Physicalist Theories of Color

This article cohesively discusses three topics, namely color and its perception, the yet-to-be-solved hard problem of consciousness, and the theoretical possibility of strong AI. First, the article restores color back into the physical world by giving cross-species evidence. Secondly, the article proposes a dual-field with function Q hypothesis (DFFQ) which might explain the ‘first-person point of view’ and so the hard problem of consciousness. Finally, the article discusses what DFFQ might bring to artificial intelligence and how it might allow strong (...) AI to stay true. (shrink)

The circularity problem states that the representationalist about phenomenal consciousness gives a circular explanation if she adopts the classic view about secondary qualities, such as colours, that characterises them as dispositions to produce experiences with a specifi c phenomenal character. Since colour primitivism faces severe diffi culties, it seems that colour physicalism is the only viable option for the representationalist. I will argue that the representationalist is not committed to colour physicalism because she can adopt an anti-realist theory of colour. (...) My diagnosis is that the alleged commitment to colour physicalism rests upon the acceptance of colour realism which is due to the approval of externalist versions of representationalism, such as tracking representationalism. I will argue that the representationalist can deal with the circularity problem by adopting figurative projectivism, which holds that colours are contingently non-instantiated properties that only figure in the representational contents of colour experiences. (shrink)

The study of color expanded rapidly in the 20th century. With this expansion came fragmentation, as philosophers, physicists, physiologists, psychologists, and others explored the subject in vastly different ways. There are at least two ways in which the study of color became contentious. The first was with regard to the definitional question: what is color? The second was with the location question: are colors inside the head or out in the world? In this chapter, we summarize the most prominent answers (...) that color scientists and philosophers gave to the definitional and location questions in the 20th century. We identify some of the different points at which their work intersected, as well as the most prominent schisms between them. One overarching theme of the chapter is the surprising proliferation of different views on color. Whereas some assume that progress in science must take the form of convergence, the 20th century history of color exhibited a marked divergence in views. This chapter leaves it an open question whether an ultimate unification of views is possible, or whether the only thing that ties together the study of “color” is the shared inheritance of a word. (shrink)

A survey of arguments for and against the view that colors are physical properties.

There is variation in how people perceive colors and other secondary qualities. The challenge of perceptual variation is to say whose perceptions are accurate. According to Sextus, Protagoras’ response is that all of our perceptions might be accurate. As this response is traditionally developed, it is difficult to explain color illusion and color constancy. This difficulty is due to a widespread assumption called perceptual atomism. This chapter argues that, if we want to develop Protagoras’ response, we need to give up (...) perceptual atomism. It ends with a brief sketch of an alternative called perceptual structuralism. (shrink)

I argue that phenomenal externalism is preferable to phenomenal internalism on the basis of externalism's explanatory power with respect to qualitative character. I argue that external qualities, namely, external physical properties that are qualitative independent of consciousness, are necessary to explain qualitative character, and that phenomenal externalism is best understood as accepting external qualities while phenomenal internalism is best understood as rejecting them. I build support for the claim that external qualities are necessary to explain qualitative character on the basis (...) of a model of color perception as a certain sort of information filter by which perceivers gain access to external qualities. (shrink)

Nat Hansen builds a new argument for subjectivism about the semantics of color language, based on a potential kind of intersubjective disagreements about comparative color statements. In reply, I note that the disagreements of this kind are merely hypothetical, probably few if actual, and not evidently relevant as test cases for a semantic theory. Furthermore, even if they turned out to be actual and semantically relevant, they would be intuitively unusable by the subjectivist.

Externalist representationalists claim that the phenomenal character of a visual perceptual experience is determined by the representational content of that experience. Their deployment of the idea that perceptual experience is transparent shows that they account for representational content with reference to the properties which are represented – the properties out there in the world. I explain why this commits the externalist representationalist to objectivism and realism about colour properties. Colour physicalism has proved to be the position of choice for externalist (...) representationalists. However, my aim in this paper is to demonstrate that the proponent of the view which combines externalist representationalism with colour physicalism is unable to account for the phenomenal character of colour hallucination. (shrink)

I describe a new, comparative, version of the argument from interpersonal variation to subjectivism about color. The comparative version undermines a recent objectivist response to standard versions of that argument.

