A common view in both philosophy and the vision sciences is that, in human vision, wavelength information is primarily ‘for’ colouring: for seeing surfaces and various media as having colours. In this article we examine this assumption of ‘colour-for-colouring’. To motivate the need for an alternative theory, we begin with three major puzzles from neurophysiology, puzzles that are not explained by the standard theory. We then ask about the role of wavelength information in vision writ large. How might wavelength information (...) be used by any monochromat or dichromat and, finally, by a trichromatic primate with object vision? We suggest that there is no single ‘advantage’ to trichromaticity but a multiplicity, only one of which is the ability to see surfaces and so on as having categorical colours. Instead, the human trichromatic retina exemplifies a scheme for a general encoding of wavelength information given the constraints imposed by high spatial resolution object vision. Chromatic vision, like its partner, luminance vision, is primarily for seeing. Viewed this way, the ‘puzzles’ presented at the outset make perfect sense. 1 Reframing the Problem1.1 Introduction1.2 Three puzzles1.2.1 Why is trichromatic vision an anomaly in diurnal mammals?1.2.2 Why does the colour system occupy such a large and central part in human vision?1.2.3 Why are the blue cones so rare?1.3 Recasting the question2 The Costs and Benefits of Spectral Vision2.1 Spectral information and object vision2.2 Encoding the spectral dimension of light2.2.1 ‘General’ versus ‘specific’ encoding2.2.2 Spectral encoding and the monochromat2.2.3 Spectral encoding and the dichromat2.2.4 Spectral encoding and the human trichromat2.3 Three puzzles revisited2.3.1 Why is trichromatic vision an anomaly in diurnal mammals?2.3.2 Why does the colour system occupy such a large and central part in human vision?2.3.3 Why are the blue cones so rare3 Conclusion. (shrink)

Deviant phenomenal knowledge is knowing what it’s like to have experiences of, e.g., red without actually having had experiences of red. Such a knower is a deviant. Some physicalists have argued and some anti-physicalists have denied that the possibility of deviants undermines anti-physicalism and the Knowledge Argument. The current paper presents new arguments defending the deviant-based attacks on anti-physicalism. Central to my arguments are considerations concerning the psychosemantic underpinnings of deviant phenomenal knowledge. I argue that physicalists are in a superior (...) position to account for the conditions in virtue of which states of deviants constitute representations of phenomenal facts. (shrink)

The goal of the present paper is to defend against a certain line of attack the view that conscious experience of color is no more fine-grained that the repertoire of non- demonstrative concepts that a perceiver is able to bring to bear in perception. The line of attack in question is an alleged empirical argument - the Diachronic Indistinguishability Argument - based on pairs of colors so similar that they can be discriminated when simultaneously presented but not when presented across (...) a memory delay. My aim here is to show that this argument fails. (shrink)

s Gibson (1982) correctly points out, despite Quine’s brief flirtation with a “mitigated phenomenalism” (Gibson’s phrase) in the late 1940’s and early 1950’s, Quine’s ontology of 1953 (“On Mental Entities”) and beyond left no room for non-physical sensory objects or qualities. Anyone familiar with the contemporary neo-dualist qualia-freak-fest might wonder why Quinean lessons were insufficiently transmitted to the current generation.

Any satisfactory model of the emotions must at once recognize their place within intentional psychology and acknowledge their uniqueness as mental causes. In the first half of the century, the James-Lange model had considerable influence on reinforcing the idea that emotions are non-intentional (see Lange 1885 and James 1890). The uniqueness of emotions was therefore acknowledged at the price of denying them a place within intentional psychology proper. More recently, cognitive reductionists (including identity theorists) like Robert Solomon and Joel Marks (...) recognize that emotions are intentional but, by reducing them to judgments, beliefs, desires, etc., fail to capture their distinctiveness as mental causes (see Solomon 1976 and Marks 1982). In other words, their place within intentional psychology is acknowledged at the price of denying them their uniqueness. (shrink)

Mandik (2012)understands color-consciousness conceptualism to be the view that one deploys in a conscious qualitative state concepts for every color consciously discriminated by that state. Some argue that the experimental evidence that we can consciously discriminate barely distinct hues that are presented together but cannot do so when those hues are presented in short succession suggests that we can consciously discriminate colors that we do not conceptualize. Mandik maintains, however, that this evidence is consistent with our deploying a variety of (...) nondemonstrative concepts for those colors and so does not pose a threat to conceptualism. But even if Mandik has shown that we deploy such concepts in these experimental conditions, there are cases of conscious states that discriminate colors but do not involve concepts of those colors. Mandik’s arguments sustain only a theory in the vicinity of conceptualism: The view that we possess concepts for every color we can discriminate consciously, but need not deploy those concepts in every conscious act of color discrimination. (shrink)

It’s often held that undetectable inversion of mental qualities is, if not possible, at least conceivable. It’s thought to be conceivable that the mental quality your visual states exhibit when you see something red in standard conditions is literally of the same type as the mental quality my visual states exhibit when I see something green in such circumstances. It’s thought, moreover, to be conceivable that such inversion of mental qualities could be wholly undetectable by any third-person means. And since (...) first- person access is limited to a single individual, and so could not reveal a disparity in mental quality between us, third-person undetectability means undetectability tout court. (shrink)

Forthcoming in Philosophical Issues, vol 18, Interdisciplinary Core Philosophy: The Metaphysics and Perception of Qualities. Alex Byrne & David Hilbert, section editors.

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)

1. My primary aim in this paper is to set the stage for a discussion of some of the central themes in the so-called "identity" approach to the mind-body problem. I have particularly in mind Herbert Feigl's elaborate statement and defense of this approach in Volume II of the Minnesota Studies. A secondary, but more constructive, purpose is to bring out some of the reasons which incline me to think that the theory is either very exciting but false, or true (...) but relatively uninteresting. (shrink)

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. (shrink)

Most materialist responses to the zombie argument against materialism take either a “type-A” or “type-B” approach: they either deny the conceivability of zombies or accept their conceivability while denying their possibility. However, a “type-Q” materialist approach, inspired by Quinean suspicions about a priority and modal entailment, rejects the sharp line between empirical and conceptual truths needed for the traditional responses. In this paper, I develop a type-Q response to the zombie argument, one stressing the theory-laden nature of our conceivability and (...) possibility intuitions. I argue that our first-person access to the conscious mind systematically misleads us into thinking that the distinctive qualities of conscious experience—qualia—are nonfunctional. Qualia, I contend, are functional, even though they do not seem to be. To support my claim, I introduce the “meditations” of Rene Descartes’ zombie twin. This establishes the plausibility of an appearance/reality distinction for consciousness and it undermines various anti-materialist objections based on privileged first-person access. I conclude that the best overall theory posits an appearance/reality distinction for qualia, and this, for the type-Q materialist, is decisive. (shrink)