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.

In this commentary I argue that Byrne & Hilbert commit a number of philosophical solecisms: They beg the question of “realism,” they take the phenomenon and the theoretical model to be the same thing, and they surreptitiously substitute data sets for the life-world.

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.

The colors we perceive are the outcome of an attempt to meaningfully order the spectral information from the environment. These colors are not the result of a straightforward mapping of a physical property to a sensation, but arise from an interaction between our environment and our visual system. Thus, although one may infer from a surface’ reflectance characteristics that it will be perceived as “colored,” true colors only arise by virtue of the interaction of the reflected light with the eye (...) (and brain) of an observer. (shrink)

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.

To identify the set of reflectances that constitute redness, the authors must first determine which surfaces are red. They do this by relying on widespread agreement among us. However, arguments based on the possible ways in which humans would perceive colors show that mere widespread agreement among us is not a satisfactory way to determine which surfaces are red.

Rationalizing the perceptual effects of spectral stimuli has been a major challenge in vision science for at least the last 200 years. Here we review evidence that this otherwise puzzling body of phenomenology is generated by an empirical strategy of perception in which the color an observer sees is entirely determined by the probability distribution of the possible sources of the stimulus. The rationale for this strategy in color vision, as in other visual perceptual domains, is the inherent ambiguity of (...) the real-world origins of any spectral stimulus. (shrink)

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.

One crucial premise in the argument from illusion is the Phenomenal Principle. It states that if there sensibly appears to be something that possesses a sensible quality, then there is something of which the subject is aware that has that sensible quality. The principle thus enables the inference from a mere appearance to an existence (usually a mental one). In the argument from appearance, a similar move is taken by some philosophers—they infer a content from a mere appearance. There are (...) two kinds of defences for the Phenomenal Principle in the literature, namely, the epistemological one (e.g. H.H. Price) and the semantic one (e.g. Frank Jackson). I argue that neither consolidates the Phenomenal Principle. I particularly demonstrate that the appearance verb in premise 1 of the argument from illusion is not used in the phenomenal sense as it is used in the Phenomenal Principle, which renders the argument essentially invalid. To avoid invalidity, the proponents either give up the phenomenal use, which makes the argument unable to serve its original purpose, i.e. inferring an unusual existence, or they insist on the phenomenal use in all premises of the argument, which will trivialise the argument. I also demonstrate that a similar objection applies to the argument from appearance. (shrink)

Do the physical facts of the viewed environment account for the ordinary experiences we have of that environment? According to standard philosophical views, distal facts do account for our experiences, a phenomenon explained by appeal to perceptual constancy, the phenomenal stability of objects and environmental properties notwithstanding physical changes in proximal stimulation. This essay reviews a significant but neglected research tradition in experimental psychology according to which percepts systematically do not correspond to mind-independent distal facts. Instead, stability of percept values (...) comes in degrees, and physical facts about the viewed environment alone do not account for our ordinary experiences of the world. I conclude that more attention to descriptive research in psychophysics is warranted if what is sought is a philosophical theory of the nature of our perceptual relation with the world. (shrink)

Perceptual constancy, often defined as the perception of stable features under changing conditions, goes hand in hand with variation in how things look. A white wall in the orange afternoon sun still looks white, though its whiteness looks different compared with the same wall in the noon sun. Historically, this variation has often been explained in terms of our experience of “merely sensory” or subjective properties – an approach at odds with the fact that the variation does track objective features (...) of the perceptual situation, such as illumination. One approach, becoming more common, is to account for the variation in terms of further “dimensions” to perceptual experience. Especially in colour perception, this is a natural thought to have but the idea is often left vague. In this paper I argue that the “dimensional” strategy has problems of its own, but is useful in drawing out some interesting complications in the way perceptual experience is structured. Specifically, the structure of “constancy spaces” brings out the different ways in which there is stability and instability in the experience of constancy, without the need for novel or merely subjective features. Instability arises in a contingent structural feature of perceptual experience. (shrink)