An important challenge to color objectivists, who hold that statements concerning color are made true or false by objective facts, is the argument from interpersonal variation in where normal observers locate the unique hues. Recently, an attractive objectivist response to the argument has been proposed that draws on the semantics of gradable adjectives and which does not require defending the idea that there is a single correct location for each of the unique hues Noûs 50: 3–40),. In ), I argued (...) that the recent objectivist response doesn’t apply to comparative occurrences of color adjectives, so a revised, comparative, version of the argument from interpersonal variation remains a powerful objection to certain types of objectivism. In this paper, I address several unsatisfactory objectivist replies to the comparative version of the argument from interpersonal variation, and offer what I think is a more plausible objectivist reply to the comparative argument from interpersonal variation. (shrink)

The early modern distinction between primary and secondary qualities continues to have a significant impact on the debate about the nature of color. An aspect of this distinction that is still influential is the idea that the mind-independence of color requires that it is a primary quality. Thus, using shape as a paradigm example of a primary quality, a longstanding strategy for determining whether color is mind-independent is to consider whether it is sufficiently similar to shape to be a primary (...) quality. However, I’ll argue that the idea that the mind-independence of color requires that it is a primary quality is mistaken, and that, to the contrary, while color is not a primary quality, it is mind-independent. I’ll propose an alternative understanding of what the mind-independence of color requires. This alternative models color perception on an information filter. According to this model, mental qualities that I’ll call media qualities are involved in color perception. The involvement of mental qualities suggests mind-independence. However, I’ll argue, their involvement is modeled after the qualities of a kind of filter that provides access to, but does not constitute, filtered qualities. (shrink)

I offer a new objectivist theory of the contents of color language and color experience, intended especially as an account of what normal intersubjective variation in color perception and classification shows about those contents. First I explain an abstract account of the contents of color and other gradable adjectives; on the account, these contents are certain objective properties constituted in part by contextually intended standards of application, which are in turn values in the dimensions of variation associated with the adjectives. (...) Then I propose an explanation of normal variations in linguistic color classification; these are postulated to be effects of differences in intended standards for the color adjectives appearing in the classifying predicates. Next, I consider a potential objection to this explanation, based on the suggestion that contextual content should be more accessible than the explanation predicts. In reply, I point out that contextual content is occasionally opaque to unsophisticated reflection. Finally, I present a companion account of the contents of color experiences on which these represent an object as lying on certain salient intervals in the chromatic dimensions, and I show how the account accommodates intersubjective variation in color perception. (shrink)

It is widely agreed that properties play causal roles: they capture the causal powers of things. But do properties have their causal roles essentially? David Lewis did not think so. He adhered to the doctrine of quidditism, namely the doctrine that the identity of properties is primitive and that they can trade their causal roles. Quidditism is controversial. But Lewis did not see why he should want to reject it. He knew that he could avoid quidditism on the cheap by (...) treating individuals and properties alike in rejecting transworld multilocation of properties and endorsing a counterpart theory for properties. But he did not see why he should want to do so. In this article, I argue that Lewis should have wanted to endorse a counterpart theory for properties in order to reject quidditism. My argument concerns resemblance relations among properties. Another constitutive role of properties is that they capture objective resemblances between their instances. The premises of my argument are intuitive claims about resemblances among some properties that Lewis held on Humean grounds. (shrink)

Color relationalism holds that the colors are constituted by relations to subjects. The introspective rejoinder against this view claims that it is opposed to our phenomenally-informed, pre-theoretic intuitions. The rejoinder seems to be correct about how colors appear when looking at how participants respond to an item about the metaphysical nature of color but not when looking at an item about the ascription of colors. The present article expands the properties investigated to sound and taste and inspects the mentioned asymmetry, (...) with a particular focus on the principle of charity. Using a metaphysical item, we find that color and sound are no different from shape, our control for a clearly anti-relational property. Taste, on the other hand, is no different from likability, our control for a clearly relational property. Importantly, we find that the disparity between metaphysical and ascription items is due to participants using a principle of charity to interpret disagreement cases such that both parties can be correct. (shrink)

Colours appear to instantiate a number of structural properties: for instance, they stand in distinctive relations of similarity and difference, and admit of a fundamental distinction into unique and binary. Accounting for these structural properties is often taken to present a serious problem for physicalist theories of colour. This paper argues that a prominent attempt by Byrne and Hilbert to account for the structural properties of the colours, consistent with the claim that colours are types of surface spectral reflectance, is (...) unsuccessful. Instead, it is suggested that a better account of the structural properties of the colours is provided by a form of non-reductive physicalism about colour: a naïve realist theory of colour, according to which colours are superficial mind-independent properties. (shrink)

