The Inverted Spectrum

What, according to Locke, are ideas? I argue that Locke does not give an account of the nature of ideas. In the Essay, the question is simply set to one side, as recommended by the “Historical, plain Method” that Locke employs. This is exemplified by his characterization of ‘ideas’ in E I.i.8, and the discussion of the inverted spectrum hypothesis in E II.xxxii. In this respect, Locke's attitude towards the nature of ideas in the Essay is reminiscent of Boyle's diffident (...) attitude towards the nature of matter. In posthumously published work, however, Locke suggests that the enquiry into the nature of ideas is one of the things that the enquiry into the extent of human knowledge undertaken in the Essay actually shows to lie beyond the “compass of human understanding”. In this respect, Locke's attitude towards the nature of ideas is reminiscent of Sydenham's attitude towards the nature of diseases. (shrink)

Kulvicki’s goal is to give a representationalist account of what it’s like to see a property that is “fully externalist about perceptual representation” (p. 1) and yet accommodates a certain “internalist intuition” (p. 4), which he describes as follows: “something about what it is like to see a property is internally determined, dependent only on the way one is built from the skin in” (p. 3). He illustrates this intuition with an inverted spectrum case and the manifest-image problem. On his (...) view, there’s an apparent conflict between the intuition and representationalism. That’s because, on representationalism, “what it is like to see a shade of color can be exhaustively explained in terms of what is perceptually represented” (p. 1) and, he claims, “all representational facts are externally determined” (p. 4). In short, if what it’s like is partly internally determined, then how can it be fully explained in terms of externally determined representational facts? (shrink)

We give a plausible-sounding conjecture involving the number of n-equivalence classes of structures of size m which would imply that the complement of a spectrum is also a spectrum.

This paper revisits some classic thought experiments in which experiences are detached from their characteristic causal roles, and explores what these thought experiments tell us about qualia epiphenomenalism, i.e. the view that qualia are epiphenomenal properties. It argues that qualia epiphenomenalism is true just in case it is (nomologically) possible for experiences of the same type to have entirely different causal powers. This is done with the help of new conceptual tools regarding the concept of an epiphenomenal property. One conclusion (...) is that it is not obvious if qualia epiphenomenalism is false; and it is also not obvious what should make us believe that it is false---or for that matter, true. Connections between qualia epiphenomenalism, physicalism and nonphysicalist property dualism are further explored. (shrink)

The claim that behaviourally undetectable inverted spectra are possible has been endorsed by many physicalists. I explain why this starting point rules out standard forms of scientific explanation for qualia. The modern ‘phenomenal concept strategy’ is an updated way of defending problematic intuitions like these, but I show that it cannot help to recover standard scientific explanation. I argue that Chalmers is right: we should accept the falsity of physicalism if we accept this problematic starting point. I further argue that (...) accepting this starting point amounts to at least implicitly endorsing certain theoretical claims about the nature of introspection. I therefore suggest that we allow ourselves to be guided, in our quest to understand qualia, by whatever independently plausible theories of introspection we have. I propose that we adopt a more moderate definition of qualia, as those introspectible properties which cannot be fully specified simply by specifying the non-controversially introspectible ‘propositional attitude’ mental states (including seeing x, experiencing x, and so on, where x is a specification of a potentially public state of affairs). Qualia thus defined may well fit plausible, naturalisable accounts of introspection. If so, such accounts have the potential to explain, rather than explain away, the problematic intuitions discussed earlier; an approach that should allow integration of our understanding of qualia with the rest of science. (shrink)

It has been suggested that difficult-to-quantify differences in visual processing may prevent researchers from equating the color experience of different observers. However, spectral locations of unique hues are remarkably invariant with respect to everything other than gross differences in preretinal and photoreceptor absorptions. This suggests a stereotyping of neural color processing and leads us to posit that minor differences in observer neurophysiology may be irrelevant to color experience.

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)

There is reason to believe that people of different gender, race or age differ in spectra that are shifted relative to one another. Shifted spectra are not as dramatic as inverted spectra, but they can be used to make some of the same philosophical points.

Physicalism is incompatible with what is known as the possibility of zombies, that is, the possibility of a world physically like ours, but in which there are no conscious experiences. But it is compatible with what is known as the possibility of ghosts, that is, the possibility of a world which is physically like ours, but in which there are additional nonphysical entities. In this paper we argue that a revision to the traditional definition of physicalism designed to accommodate the (...) possibility of ghosts inadvertently accommodates what is known as the possibility of inverted spectra, that is, the possibility of a world which is physically like ours, but in which colour experience is inverted. This consequence is unwelcome, because it is widely agreed that the possibility of inverted spectra is incompatible with physicalism. We argue for a revised definition of physicalism which resolves this problem. We then use our definition to argue that physicalism is not compatible with what is known as the possibility of blockers, that is, the possibility of a world which is physically like ours, but in which additional nonphysical entities have prevented the existence of conscious experience. This undermines Stephan Leuenberger's attempt to defend physicalism from arguments which purport to establish the possibility of zombies. (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)

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)

Intentionalism debates seek to uncover the relationship between the qualitative aspects of experience—phenomenal character—and the intentionality of the mind. They have been at or near center stage in the philosophy of mind for more than two decades, and in my view need to be reexamined. There are two core distinct intentionalism debates that are rarely distinguished (Sect. 1). Additionally, the characterization of spectrum inversion as involving inverted qualities and constant intentional content is mistaken (Sect. 3). These confusions can be witnessed (...) from an often-ignored and lonely perspective, that of the sense-datum theorist, and in particular of the projectivist (Sect. 2). In my view we have been so wary of sense-datum theory in recent years that we have failed to see that, even if false, it may permit perspectives on intentionalism issues difficult to occupy from other views. (shrink)

As Gert says, the basic claim of representationism is that the phenomenal character of an experience supervenes on its representational content. Restricted to color experience, representationism may be put as follows.