This paper explores the confrontation of physical and contextual factors involved in the emergence of the subject of color measurement, which stabilized in essentially its present form during the interwar period. The contentions surrounding the specialty had both a national and a disciplinary dimension. German dominance was curtailed by American and British contributions after World War I. Particularly in America, communities of physicists and psychologists had different commitments to divergent views of nature and human perception. They therefore had to negotiate (...) a compromise between their desire for a quantitative system of description and the perceived complexity and human-centeredness of color judgement. These debates were played out not in the laboratory but rather in institutionalized encounters on standards committees. Groups such as this constitute a relatively unexplored historiographic and social site of investigation. The heterogeneity of such committees, and their products, highlight the problems of identifying and following such ephemeral historical 'actors'. (shrink)

Although widely used across psychology, economics, and philosophy, the concept ofeffort is rarely ever defined. This article argues that the time is ripe to look for anexplicit general definition of effort, makes some proposals about how to arrive at thisdefinition, and suggests that a force-based approach is the most promising. Section 1presents an interdisciplinary overview of some chief research axes on effort, and arguesthat few, if any, general definitions have been proposed so far. Section 2 argues thatsuch a definition is (...) now needed and proposes a basic methodology to arrive at it, whosefirst step is to make explicit the various tacit assumptions about effort made acrosssciences and ordinary thinking. Section 3 unearths 4 different conceptions of effortfrom research on effort so far:primitive-feelings accounts,comparator-based accounts,resource-based accountsandforce-based accounts. It is then argued that the first 2kinds of accounts, although interesting in their own right, are not strictly speaking abouteffort. Section 4 considers the 2 most promising general approaches to efforts: re-source-based and force-based accounts. It argues that these accounts are not only compatible but actually extensionally equivalent. This notwithstanding, it explains why force-based accounts should be regarded as more fundamental than resource-basedaccounts -/- . (shrink)

The empirical study of visual space has centered on determining its geometry, whether it is a perspective projection, flat or curved, Euclidean or non-Euclidean, whereas the topology of space consists of those properties that remain invariant under stretching but not tearing. For that reason distance is a property not preserved in topological space whereas the property of spatial order is preserved. Specifically the topological properties of dimensionality, orientability, continuity, and connectivity define “real” space as studied by physics and are the (...) spatial properties that characterize the physical universe as being an integral whole. By contrast the geometrical analysis of VS has taken little cognizance of its topology. Instead such properties have been presupposed a priori rather than being established a posteriori by empirical means, perhaps because these properties are self-evident. Applying the method of coordinative definition expounded by Hans Reichenbach for determining geometrical and topological properties of physical space, it can be shown that VS fulfills the topological criteria of being a “real” space sui generis. Though theorized to be produced by the brain, the topology of VS is not topologically equivalent with the structure and activity of the brain because, as will be shown, the topology of VS cannot be formed from the topology of the brain without tearing and/or cutting and pasting. (shrink)

Since Aristotle, touch has been found especially hard to define. One of the few unchallenged intuition about touch, however, is that tactile awareness entertains some especially close relationship with bodily awareness. This article considers the relation between touch and bodily awareness from two different perspectives: the body template theory and the body map theory. According to the former, touch is defined by the fact that tactile content matches proprioceptive content. We raise some objections against such a bodily definition of touch (...) and suggest, as an alternative, to revive the proposal according to which touch is essentially a sense of pressure. According to the body map theory, tactile sensations are localized within the frame of reference provided by the mental representation of the space of the body. We argue that this approach of the location of bodily sensations fares better that the Local Sign theory that denies intrinsic spatiality to touch. (shrink)

I argue that when empty space is seen in mirrors—that is, when perceptual specular experience is veridical—specular empty space is, like pictorial empty space, seen-in. I explain how the phenomenal expansiveness of specular reflections can nonetheless be reconciled with the see-through look of specular space.

As demonstrated by several example displays, color illusions challenge color realism, because they involve a one-to-many reflectance-to-color mapping. Solving this problem by differentiating between veridical and illusory colors corresponding to the same reflectance is hampered because of the lack of an appropriate criterion. However, the difference between veridical and illusory color perception can still be maintained.

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.

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.

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.

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.

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?