This paper presents a new response to the colour similarity argument, an argument that many people take to pose the greatest threat to colour physicalism. The colour similarity argument assumes that if colour physicalism is true, then colour similarities should be scrutable under standard physical descriptions of surface reflectance properties such as their spectral reflectance curves. Given this assumption, our evident failure to find such similarities at the reducing level seemingly proves fatal to colour physicalism. I argue that we should (...) dispense with this assumption, and thus endorse the inscrutability of colour similarity. This strategy is inspired by parallels between the colour similarity argument and the explanatory gap between mind and body made vivid by Jackson’s (1986) knowledge argument, and in particular by type-B physicalist responses to that argument. This inscrutability response is further motivated by cases in chemistry and biochemistry in which analogous scrutability theses fail to hold. Along the way, I present a challenge to standard formulations of the colour similarity argument based on the extreme context sensitivity of the similarity relation. Most presentations of the argument fail to control for such contextual variation, which raises the distinct possibility that the argument equivocates on the similarity relation across its premises. Although ultimately inconclusive, this context challenge forces a significant reformulation of the colour similarity argument, and highlights the need for much greater care in handling claims about colour similarity. (shrink)

The view that physical objects do not, in fact, possess colour properties is certainly the dominant position amongst scientists working on colour vision. It is also a reasonably popular view amongst philosophers. However, the recent philosophical debate about the metaphysical status of colour properties seems to have taken a more realist turn. In this article, I review the main philosophical views – eliminativism, physicalism, dispositionalism and primitivism – and describe the problems they face. I also examine how these views have (...) been classified and suggest that there may be less disparity between some of these positions than previously thought. (shrink)

Navigating the ontology of color used to be a simple affair. There was the naive view that colors really are in objects the way they appear, and the view that they are secondary qualities to cause certain experiences in us. Today, there are myriad well-developed views but no satisfactory taxonomy of philosophical theories on color. In this article, I first examine the two newest taxonomies on offer and argue that they are inadequate. In particular, I look at Brogaard’s taxonomy and (...) then Cohen’s. One of the reasons I am displeased with Brogaard and Cohen’s taxonomies is that I find it implausible that dispositions are relational properties. I provide an argument against this way of classifying dispositions. Having learned from the vices and virtues of Brogaard and Cohens’ taxonomies, I provide what I believe is a much-enhanced way of taxonomizing philosophical views on color. My taxonomy rules out certain views, clarifies others, and shows that there is an unnoticed view worthy of consideration. (shrink)

Relationalism is a view popularized by Cohen according to which the colors are relational properties. Cohen’s view has the unintuitive consequence that the following propositions are false: (i) no object can be more than one determinate or determinable color all over at the same time; (ii) ordinary illusion cases occur whenever the color perceptually represented conflicts, according to (i) above, with the object’s real color; and (iii) the colors we perceive obey (i). I investigate Cohen’s attempt to address these intuitive (...) propositions with which his view struggles and find it to be incompatible with how he motivates his view. (shrink)

Colour relationalism holds that the colours are constituted by relations to subjects. Anti-relationalists have claimed that this view stands in stark contrast to our phenomenally-informed, pre-theoretic intuitions. Is this claim right? Cohen and Nichols’ recent empirical study suggests not, as about half of their participants seemed to be relationalists about colour. Despite Cohen and Nichols’ study, we think that the anti-relationalist’s claim is correct. We explain why there are good reasons to suspect that Cohen and Nichols’ experimental design skewed their (...) results in favour of relationalism. We then run an improved study and find that most of our participants seem to be anti-relationalists. We find some other interesting things too. Our results suggest that the majority of ordinary people find it no less intuitive that colours are objective than that shapes are objective. We also find some evidence that when those with little philosophical training are asked about the colours of objects, their intuitions about colour and shape cases are similar, but when asked about people’s colour ascriptions, their intuitions about colour and shape cases differ. (shrink)

[This download contains the Table of Contents and Chapter 1]. I argue here that the claim that conscious states are private, in the sense that only one person can ever experience them directly, is false. There actually is a way to connect the brains of two people that would allow one to have direct experience of the other's conscious, e.g., perceptual states. This would allow, for instance, one person to see that the other had deviant color perception (which was masked (...) by correct linguistic practice). This could be achieved by connecting one person's set of executive processes (or cognitive control network) to the conscious perceptual states of the other. Chapter 5 contains an internalist physicalist account of color according to which colors exist only as brain states. Their function is to enable more precise causal interactions between the executive processes and the brain's perceptual systems. This in turn allows for more precise action: I can select the red apples and leave the green ones. (shrink)

Objectivism and projectivism are standardly taken to be incompatible theories of color. Here we argue that this incompatibility is only apparent: objectivism and projectivism, properly articulated so as to deal with basic objections, are in fundamental agreement about the ontology of color and the phenomenology of color perception.

