This paper resolves a paradox concerning colour constancy. On the one hand, our intuitive, pre-theoretical concept holds that colour constancy involves invariance in the perceived colours of surfaces under changes in illumination. On the other, there is a robust scientific consensus that colour constancy can persist in cerebral achromatopsia, a profound impairment in the ability to perceive colours. The first stage of the solution advocates pluralism about our colour constancy capacities. The second details the close relationship between colour constancy and (...) contrast. The third argues that achromatopsics retain a basic type of colour constancy associated with invariants in contrast processing. The fourth suggests that one person-level, conscious upshot of such processing is the visual awareness of chromatic contrasts ‘at’ the edges of surfaces, implicating the ‘colour for form’ perceptual function. This primitive type of constancy sheds new light on our most basic perceptual capacities, which mark the lower borders of representational mind. (shrink)

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)

In this article, I argue that popular explanatory frameworks in perceptual psychology suggest the truth of color realism. I focus on perceptual judgments and their evidential basis: namely perceptual representation. I first draw a distinction between two sorts of normativities with respect to which we can evaluate representational capacities and systems: biological and psychological normativities. The former is defined in terms of evolutionary fitness, and the latter in terms of representational accuracy. Generally, representational systems achieve psychological and biological success hand (...) in hand, but in special circumstances, a representational system can be such that it serves the organism best while not generally furnishing the organism with accurate representations. I argue in this essay that an explanation how and why our ancestors developed color vision that cleaves its biological success conditions from its psychological success conditions cannot be given unless we are prepared to say the same about the visual perception of distance and other geometrical features of the world. Moreover, it is difficult to see how the anti-realist could begin to specify psychological success conditions for color representations. Hence, we ought to accept the biological utility of color vision as evidence that it is typically representationally successful, and regard our perceptual judgments about color as generally true. (shrink)

Colour vision plays a foundational explanatory role in the philosophy of colour, and serves as perennial quarry in the wider philosophy of perception. I present two contributions to our understanding of this notion. The first is to develop a constitutive approach to characterizing colour vision. This approach seeks to comprehend the nature of colour vision qua psychological kind, as contrasted with traditional experiential approaches, which prioritize descriptions of our ordinary visual experience of colour. The second contribution is to argue that (...) colour vision does not constitutively involve the ability to see colours, in a natural and categorically committed sense. I argue that two subjects exactly alike in respect of their constitutive colour vision abilities could differ in respect of whether or not they have categorical perception of colour. The argument is supported by thought experiment and dissociations observed in cognitive neuropsychology. The argument also bears connections to recent neo-Whorfian accounts of colour categorization. _1._ Introduction _2._ Colour Vision, Experience, and Natures _3._ The Central Argument _3.1._ Colour constancy and discrimination _3.2._ Dissociating colour vision and categorical perception for colour _4._ Whorf and the View from Cognitive Neuropsychology _5._ Conclusion. (shrink)

David Enoch, in his paper “Why Idealize?”, argues that theories of normative reasons that hold that normative facts are subject or response-dependent and include an idealization condition might have a problem in justifying the need for idealization. I argue that at least some response-dependence conceptions of normative reasons can justify idealization. I explore two ways of responding to Enoch’s challenge. One way involves a revisionary stance on the ontological commitments of the normative discourse about reasons. To establish this point, I (...) argue by analogy with the case of color perception. To make the analogy, it suffices to show that even if colors are response-dependent properties, it does not follow that some kind of idealization cannot be introduced to specify the truth conditions of color ascriptions. The second route involves the denial of Enoch’s contention that our normative discourse is implicitly committed to a realist ontology. I adduce reasons for thinking that our normative discourse only presupposes a possibility of misrepresentation. However, this feature of the normative discourse does not favor robustly objectivist as opposed to response-dependence accounts of normative reasons. Thus, I argue that proponents of response-dependence accounts can use this feature to answer the question of why to idealize. (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)

Colour constancy is a foundational and yet puzzling phenomenon. Standard appearance invariantism is threatened by the psychophysical matching argument, which is taken to favour variantism. This argument, however, is inconclusive. The data at best support a pluralist view: colour constancy is sometimes variantist, sometimes invariantist. I add another potential explanation of these data, complex invariantism, which adopts an atypical six-dimensional model of colour appearance. Finally I prospect for a unifying conception of constancy among two neglected notions: discriminatory colour constancy and (...) relational colour constancy. The former arguably marks a common core capacity that is present across widely differing viewing contexts. (shrink)