by a long and intense discussion. Despite the divergence of the views proposed, the discussion during the symposium was highly focused. Several specific issues came up repeatedly (...) in the debate and illuminated the puzzle about the nature of colors in a thought provoking way from different angles. We include these papers in our brief description in the present introduction to present to the reader all the different viewpoints that have nourished the debate throughout the symposium. We are glad to be able to include one further invited paper by Jonathan Cohen in the present volume. In an attempt to transfer some of the atmosphere of the meeting to the reader and in order to make this collection still more stimulating we invited each participant to contribute comments on the other papers. (shrink)

This paper advances the thesis that sensory concepts have as a semantic component the first-person indexical. It is argued that the private nature of our access to our own sensations forces, in our talking about them, an indexical reference to the inner states of the speaker in lieu of publicly accessible properties by which reference is usually fixed. Indexicals, such as ‘here’, can be understood despite ignorance of their referent. Such is the case with sensory terms. Furthermore, the thesis that (...) sensory terms are indexical has considerable explanatory power. I give two examples: firstly, I argue that clashes of intuition over Block's ‘inverted spectrum’ thought experiment can be explained by appeal to semantic properties of indexicals. Secondly, I argue that multiple realisability intuitions can be shown to be consistent with the view that sensations are type-identical with brain states. (shrink)

I argue that the inverted spectrum hypothesis is nota possibility we should take seriously. The principlereason is that if someone's qualia were inverted inthe specified manner there is reason to believe thephenomenal difference would manifest itself inbehaviour. This is so for two reasons. First, Isuggest that qualia, including phenomenal colours, arepartly constituted by an affective component whichwould be inverted along with the connected qualia. Theresulting affective inversions will, given theintimate connections that exist between emotions andbehaviour, likely (...) manifest themselves in behaviour, inwhich case the underlying phenomenal differences canbe functionally captured. Second, I argue that othersense modalities lack the structural featuresnecessary for undetectable inversion which, because oftheir analogy with colour qualia, weakens theplausibility of such an inversion in the original caseof vision. (shrink)

Following the well known inverted spectrum argument by John Locke we examine the necessity of the first person experience in creating scientific knowledge, in particular, in physics. It is found that Locke’s argument is irrelevant for creating objective knowledge as the necessary things we need to do physics are: ability to perform measurements in terms of comparing certain quantities, ability to create theoretical ideas (in dependence inter alia on cultural principles, changing in the course of history), and the (...) brain structure enabling the former two. (shrink)

Susan Hurley has attacked the ''Duplication Assumption'', the assumption thatcreatures with exactly the same internal states could function exactly alike inenvironments that are systematically distorted. She argues that the dynamicalinterdependence of action and perception is highly problematic for the DuplicationAssumption when it involves spatial states and capacities, whereas no such problemsarise when it involves color states and capacities. I will try to establish that theDuplication Assumption makes even less sense for lightness than for some ofthe spatial cases. This is due (...) not only to motor factors, but to the basic physicalasymmetry between black and white. I then argue that the case can be extendedfrom lightness perception to hue perception. Overall, the aims of this paper are:(1) to extend Susan Hurley''s critique of the Duplication Assumption; (2) to argueagainst highly constrained versions of Inverted Spectrum arguments; (3) to proposea broader conception of the vehicle for color perception. (shrink)

In the “Notes for Lectures on “Private Experience‘ and “Sense Data‘", Wittgenstein endorsed one kind of inverted spectrum hypothesis and rejected another. This paper argues that the kind of inverted spectrum hypothesis that Wittgenstein endorsed is the thin end of the wedge that precludes a Wittgensteinian critique of the kind of inverted spectrum hypothesis he rejected. I will attempt to explicate the difference between the innocuous and dangerous scenarios, to give arguments in favor of (...) the coherence of the dangerous scenario, and to show that the standard arguments to the effect that the dangerous scenario is impossible are flawed or ineffective against the version of the dangerous scenario whose coherence I will be advocating. I will also agree with what I think is Wittgenstein’s position that the kind of inverted spectrum hypothesis he rejected lets qualia in the door, where qualia are qualities of experiential states whose phenomenal character cannot be expressed in natural language. Further, I will argue that acknowledging the coherence of the innocuous inverted spectrum commits Wittgenstein to the coherence of the dangerous inverted spectrum, thereby undermining Wittgenstein’s deepest views about the mind. In other work, I have used the inverted spectrum hypothesis as an argument against functionalism and representationism, but here the focus is on its role in arguing for the possibility of qualia. (shrink)