An exposition of Kripke's unpublished critique of dispositionalism about color, followed by a review of some recent defenses of dispositionalism and a sketch of some objections that could be made to these defenses from a broadly Kripkean perspective.

One prominent ambition of theories of colour is to pay full justice to how colours are subjectively given to us; and another to reconcile this first-personal perspective on colours with the third-personal one of the natural sciences. The goal of this article is to question whether we can satisfy the second ambition on the assumption that the first should and can be met. I aim to defend a negative answer to this question by arguing that the various kinds of experienced (...) colour resemblances – notably similarities in hue distance, sameness in superdeterminables, and colour resemblances between surfaces, volumes and illuminants – cannot be accounted for in terms of the mental representa-tion of the scientifically studied properties, which colours are best identified with in response to the second ambition. (shrink)

Colour is, according to prevailing orthodoxy in perceptual psychology, a kind of autonomous and unitary attribute. It is regarded as unitary or homogeneous by assuming that its core properties do not depend on the type of ‘perceptual object’ to which it pertains and that‘colour per se’ constitutes a natural attribute in the functional architecture of the perceptual system. It is regarded as autonomous by assuming that it can be studied in isolation of other perceptual attributes. These assumptions also provide the (...) pillars for the technical field of colorimetry, and have proved very fruitful for neurophysiological investigations into peripheral colour coding. They also have become, in a technology-driven cultural process of abstraction, part of our common-sense conception of colour. With respect to perception theory, however, both assumptions are grossly inadequate, on both empirical and theoretical grounds. All the same, the idea of an internal homogeneous and autonomous attribute of ‘colour per se’, mostly taken not as an empirical hypothesis but as a kind of truism, became a guiding idea in perceptual psychology. Here, it has impeded the identification of relevant theoretical issues and consequently has become detrimental for the development of explanatory frameworks for the role of ‘colour’ within the structure of our perceptual system. The chapter argues that enquiries into colour perception cannot be divorced from general enquiries into the structure of the conceptual forms underlying perception. (shrink)

In this paper I argue that all transparent objects are colorless. This thesis is important for at least three reasons. First, if transparent objects are colorless, there is no need to distinguish between colors which characterize three-dimensional bodies, like transparent colors, and colors which lie on the surface of objects. Second, traditional objections against color physicalism relying on transparent colors are rendered moot. Finally, an improved understanding of the relations between colors, light and transparency is provided.

I propose a strategy for a metaphysical reduction of perceived color, that is, an identification of perceived color with properties characterizable in non-qualitative terms. According to this strategy, a description of visual experience of color, which incorporates a description of the appearance of color, is a reference-fixing description. This strategy both takes color appearance seriously in its primary epistemic role and avoids rendering color as metaphysically mysterious. I’ll also argue that given this strategy, a plausible account of perceived color claims (...) that colors are physical properties of physical objects. (shrink)

Color provides an instance of a general puzzle about how to reconcile the picture of the world given to us by our ordinary experience with the picture of the world given to us by our best theoretical accounts. The Red and the Real offers a new approach to such longstanding philosophical puzzles about what colors are and how they fit into nature. It is responsive to a broad range of constraints --- both the ordinary constraints of color experience and the (...) more theoretical constraints of color science, psychology, semantics, and ontology. (shrink)

Farben sind für uns sowohl objektive, als auch phänomenale Eigenschaften. In seinem Buch argumentiert Fabian Dorsch, daß keine ontologische Theorie der Farben diesen beiden Seiten unseres Farbbegriffes gerecht werden k ann. Statt dessen sollten wir akzeptieren, daß letzterer sich auf zwei verschiedene Arten von Eigenschaften bezieht: die repräsentierten Reflektanzeigenschaften von Gegenständen und die qualitativen Eigenschaften unserer Farbwahrnehmungen, die als sinnliche Gegebenheitsweisen ersterer fungieren. Die Natur der Farben gibt einen detaillierten Überblick über die zeitgenössischen philosophischen und naturwissenschaftlichen Theorien der Farben und (...) bietet sich aufgrund seines systematischen und umfassenden Charakters auch als ein seminar- oder vorlesungsbegleitendes Textbuch an. (shrink)