We argue that any theory of color physicalism must include consideration of ecological interactions. Ecological and sensorimotor contingencies resulting from relative surface motion and observer motion give rise to measurable effects on the spectrum of light reflecting from surfaces. These contingencies define invariant manifolds in a sensory-spatial space, which is the physical underpinning of all subjective color experiences.

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)

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)

Summary Since at least the time of Helmholtz, the process of visual perception has been regarded as a two-stage affair consisting of an initial sensory stage corresponding to the proximal stimulus and a subsequent cognitive stage corresponding to the distal object. This construction amounts to an awkward mind body dualism wherein part of perception is done by the body and the other part is done by the mind. Gestalt theory rejected both raw sensations and their cognitive interpretation, offering a single (...) unified perceptual process that responds to an extended pattern of stimulation. They proposed organizational rules that describe how objects arise from the indifferent retinal mosaic. The same grouping principles by which objects are segmented also function to segregate regions of uniform illumination. Lightness values can then be computed by comparing luminance values within each such framework of illumination, with no need for the mystical concept of taking the illumination into account. (shrink)

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)

Students of perception have long known that perceptual constancy is an important aspect of our perceptual interaction with the world. Here is a simple example of the phenomenon concerning color perception: there is some ordinary sense in which an unpainted ceramic coffee cup made from a uniform material looks a uniform color when it is viewed under uneven illumination, even though the light reflected by the shaded regions to our eyes is quite different from the light reflected by the unshaded (...) regions to our eyes (see figure 1). Or consider this example concerning size perception: there is some ordinary sense in which two telephone poles look the same size when the first is viewed from 100 meters and when the second is viewed from 1 meter, even though the visual angle subtended by the two poles on our retinae is very different (see figure 2). Or consider this example concerning shape perception: there is some ordinary sense in which a penny looks round both when viewed head on and when viewed from an acute angle, even though the area projected by the penny onto our retinae under these two conditions is very different (see figure 3). Or, finally, consider this example concerning auditory volume perception (which I cannot depict graphically): there is some ordinary sense in which a speaker’s voice sounds the same volume when heard from across the room and when heard from a distance of 1 meter, even though the energy striking our ears under these two conditions is very different. (shrink)

Recent philosophy of mind has tended to treat.

In recent years phenomenology has attracted the interest of science, acquiring a role far beyond philosophy. Despite Husserl's clear denial of a possible naturalization of phenomenology, scientists from different fields have proposed its naturalization. To achieve this goal, different methodologies have been proposed. Most scientists seem to agree on the claim that phenomenology cannot be a science itself because it fails to respect one of the prerequisites of science, that is, the capacity to explain its phenomena. Phenomenology, thus, is forced (...) to remain a purely descriptive effort, preliminary to authentic scientific practice. I argue, instead, that the experimental development of phenomenology explains phenomena (that is, appearances and/or subjective experiences in first person account) and uses rigorous methods, conducts valid measurements, and can validate its results. The paper provides a variety of examples of how experimental phenomenology works. (shrink)

Loneliness is more complex and multi-faceted than it may appear at first glance. Most of the characterizations that we have of loneliness in the extant literature tend to focus on the absence of other people and on the social, mental, and physical distress that can be caused by this type of absence. Although the experience of absence may be a fundamental and encompassing aspect of loneliness, loneliness may also reflect a deeper, more complex experience. This paper integrates data from a (...) qualitative study on the phenomenology of loneliness with philosophical theories on the self. It argues that there is a connection between the experience of absence and the impossibility to appear in the world and that this may consequentially lead to the disruption of self-experience. (shrink)

Summary The present paper introduces the theoretical conceptualization of perceptual communication through expressive qualities. Initially, the difference with respect to the modality of perceptual communication mediated by signs is analyzed. Conversely, the theory of expressive qualities reflects the psychological conception of direct perception: any assumption of a cognitive stage of representation is excluded. Perceptual communication immediately expresses the specific character of the structural essence of the object. The structural essence is well studied by the perceptual paradigms of Experimental Phenomenology. Plurivocity, (...) the case in which the same objects can share many expressive characters, is also considered. (shrink)

I argue that Byrne & Hilbert (B&H) have not answered Hardin's objection to physicalism about color concerning the unitary-binary structure of the colors for two reasons. First, their account of unitary-binary structure seems unsatisfactory. Second, pace B&H, there are no physicalistically acceptable candidates to be the hue-magnitudes. I conclude with a question about the justification of physicalism about color.

