Online research in philosophy

Paul Churchland has recently offered a novel argument for the “objective reality” of color. The strategy he employs to make this argument is an instance of a more general research program for interpreting perceptual content, “domain‐portrayal semantics.” In the first half of the article, I point out some features of color vision that complicate Churchland's conclusion, in particular, the context‐sensitive and inferential nature of color perception. In the second half, I examine and defend the general research program, concluding it is naturalistic in a minimal sense and should be of interest to naturalists and nonnaturalists alike. †To contact the author, please write to: Department of Philosophy, Stanford University, Stanford, CA 94305; e‐mail: aisaac@post.harvard.edu.

Byrne & Hilbert (B&H) 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.”.

Color subjectivists claim that, despite appearances to the contrary, the world external to the mind is colorless. However, in giving an account of color perception, subjectivists about the nature of perceived color must address the nature of perceived spatial location as well. The argument here will be that subjectivists’ problems with coordinating the metaphysics of perceived color and perceived location render color perception implausibly mysterious. Consequently, some version of color realism, the view that colors are (physical, dispositional, functional, sui generis, or some other) properties of physical objects, is correct.

The relations among consciousness, brain, behavior, and scientific explanation are explored in the domain of color perception. Current scientific knowledge about color similarity, color composition, dimensional structure, unique colors, and color categories is used to assess Locke.

According to color subjectivism, colors are mental properties, processes, or events of visual experiences of color. I first lay out an argument for subjectivism founded on claims from visual science and show that it also relies on a philosophical assumption. I then argue that subjectivism is untenable because this view cannot provide a plausible account of color perception. I describe three versions of subjectivism, each of which combines subjectivism with a theory of perception, namely sense datum theory, adverbialism, and the virtual color proposal, and argue that each version faces serious objections. Considering these three theories of perception to be exhaustive of those available to the subjectivist, I conclude that subjectivism is untenable and that the scientifically motivated argument for this view is unsound. I then offer the diagnosis that the philosophical assumption on which this argument relies is mistaken.

This paper proposes a subjectivist approach to color within the framework of an externalist form of representationalism about phenomenal consciousness. Motivations are presented for accepting both representationalism and color subjectivism, and an argument is offered against the case made by Michael Tye on behalf of the claim that colors are objective, physical properties of objects. In the face of the considerable difficulties associated with finding a workable realist theory of color, the alternative account of color experience set out, projectivist representationalism, claims that the color properties we encounter in experience exist only in the representational contents of our experiences. Color experiences are caused by the physical structure of objects, but objects are never actually colored and color experiences systematically misrepresent objects as colored. However, despite being an error theory of color, projectivist representationalism does not do violence to our everyday use and understanding of color concepts and terms, nor does it undermine the role of color experience in aiding the perceiving subject in navigating through the world.

What knowledge of the colors does perception of the colors provide? My first aim in this essay is to characterize the way in which color experience seems to provide knowledge of colors. This in turn tells us something about what it takes for there to be colors. Color experience provides knowledge of the aspect of the world that is being acted on when we, or some external force, act on the color of an object and thus make a difference to the experiences of people looking at it. It is in this sense that the nature of the colors is transparent to us. For there to be colors is for there to be the qualitative categorical properties that we encounter in perception, action on which affects the color experiences of observers. This line of thought contrasts with the idea that color experience reveals the colors to us, in the sense that it provides knowledge of a number of necessary truths about the colors. In a recent paper, Alex Byrne and David Hilbert provide a careful exposition and critique of this way of developing the idea of color experience as revelatory of the colors. In this paper my main aim is simply to contrast the idea that experience makes the colors transparent to us, with the idea that color experience provides us with knowledge of truths relating to the essences of the colors.

In 1995, in my book, Ten Problems of Consciousness (Bradley Books, MIT Press), I proposed a version of the theory of phenomenal consciousness now known as representationalism. The present book, in part, consists of a further development of that theory along with replies to common objections. It is also concerned with two prominent challenges for any reductive theory of consciousness: the explanatory gap and the knowledge argument. In addition, it connects representationalism with two more general issues: the nature of color and the location of the phylogenetic dividing line between those creatures that are phenomenally conscious and those that are not.

What is the relationship between color experience and color? Here, I defend the view that it is semantic: color experience denotes color in a code innately known by the perceiver. This semantic theory contrasts with a variety of theories according to which color is defined as the cause of color experience (in a special set of circumstances). It also contrasts with primary quality theories of color, which treat color as a physical quantity. I argue that the semantic theory better accounts for the kinds of knowledge we have regarding both the color of objects that we see and of the colors themselves.

I respond to the separate commentaries by Jacob Berger, Charlie Pelling, and David Pereplyotchik on my paper, “Color-Consciousness Conceptualism.” I resist Berger’s suggestion that mental colors ever enter consciousness without accompaniment by deployments of concepts of their extra-mental counterparts. I express concerns about Pelling’s proposal that a more uniform conceptualist treatment of phenomenal sorites can be gained by a simple appeal to the partial overlap of the extensions of some concepts. I question the relevance to perceptual consciousness of the arguments for demonstrative concepts that Pereplyotchik attacks.