A stubborn problem for reflectance physicalism about color is to account for individual differences in normal trichromat color perception. The identification of determinate colors with physical properties of visible surfaces in a universal, perceiver-independent way is challenged by the observation that the same surfaces in identical viewing conditions often look different in color to different human subjects with normal color vision. Recently, leading representatives of reflectance physicalism have offered some arguments to defend their view against the individual differences challenge. In (...) this paper I challenge their defense. I argue thateven though individual differences are present in shape perception as well as in color perception, the mechanisms of shape perception and those of color perception differ in ways which make them completely different regarding their evidential status for certain identity claims. Thus comparing color perception to shape perception offers no support for identifying hues with reflectances. On the other hand, drawing a parallel between the temperature-mean kinetic energy of molecules (MKE) identification and the proposed hue-reflectance identities is no support for reflectance physicalism either, since there is an important disanalogybetween the two cases. While individual differences obtain in color perception, the effects of temperature (e.g., melting, thermal expansion) do not exhibit analogous variation, which makes the temperature-MKE identification unproblematic compared to the hue-reflectance identification. One motivation for this ongoing debate is that the success or failure of reflectance physicalism has far-reaching consequences regarding externalist theories of phenomenal consciousness. (shrink)

Experimental philosophy is often presented as a new movement that avoids many of the difficulties that face traditional philosophy. This article distinguishes two views of experimental philosophy: a narrow view in which philosophers conduct empirical investigations of intuitions, and a broad view which says that experimental philosophy is just the colocation in the same body of (i) philosophical naturalism and (ii) the actual practice of cognitive science. These two positions are rarely clearly distinguished in the literature about experimental philosophy, both (...) pro and con. The article argues, first, that the broader view is the only plausible one; discussions of experimental philosophy should recognize that the narrow view is a caricature of experimental philosophy as it is currently done. It then shows both how objections to experimental philosophy are transformed and how positive recommendations can be provided by adopting a broad conception of experimental philosophy. (shrink)

I will develop a new problem for almost all realist theories of colour. The problem involves fluctuations in our colour experiences that are due to visual noise rather than changes in the objects we are looking at.

In this paper, I propose a fictionalist approach to the problem of color. On my view, which I call prescriptive color fictionalism, we can continue to employ our color discourse as we have thus far even if it turns out that there are no colored objects. My proposal is a species of error theory. As such, it does not describe our current practices. It is rather proposed as a prescription to a problem, namely that the color theory we accept (according (...) to which there are colored objects) is false. By formulating a fictionalist account of color and showing that we can preserve ordinary color discourse in the absence of colored objects, I provide a solution to the problem of color. (shrink)

1. IntroductionA considerable number of philosophers maintain that meaning is intrinsically normative. In this journal, Daniel Whiting has defended the normativity of meaning against some of my recent objections . 1 This paper responds to Whiting's arguments.

Color relationalism is the view that colors are constituted in terms of relations between subjects and objects. The most historically important form of color relationalism is the classic dispositionalist view according to which, for example red is the disposition to look red to standard observers in standard conditions (mutatis mutandis for other colors).1 However, it has become increasingly apparent in recent years that a commitment to the relationality of colors bears interest that goes beyond dispositionalism (Cohen, 2004; Matthen, 1999, 2001, (...) 2005; Thompson, 1995). Accordingly, it is an important project for those interested in the metaphysics of color to sort through and assess different forms of color relationalism. There is, however, a powerful and general cluster of objections that has been thought by many to amount to a decisive refutation of any and all forms of color relationalism. Although this idea has been developed in a number of ways, the basic thought is that relationalism — qua theory of color — is at odds with the manifest evidence of color phenomenology, and that this clash between theory and data should be resolved by giving up the theory. (shrink)

Vision scientists are interested in three diverse entities: physical stimuli, neural states, and consciously perceived colors, and in the mapping rules among the three. In this worldview, the three kinds of entities have coequal status, and views that attribute color exclusively to one or another of them, such as color realism, have no appeal.

Colors are of philosophical interest for two kinds of reason. One is that colors comprise such a large and important portion of our social, personal and epistemological lives and so a philosophical account of our concepts of color is highly desirable. The second reason is that trying to fit colors into accounts of metaphysics, epistemology and science leads to philosophical problems that are intriguing and hard to resolve. Not surprisingly, these two kinds of reasons are related. The fact that colors (...) are so significant in their own right, makes more pressing the philosophical problems of fitting them into more general metaphysical and epistemological frameworks. (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.

