Jonathan Cohen

Philosophers and scientists have long speculated about the nature of color. Atomists such as Democritus thought color to be "conventional," not real; Galileo and other key figures of the Scientific Revolution thought that it was an erroneous projection of our own sensations onto external objects. More recently, philosophers have enriched the debate about color by aligning the most advanced color science with the most sophisticated methods of analytical philosophy. In this volume, leading scientists and philosophers examine new problems with new analytic tools, considering such topics as the psychophysical measurement of color and its implications, the nature of color experience in both normal color-perceivers and the color blind, and questions that arise from what we now know about the neural processing of color information, color consciousness, and color language. Taken together, these papers point toward a complete restructuring of current orthodoxy concerning color experience and how it relates to objective reality. Kuehni, Jameson, Mausfeld, and Niederee discuss how the traditional framework of a three-dimensional color space and basic color terms is far too simple to capture the complexities of color experience. Clark and MacLeod discuss the difficulties of a materialist account of color experience. Churchland, Cohen, Matthen, and Westphal offer competing accounts of color ontology. Finally, Broackes and Byrne and Hilbert discuss the phenomenology of color blindness. Contributors: Justin Broackes, Alex Byrne, Paul M. Churchland, Austen Clark, Jonathan Cohen, David R. Hilbert, Kimberly A. Jameson, Rolf Kuehni, Don I.A. MacLeod, Mohan Matthen, Rainer Mausfeld, Richard Niederée, Jonathan Westphal The hardcover edition does not include a dust jacket.

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.

One of the most salient facts about our experience of the world is that objects appear to have colors. This feature of our experience is both striking and pervasive. Indeed, representations of colors of objects are among the most notable deliverances of the visual modality, which is perhaps our most important source of information about the world. For this reason, among others, questions about the nature of color have crucial significance for a variety of philosophical subjects including perception, ontology, epistemology, semantics, and philosophy of mind. But the nature of color is a fascinating philosophical topic in its own right, and there has been a significant increase in the philosophical attention paid to this matter in recent years. In this essay I'll survey some of the main views about the nature of color in the contemporary literature and attempt to lay out some of the arguments that have been used to support or reject various of these accounts.

An important motivation for relational theories of color is that they resolve apparent conflicts about color: x can, without contradiction, be red relative to S1 and not red relative to S2. Alas, many philosophers claim that the view is incompatible with naive, phenomenally grounded introspection. However, when we presented normal adults with apparent conflicts about color (among other properties), we found that many were open to the relationalist's claim that apparently competing variants can simultaneously be correct. This suggests that, philosophers' claims to the contrary notwithstanding, introspection does not supply authoritative and unambiguous reason to reject color relationalism.

It can happen that a single surface S, viewed in normal conditions, looks pure blue (“true blue”) to observer John but looks blue tinged with green to a second observer, Jane, even though both are normal in the sense that they pass the standard psychophysical tests for color vision. Tye (2006a) finds this situation prima facie puzzling, and then offers two different “solutions” to the puzzle.1 The first is that at least one observer misrepresents S’s color because, though normal in the sense explained, she is not a Normal color observer: her color detection system is not operating in the current condition in the way that Mother Nature intended it to operate. His second solution involves the idea that Mother Nature designed our color detection systems to be reliable with respect to the detection of coarse-grained colors (e.g., blue, green, yellow, orange), but our capacity to represent the fine-grained colors (e.g., true blue, blue tinged with green) is an undesigned spandrel. On this second solution, it is consistent with the variation between John and Jane that both represent the color of S in a way that complies with Mother Nature’s intentions: both represent S as exemplifying the coarse-grained color blue, and since (we may assume) S is in fact blue, both represent it veridically. Of course, they also represent fine-grained colors of S, and, according to Tye, at most one of these representations is veridical (Tye says that only God knows which). But at the level of representation for which Mother Nature designed our color detection systems, both John and Jane (qua Normal observers) are reliable detectors.

o (2000), 243). In particular, the idea is that binding interactions between the relevant expressions and natural lan- guage quantifiers are best explained by the hypothesis that those expressions harbor hidden but bindable variables. Recently, however, Herman Cappelen and Ernie Lepore have rejected such binding arguments for the presence of hid- den variables on the grounds that they overgeneralize — that, if sound, such arguments would establish the presence of hidden variables in all sorts of ex- pressions where it is implausible that they exist (Cappelen and Lepore (2005), Cappelen and Lepore (2002)).1 In what follows we respond to Cappelen’s and Lepore’s attempted reductio by bringing out crucial disanalogies between cases where the binding argument is successful and cases where it is not. But we have a deeper purpose than merely to respond to Cappelen and Lepore: we think the attempted reductio goes wrong by not taking sufficiently seriously the nature of the binding relation that holds between quantifiers and arguments/variables, and that our criticism will serve to highlight the nature and importance of this relation.

What is the relationship between sounds and time? More specifically, is there something essentially or distinctively temporal about sounds that distinguishes them from, say, colors, shapes, odors, tastes, or other sensible qualities? And just what might this distinctive relation to time consist in? Apart from their independent interest, these issues have a number of important philosophical repercussions. First, if sounds are temporal in a way that other sensible qualities are not, then this would mean that standard lists of paradigm secondary qualities offered by Locke, Galileo, and other modern philosophers — lists which include colors, odors and sounds without any significant distinctions — overlook significant metaphysical differences. This, in turn, would threaten to undermine the coherence of the modern understanding of secondary qualities itself. Moreover, a number of authors have recently urged that the essential temporality of sounds makes it impossible to understand sounds as properties (except on a trope theory of properties; see note 3). If true, and given the more or less universal view that colors are properties, this last conclusion would make potentially inapplicable to sounds much of the comparatively well-developed philosophical taxonomy and apparatus that has arisen in philosophical disputes over the status of colors (for presentations of this taxonomy and apparatus see, for example, Byrne and Hilbert (2003); Cohen (2008b)).1 Therefore, the conclusion that sounds are distinctively temporal would be a serious blow to hopes for a theoretically unified treatment of the sensory qualities.2 For all these reasons, quite a lot seems to hang on the question of the temporality of sounds.

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)