Qualia inversion thought experiments are ubiquitous in contemporary philosophy of mind. The most popular kind is one or another variant of Locke's hypothetical case of.

Palmer's subjectivity barrier seems to be erected on a popular but highly suspect conception of visual experience, and his color room argument is invalid.

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 admirable volume of readings is the first of a pair: the editors are to be applauded for placing the philosophy of color exactly where it should go, in ...

Qualia internalism is the thesis that qualia are intrinsic to their subjects: the experiences of intrinsic duplicates have the same qualia. Content externalism is the thesis that mental representation is an extrinsic matter, partly depending on what happens outside the head. 1 Intentionalism comes in strong and weak forms. In its weakest formulation, it is the thesis that representationally identical experiences of subjects have the same qualia. 2.

Philosophers who advocate the possibility of spectrum inversion often conclude that the qualitative content of experiential states pose a serious problem for functionalism. I argue that in order for the inversion hypothesis to support this conclusion one needs to show that it generalizes to all species of qualia. By examining features of touch, taste, and olfactory sensations, I show there is good reason to resist this generalization, in which case appeals to the possibility of spectral inversion are considerably less effective (...) than they may initially appear. (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)

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)

Spectrum inversion is a thought experiment, and I would wager that there is no better diagnostic test to the disciplinary affiliation of a randomly selected member of the audience than your reaction to a thought experiment. It is a litmus test. If you find that you are paying close attention, subvocalizing objections, and that your heart-rate and metabolism go up, you have turned pink: you are a philosopher. If on the other hand the thought experiment leaves you cold, and you (...) wonder why otherwise sensible people would worry about such things, you have turned blue and you are a psychologist. (shrink)

Subjectivists hold that you cannot specify color kinds without implicitly or explicitly referring to the dispositions of observers. Even though "yellow" is ascribed to physical items, and presumably there is something physical in each such item causing it to be so characterized, the only physical similarity between all such items is that they all affect an observer in the same way. So the principles organizing the colors are all found within the skin.

The possibility that what looks red to me may look green to you has traditionally been known as "spectrum inversion." This possibility is thought to create difficulties for any attempt to define mental states in terms of behavioral dispositions or functional roles. If spectrum inversion is possible, then it seems that two perceptual states may have identical functional antecedents and effects yet differ in their qualitative content. In that case the qualitative character of the states could not be functionally defined.

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)

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)

Owen Flanagan's arguments concerning qualia constitute an intermediate position between Dennett's “disqualification” of qualia and the thesis that qualia represent an insurmountable obstacle to constructive naturalism. This middle ground is potentially attractive, but it is shown to have serious problems. This is brought out via consideration of several classic areas of dispute connected with qualia, including the inverted spectrum, Frank Jackson's thought experiment, Hindsight, and epiphenomenalism. An attempt is made to formulate the basis for a less vulnerable variant on the (...) “middle ground”. (shrink)

Funkcinës psichiniø savybiø analizës atveriama jø materialiojo ákûnijimo ávairovës galimybë verèia materialistiná monizmà sàmonës filosofijoje formuluoti ne psichiniø ir fiziniø savybiø tapatumo, bet pirmøjø pareities nuo antrøjø tezæ. Pareities sàvoka sàmonës filosofijoje iðreiðkia minimalius reikalavimus fizikalistinëms teorijoms – paneigus pareities fizikalizmà bûtø paneigtos ir stipresnës fizikalizmoversijos. Straipsnyje tyrinëjama fizikalizmo kritika paremta vadinamuoju kokybiø perkeitimo galimybës argumentu. Parodoma, kad, viena vertus, toks argumentas negali bûti atremtas nuorodomis áempirinius duomenis, nes svarstoma hipotetinë situacija numano jos empiriná nestebimumà; kita vertus, jei svarstoma situacija (...) ið tikrøjø yra galima, tai kokybinës psichinës charakteristikos niekaip nërasusaistytos funkciðkai ar fiziologiðkai apraðomais ryðiais, vadinasi, antireduktyvistinæ iðvadà galima grástisvarstant ne tik atvejus, kai kokybës perkeistos, bet ir kai jø apskritai nëra.Pagrindiniai þodþiai: sàmonës filosofija, fizikalizmas, funkcionalizmas, pareitis, perkeistos kokybës. (shrink)

As a lefthanded person, I can wonder whether I am a left-hemisphere-dominant speaker or a right-hemisphere-dominant speaker or something mixed, and the only way I can learn the truth is by submitting myself to objective, Athird-person@ testing. I don =t Ahave access to @ this intimate fact about how my own mind does its work. It escapes all my attempts at introspective detection, and might, for all I know, shunt back and forth every few seconds without my being any the (...) wiser. In striking contrast to this is the traditional idea that there are. (shrink)

Philosophers have adopted various names for the things in the beholder that have been supposed to provide a safe home for the colors and the rest of the properties that have been banished from the "external" world by the triumphs of physics: "raw feels", "sensa", "phenomenal qualities" "intrinsic properties of conscious experiences" "the qualitative content of mental states" and, of course, " qualia," the term I will use. There are subtle differences in how these terms have been defined, but I'm (...) going to ride roughshod over them. I deny that there are. (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)