When objects are illuminated, the light they reflect does not simply bounce off their surface. Rather, that light is entirely reabsorbed and then reemitted, as the result of a complex microphysical event near the surface of the object. If we are to be physicalists regarding color, then we should analyze colors in terms of that event, just as we analyze heat in terms of molecular motion, and sound in terms of vibrations. On this account, colors are not standing properties of (...) objects, but events, or (more cautiously) properties associated with events. Accordingly, objects in the dark are no more colored than a turned-off stove is hot. Such an account requires rejecting some of what folk ordinarily say about color, but this is the most coherent version of color physicalism. (shrink)

I defend externalism about color experiences and color thoughts, which I argue color objectivism requires. Externalists face the following question: would a subject’s wearing inverting lenses eventually change the color content of, for instance, those visual experiences the subject reports with “red”? From the work of Ned Block, David Velleman, Paul Boghossian, Michael Tye, and Fiona Macpherson, I extract problems facing those who answer “Yes” and problems facing those who answer “No.” I show how these problems can be overcome, leaving (...) externalism available to the color objectivist. (shrink)

Many philosophers have been attracted by the view that colors are mind-independent properties of object surfaces. While this view has come in for a fair bit of criticism for failing to do justice to the facts about perceptual variation, Byrne and Hilbert have recently argued that perceptual variation involving color is no more problematic for physicalism about color than representational variation involving temperature is for physicalism about temperature. Unfortunately, the analogy on which this response rests is no less controversial than (...) the disputed view about color, and so the response leads to a standoff rather than a resolution of the debate. However, we can appeal to facts about our inferential treatment of color and other properties as a way of resolving this impasse; doing so gives us defeasible reason for rejecting the Byrne and Hilbert response, and so for rejecting their mind-independent conception of color. (shrink)

Realists about color, be they dispositionalists or physicalists, agree on the truth of the following claim: (R) x is red iff x is disposed to look red under standard conditions. The disagreement is only about whether to identify the colors with the relevant dispositions, or with their categorical bases. This is a question about the representational content of color experience: What kind of properties do color experiences ascribe to objects? It has been argued (for instance by Boghossian and Velleman, 1991) (...) that truths like (R) cannot be used in an account of the colors as they would result in ‚circular’, and therefore empty, contents. It has also been argued (for instance by Harman, 1996) that switching to an account of color in terms of a functional account of color sensations would result in a circular, and therefore empty, account. In this paper, I defend a realist account of color in terms of a (non-reductive) functional account of color sensations. Such an account of sensations has been suggested by Pagin (2000), and it can be applied to color sensations without the resulting account of the colors themselves being circular or empty. I argue that the so-called transparency of experience does not provide any argument against such an account. I also argue that on such an account, the issue of physicalism vs. dispositionalism boils down to the question of the modal profile of the color concepts. (shrink)

This paper argues for the reality of qualia as aspects of phenomenal experience. The argument focuses on color vision and develops a dispositionalist, subjectivist account of what it is for an object to be colored. I consider objections to dispositionalism on epistemological, metaphysical, and 'ordinary' grounds. I distinguish my representative realism from sense-data theories and from recent 'representational' or 'intentional' theories, and I argue that there is no good reason to adopt a physicalist stance that denies the reality of qualia (...) as phenomenally available intentional contents in Brentano's original sense of 'intentionality'. (shrink)

An adequate ontology of color must face the empirical facts about per- ceptual variation. In this paper I begin by reviewing a range of data about perceptual variation, and showing how they tell against color physicalism and motivate color relationalism. Next I consider a series of objections to the argument from perceptual variation, and argue that they are un- persuasive. My conclusion will be that the argument remains a powerful obstacle for color physicalism, and a powerful reason to believe in (...) color relationalism instead. (shrink)

(Tye 2006) presents us with the following scenario: John and Jane are both stan- dard human visual perceivers (according to the Ishihara test or the Farnsworth test, for example) viewing the same surface of Munsell chip 527 in standard conditions of visual observation. The surface of the chip looks “true blue” to John (i.e., it looks blue not tinged with any other colour to John), and blue tinged with green to Jane.¹ Tye then in effect poses a multiple choice question.