Color relationalism is the view that colors are constituted in terms of relations to perceiving subjects. Among its explanatory virtues, relation- alism provides a satisfying treatment of cases of perceptual variation. But it can seem that relationalists lack resources for saying that a representa- tion of x’s color is erroneous. Surely, though, a theory of color that makes errors of color perception impossible cannot be correct. In this paper I’ll argue that, initial appearances notwithstanding, relationalism contains the resources to account (...) for errors of color perception. I’ll conclude that worries about making room for error are worries the relationalist can meet. (shrink)

This paper surveys some recent work on realization in the philosophy of mind and the philosophy of science.

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)

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)

“The problem of color realism” as defined in the first section of the target article, is crucial to the argument laid out by Byrne & Hilbert. They claim that the problem of color realism “does not concern, at least in the first instance, color language or color concepts” (sect. 1.1). I argue that this claim is misconceived and that a different characterisation of the problem, and some of their preliminary assumptions makes their positive proposal less appealing.

Byrne & Hilbert conceive of color perception as the representation of a physical property “out there.” In our view, their approach does not only have various internal problems, but is also apt to becloud both the intricate and still poorly understood role that “ color ” plays within perceptual architecture, and the complex coupling to the “external world” of the perceptual system as an entirety. We propose an alternative perspective, which avoids B&H's misleading dichotomy between a purely subjective and a (...) realist conception of “ color.”. (shrink)

It commonly occurs that one person sees a particular colour chip B as saturated blue with no admixture of red or green (i.e., as “uniquely blue”), while another sees it as a somewhat greenish blue. Such a difference is often accompanied by agreement with respect to colour matching – the two persons may mostly agree when asked whether two chips are of the same colour, and this may be so across the whole range of colours. Asked whether B is the (...) same or different from other chips, they mostly agree – though they continue to disagree about whether B is uniquely blue. I shall argue that in such cases neither individual misperceives what colour B is. They differ, rather, in how they perceive the colour of B. (shrink)

Mazviita Chirimuuta proposes a new “adverbialist” ontology of color. I argue that ontological disputes in the philosophy of color are uniformly terminological. Chirimuuta's proposal too is a terminological variant on others, though it has some hortatory value in directing attention to aspects of color science that have hitherto been neglected. On a side note, I also take issue with Chirimuuta's laudatory take on early modern theories of color.

Scientists are often bemused by the efforts of philosophers essaying a theory of colour: colour science sports a huge array of facts and theories, and it is unclear to its practitioners what philosophy can or is trying to contribute. Equally, philosophers tend to be puzzled about how they can fit colour science into their investigations without compromising their own disciplinary identity: philosophy is supposed to be an _a priori_ investigation; philosophers do not work in psychophysics labs – not in their (...) professional capacity, anyway. (shrink)

Aristotle held that perception consists in the reception of external sensory qualities (or sensible forms) in the sensorium. This idea is repeated in many forms in contemporary philosophy, including, with regard to vision, in the idea (still not firmly rejected) that the retinal image consists of points of colour. In fact, this is false. Colour is a quality that is constructed by the visual system, and though it is possible to be a realist about colour, it is completely misleading to (...) think of it as received by the retina. Moreover, such supposedly “charitable” interpretations of Aristotle’s doctrines, based on miscon- ceptions of perception-science, distort our understanding of his historical context. (shrink)

Byrne & Hilbert are right that it might be an objective fact that a particular tomato is unique red, but wrong that it cannot simultaneously be yellowish-red (not only objectively, but from somebody else's point of view). Sensory categorization varies among organisms, slightly among conspecifics, and sharply across taxa. There is no question of truth or falsity concerning choice of categories, only of utility and disutility. The appropriate framework for color categories is Nominalism and Pluralistic Realism.

Byrne & Hilbert propose that color can be identified with explicit properties of physical surfaces. I argue that this claim must be qualified to take into account constraints needed to make recovery of surface color information possible. When these constraints are satisfied, then a biological visual system can establish a correspondence between perceived surface color and specific surface properties.

For all animals, color is an indicator of the substance and state of objects, for which purpose reflectance is just one among many relevant optical properties. This broader meaning of color is confirmed by linguistic evidence. Rather than reducing color to a simple physical property, it is more realistic to embrace its full phenomenology.