A coin rotating back in depth in some sense presents a changing, elliptical shape. How are we to understand such (in this case) ‘appearances of ellipticality’? How is the experiential sense of such shifting shape appearances related to the experiential sense of enduring shape definitive of perceived shape constancy? Is the experiential recovery of surface shape based on the prior (perhaps more fundamental) recovery of point or element 3D spatial locations?—or is the perception of shape a largely independent perceptual achievement? (...) Do we gain access to enduring shape properties by first detecting and working from ‘shape appearances’? These are some of the topics taken up in this paper. (shrink)

I draw on Carl Stumpf’s essay “Psychologie und Erkenntnistheorie”, and his precocious On the Psychological Origin of the Idea of Space, to set out a charge he raises against Kant’s fo...

It is a common assumption among philosophers of perception that phenomenal colors are exhaustively characterized by the three phenomenal dimensions of the color solid: hue, saturation and lightness. The hue of a color is its redness, blueness or yellowness, etc. The saturation of a color refers to the strength of its hue in relation to gray. The lightness of a color determines its relation to black and white. In this paper, I argue that the phenomenology of shadows forces us to (...) consider illumination as an additional dimension of phenomenal colors. For this purpose, I will first introduce two different interpretations of shadow-experiences, which Chalmers has called the simple and the complex interpretations, and show that they both fail to account for important phenomenal facts about shadow-experiences. I will then introduce my own alternative interpretation based on the idea that illumination is a dimension of phenomenal colors and explain how it can account for these facts. (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.

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.

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)

Space—an essential dimension of our life—is analyzable from different viewpoints, which often gives rise to contrasting conceptualizations. Perceptual analyses shed light on the intrinsic anisotropy and deformations of perceived space, raising the issue of which geometry may be able to represent perceptual space. Pictorial drawings and painting have been relevant sources of information about the nature of living and perceived space. Although the geometry of perceptual space is still in its infancy, contributions are beginning to appear. This special issue contributes (...) to the development of the geometry of perceptual space. (shrink)

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 ArgumentThis paper explores the confrontation of physical and contextual factors involved in the emergence of the subject of color measurement, which stabilized in essentially its present form during the interwar period. The contentions surrounding the specialty had both a national and a disciplinary dimension. German dominance was curtailed by American and British contributions after World War I. Particularly in America, communities of physicists and psychologists had different commitments to divergent views of nature and human perception. They therefore had to (...) negotiate a compromise between their desire for a quantitative system of description and the perceived complexity and human-centeredness of color judgment. These debates were played out not in the laboratory but rather in institutionalized encounters on standards committees. Such groups constitute a relatively unexplored historiographic and social site of investigation. The heterogeneity of such committees, and their products, highlight the problems of identifying and following such ephemeral historical “actors”. (shrink)

Students of perception have long puzzled over a range of cases in which perception seems to tell us distinct, and in some sense conflicting, things about the world. In the cases at issue, the perceptual system is capable of responding to a single stimulus — say, as manifested in the ways in which subjects sort that stimulus — in different ways. This paper is about these puzzling cases, and about how they should be characterized and accounted for within a general (...) theory of perception. After rehearsing the sort of case at issue (§1), I’ll examine critically some of the strategies by which philosophers and perceptual psychologists have attempted to account for them (§2). Finally, I’ll present an alternative computational account of the puzzle cases, argue that this view is superior to its competitors, and examine some of its implications (§3). (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.

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.

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.

The paper presents analysis of form in different domains. It draws on the commonalities and their potential unified classifications based on how forms subjectively appear in perception—as opposed to their standard specification in Euclidean geometry or other objective quantitative methods. The paper provides an overview aiming to offer elements for thought for researchers in various fields.