Most objectivist and dispositionalist theories of color have tried to resolve the challenge raised by color variations by drawing a distinction between real and apparent colors. This paper considers such a strategy to be fundamentally erroneous. The high degree of variability of colors constitutes a crucial feature of colors and color perception; it cannot be avoided without leaving aside the real nature of color. The objectivist theory of color defended in this paper holds that objects have locally many different objective (...) colors. Most color variations are then real and result from the extreme richness of color properties. (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)

Larry Hardin has been the most steadfast and influential critic of physicalist theories of color over the last 20 years. In their modern form these theories originated with the work of Smart and Armstrong in the 1960s and 1970s1 and Hardin appropriately concentrated on their views in his initial critique of physicalism.2 In his most recent contribution to this project3 he attacks Michael Tye’s recent attempts to defend and extend color physicalism.4 Like Byrne and Hilbert5, Tye identifies color with the (...) reflecting properties of objects (“reflectance physicalism”). Specifically, the determinate and determinable colors are identified with types of reflectances. (Setting some complications aside, the reflectance of an object is the proportion of light that it reflects at each wavelength in the visible spectrum.) These reflectance types are, in the terminology of Hilbert, anthropocentric—in the terminology of Lewis6, they are not very “natural”. (shrink)

The question of the constituting nature of colour is largely open. The old dispute between colour objectivism and colour subjectivism is still relevant. The former has defended itself against accusations of not being able to explain colour structures, while the latter view has received criticism for not being able to provide a plausible theory of the location of colours. By weakening the notion of physical categories, making some of them perceiver-depended, colour objectivists have managed to overcome at least some of (...) the previous accusations. However, the arguments based on Crane’s and Piantanida’s findings of the existence of binary colours like greenish-red and yellowish-blue, indicate the inadequacy of colour objectivism. Consequently, we have colours but our theories of them are false. (shrink)

Byrne & Hilbert argue that colors are reflectance properties of objects. They also claim that a necessary condition for something's being a color is that it causally explain – or be causally implicated in the explanation of – our perceptions of color. I argue that these two positions are in conflict.

The target article is an attempt to make some progress on the problem of color realism. Are objects colored? And what is the nature of the color properties? We defend the view that physical objects (for instance, tomatoes, radishes, and rubies) are colored, and that colors are physical properties, specifically types of reflectance. This is probably a minority opinion, at least among color scientists. Textbooks frequently claim that physical objects are not colored, and that the colors are "subjective" or "in (...) the mind." The article has two other purposes: first, to introduce an interdisciplinary audience to some distinctively philosophical tools that are useful in tackling the problem of color realism and, second, to clarify the various positions and central arguments in the debate. (shrink)

Our reply is in three parts. The first part concerns some foundational issues in the debate about color realism. The second part addresses the many objections to the version of physicalism about color ("productance physicalism") defended in the target article. The third part discusses the leading alternative approaches and theories endorsed by the commentators.

In many cases of variation in color vision, there is no non-arbitrary way of choosing between variants. Byrne and Hilbert insist that there is an unknown standard for choosing, while eliminativists claim that all the variants are erroneous. A better response relativizes colors to perceivers, thereby providing a color realism that avoids the need to choose between variants.

The problem of nonreflectors perceived as colored is the central problem for Byrne & Hilbert's (B&H's) physicalism. Vision scientists and other interested parties need to consider the motivation for their account of “productance physicalism.” Is B&H's theory motivated by scientific concerns or by philosophical interests intended to preserve a physicalist account of color as a posteriori necessary?

Byrne and Hilbert provide valuable clarification of the complexities–undreamt of by the layman–that make it hard to answer the question of what color is, and that often lead color scientists to say such remarkable and extravagant things. They emphasize at the outset that their issue is not just how to define the ordinary language term “color”: “The problem of color realism is like the investigation of what humans can digest, not the investigation of the folk category of food.” [ms p4], (...) but then I am puzzled by a tension in the target article regarding the weight they put on our ordinary intuitions about color. The very setting of the issue as a disagreement between “color realists” and “color eliminativists” endows the everyday concept with somewhat more authority than it deserves–comparable to an imaginary debate between biologists who were “food realists” and “food eliminativists”! (shrink)

This chapter focuses on the notion of color as a property of the surfaces of objects. It considers three positions on what colors are: objectivist, subjectivist, and relationalist. Examination of the arguments of the objectivists will help us understand how they seek to reduce color to a physical property of object surfaces. Subjectivists, by contrast, seek to argue that no such reduction is possible, and hence that color must be wholly subjective. This chapter argues that when functional considerations are taken (...) into account, a relationalist position best accommodates the primary data concerning color perception, and permits a better understanding of the ways in which color is both objective and subjective. The chapter ends with a reconsideration of the notions of objectivity and subjectivity themselves, and a consideration of how modern technology can foster misleading expectations about the specificity of color properties. (shrink)