Our conscious experiences are qualitative and unitary. The qualitative universals given in particular experiences, i.e. qualia, combine into the seamless unity of our conscious experience. The problematics of quality and cohesion are not unique to consciousness studies. In mathematics, the study of qualities (e.g., shape) resulting from quantitative variations in cohesive spaces led to the axiomatization of cohesion and quality. Using the mathematical definition of quality, herein we model qualia space as a categorical product of qualities. Thus modeled qualia space (...) is a codomain space wherein composite qualities (e.g. shape AND color) of conscious experiences can be valued. As part of characterizing the qualia space, we provide a detailed exemplification of the mathematics of quality and cohesion in terms of the categories of idempotents and reflexive graphs. More specifically, with qualities as commutative triangles formed of cohesion-preserving functors, first we calculate the product of commutative triangles. Next, we explicitly show that the category of idempotents is a quality type. Lastly, as part of showing that the category of reflexive graphs is cohesive, we characterize the adjointness between functors relating cohesive graphs to discrete sets. In conclusion, our category theoretic construction of qualia space is a formalization of the binding of qualitative features (colors and shapes) into the cohesive objects (colored-shapes) of conscious experiences. Compared to the feature-vector accounts of conscious experiences, our product-of-qualities account of consciousness is a substantial theoretical advance. (shrink)

Revelation, the thesis that the full intrinsic nature of colors is revealed to us by color experiences, is false in Byrne & Hilbert's (B&H's) view, but in an interesting and nonobvious way. I show what would make Revelation true, given B&H's account of colors, and then show why that situation fails to obtain, and why that is interesting.

Reflectance and spectral power functions are poor predictors of color experiences. Only in completely relativized conditions (single observer, non-metameric set of stimuli, and single set of viewing conditions) is the relationship close. Variation in reflectance of Munsell chips experienced by color-normal observers as having a unique green hue encompasses approximately sixty percent of the complete range of hues falling under the category “green”; and in recent determinations of unique hues, ranges of yellow and green as well as green and blue (...) unique hues overlap. (shrink)

H.-J. Glock has made important contributions to discussions of rationality, reasons, and rules. This chapter addresses four conceptions of rationality that Glock identifies. One of these conceptions of rationality is that rationality consists in responsiveness to reasons. This chapter goes on to consider the idea that reasons became prominent in normative ethics because of their usefulness in articulating moral pluralism. The final section of the chapter connects reasons and rules and contends that both are ineliminable.

In this paper I propose and defend an account of color that I call color functionalism. I argue that functionalism is a non-traditional species of primary quality theory, and that it accommodates our intuitions about color and the facts of color science better than more widely discussed alternatives.

Along with hallucinations and illusions, afterimages have shaped the philosophical debate about the nature of perception. Often referred to as optical or visual illusions, experiences of afterimages have been abundantly exploited by philosophers to argue against naïve realism. This paper offers an alternative account to this traditional view by providing a tentative account of the colors of the afterimages from an objectivist perspective. Contrary to the widespread approach to afterimages, this paper explores the possibility that the colors of afterimages are (...) not ontologically different from “ordinary” colors and that experiences of afterimages fail to provide a motivation for rejecting naïve realism. (shrink)

We make three points. First, the concept of productance value that the authors propose in their defense of color physicalism fails to do the work for which it is intended. Second, the authors fail to offer an adequate physicalist account of what they call the hue-magnitudes. Third, their answer to the problem of individual differences faces serious difficulties.

A traditional explanation that dates back to Aristotle is that we access color in one perceptual modality only, whereas shape we perceive via two different modalities: visual and tactile. Two independent modalities make possible a verification of our percepts which is not possible for qualities accessed in one modality only.

In this paper I shall defend a projectivist view of sensory experience. The case I shall focus on is that of color experience. Projectivism has recently been criticized by some authors who claim that it is unintelligible, or at least implausible, and that it makes a severe category mistake. I shall argue that despite some prima facie impressions of implausibility, projectivism can be made intelligible, and plausible, if its details are spelled out in a reasonable way. In addition, projectivism is (...) ubiquitous in human psychology, and certain cases of projection are reasonably viewed as making a category mistake. Viewed from this perspective, sensory projection is just one instance of projectivism, brought about by low-level perceptual processing. Whether sensory projection is one that makes a category mistake is not obvious. However, even if it does, this is perfectly compatible with the evolutionary advantage of sensation and perception. (shrink)

Those who identify colours with physical properties need to say how the content of colour experiences relate to their favoured identifications. This is because it is not plausible to hold that colour experiences represent things as having the physical properties in question. I sketch how physical realists about colour might tackle this item of unfinished business.

B&H understate the difficulties facing their version of color realism. We doubt that they can fix reflectance types and magnitudes in a way that does not invoke relations to perceivers. B&HÂ’s account therefore resembles the dispositional or ecological accounts that they dismiss. This is a good thing, for a dispositional account is promising if understood in an ecological framework.

Significant variations in the way objects appear across different viewing conditions pose a challenge to the view that they have some true, determinate color. This view would seem to require that we break the symmetry between multiple appearances in favor of a single variant. A wide range of philosophical and non-philosophical writers have held that the symmetry can be broken by appealing to daylight viewing conditions—that the appearances of objects in daylight have a stronger, and perhaps unique, claim to reveal (...) their true colors. In this note we argue that, whatever else its merits, this appeal to daylight is not a satisfactory answer to the problem posed by perceptual variation. (shrink)

Because our only access to color qualities is through their appearance, Byrne & Hilbert's insistence on a strict distinction between apparent colors and real colors leaves them without a principled way of determining when, if ever, we see colors as they really are.

There are 2,000 hair cells in the cochlea, but only three cones in the retina. This disparity can be understood in terms of the differences between the physical characteristics of the auditory signal (discrete excitations and resonances requiring many narrowly tuned receptors) and those of the visual signal (smooth daylight excitations and reflectances requiring only a few broadly tuned receptors). We argue that this match supports the physicalism of color and timbre.

Metamerism is a rather common feature of objects. The authors see it as problematic because they are concerned with a special case: metamerism in standard conditions. Such metamerism does not, however, pose a problem for color realists. There is an apparent problem in cases of metameric light sources, but to see such metamers as problematic is to fail to answer Berkeley's challenge.

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)

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.

Studies show that there are widespread intrasubjective and intersubjective color variations among normal perceivers. These variations have serious ramifications in the debate about the nature and ontology of color. It is typical to think of the debate about color as a dispute between objectivists and subjectivists. Objectivists hold that colors are perceiver-independent physical properties of objects while subjectivists hold that they are either projections onto external objects or dispositions objects have to look colored. I argue that individual color variations present (...) difficulties, albeit not the same kind, for both objectivism and subjectivism. Lastly, I propose an alternative account that handles such variations nicely. (shrink)

Byrne & Hilbert's thesis, that color be associated with reflectance-type, is questioned on the grounds that it is far from clear that the human visual system is able to determine a surface's reflectance-type with sufficient accuracy. In addition, a (friendly) suggestion is made as to how to amend the definition of reflectance-type in terms of CIE (Commission Internationale de l'Eclairage) coordinates under a canonical illuminant.

Byrne & Hilbert defend color realism, which assumes that: (a) colors are properties of objects; (b) these objects are physical; hence, (c) colors are physical properties. I accept (a), agree that in a certain sense (b) can be defended, but reject (c). Colors are properties of perceptual objects – which also have underlying physical properties – but they are not physical properties.

The reflectance types that Byrne & Hilbert identify with colors count as types only in a way that is more dependent on, and more relative to color perceivers, than their account suggests. Their account of perceptual content may be overly focused on input conditions and distal causes.

Visual percepts are called veridical when a “real” object can be identified as their cause, and illusions otherwise. The perceived position and color of a flashed object may be called veridical or illusory depending on which viewpoint one adopts. Since “reality” is assumed to be fixed (independent of viewpoint) in the definition of veridicality (or illusion), this suggests that “perceived” position and color are not properties of “real” objects.

Byrne & Hilbert (B&H) assert that reflectances embody the reality of color, but metamerism smears the authors' “real” color categories into uselessness. B&H ignore this problem, possibly because they implicitly adopt a sort of subjectivism, whereby an object is defined by the percepts (or more generally by the measurements) it engenders. Subjectivism is unwieldy, and hence prone to such troubles.

Inter-species variation in colour perception poses a serious problem for the view that colours are mind-independent properties. Given that colour perception varies so drastically across species, which species perceives colours as they really are? In this paper, I argue that all do. Specifically, I argue that members of different species perceive properties that are determinates of different, mutually compatible, determinables. This is an instance of a general selectionist strategy for dealing with cases of perceptual variation. According to selectionist views, objects (...) simultaneously instantiate a plurality of colours, all of them genuinely mind-independent, and subjects select from amongst this plurality which colours they perceive. I contrast selectionist views with relationalist views that deny the mind-independence of colour, and consider some general objections to this strategy. (shrink)

In the good old days, when general philosophy of science ruled the Earth, a simple division was often invoked to talk about philosophical issues specific to particular kinds of science: that between the natural sciences and the social sciences. Over the last 20 years, philosophical studies shaped around this dichotomy have given way to those organized by more fine-grained categories, corresponding to specific disciplines, as the literatures on the philosophy of physics, biology, economics and psychology--to take the most prominent four (...) examples--have blossomed. In general terms, work in each of these areas has become increasingly enmeshed with that in the corresponding science itself, increasingly naturalistic (in at least one sense of that term), and in my view, increasingly interesting. (shrink)

Are colors relational or non-relational properties of their bearers? Is red a property that is instantiated by all and only the objects with a certain intrinsic (/non-relational) nature? Or does an object with a particular intrinsic (/non-relational) nature count as red only in virtue of standing in certain relations - for example, only when it looks a certain way to a certain perceiver, or only in certain circumstances of observation? In this paper I shall argue for the view that color (...) properties are relational (henceforth, relationalism), and against the view that colors are not relational (henceforth, anti- or non-relationalism). (shrink)