Qualia Change and Colour Science

The Philosophical Quarterly, 2006

A dual referent approach to colour theory maintains that colour names have two intended, equally legitimate referents. For example, one might argue that 'red' refers both to red appearances or qualia, and also to the way red objects reflect light, the spectral surface reflectance properties of red things. I argue that normal cases of perceptual relativity can be used to support a dual referent approach, yielding an understanding of colour whose natural extension includes abnormal cases of perceptual relativity. This contrasts with Peacocke's multi-referent view, according to which such abnormal cases force us to introduce a wholly distinct kind of colour experience. I also argue that the two uses of colour names, arising from their two referents, have different extensions, even in normal perceptual circumstances, a consequence which conflicts with the heart of Rosenthal's dual referent view.

Stance: An International Undergraduate Philosophy Journal, 2019

For A. J. Ayer, the occurrence of delusions confutes the notion that we perceive the world directly. He argues instead that perceptions are caused by immaterial "sense data" which somehow represent the properties of material things to us in our experiences. J. L. Austin systematically rejects Ayer's claims, arguing that the occurrence of delusions does not preclude the possibility of direct perception, and that, indeed, our normal perception is direct. I challenge both philosophers' ideas by examining how they deal with the phenomenon of colour.

Physicalism about colour is the thesis that colours are identical with response-independent, physical properties of objects. I endorse the Argument from Structure against Physicalism about colour. The argument states that Physicalism cannot accommodate certain obvious facts about colour structure: for instance, that red is a unitary colour while purple is a binary colour, and that blue resembles purple more than green. I provide a detailed formulation of the argument. According to the most popular response to the argument, the Physicalist can accommodate colour structure by explaining it in terms of colour experience. I argue that this response fails. Along the way, I examine other interesting issues in the philosophy of colour and colour perception, for instance the relational structure of colour experience and the description theory of how colour names refer.

Color relationalism, ordinary illusion, and color incompatibility

Relationalism is a view popularized by Cohen according to which the colors are relational properties. Cohen’s view has the unintuitive consequence that the following propositions are false: (i) no object can be more than one determinate or determinable color all over at the same time; (ii) ordinary illusion cases occur whenever the color perceptually represented conflicts, according to (i) above, with the object’s real color; and (iii) the colors we perceive obey (i). I investigate Cohen’s attempt to address these intuitive propositions with which his view struggles and find it to be incompatible with how he motivates his view.

dialectica, 2006

Despite the fact about colour, that it is one of the most obvious and conspicuous features of the world, there is a vast number of different theories about colour, theories which seem to be proliferating rather than decreasing. How is it possible that there can be so much disagreement about what colours are? Is it possible that these different theorists are not talking about the same thing? Could it be that more than one of them is right? Indeed some theorists, e.g. Leo M. Hurvich, D. L. McAdam and K. Nassau, say that the term 'colour' is used to identify a range of different properties, e.g. pigments, properties of light, and sensations. Such a view has its attractions, but it raises the question of what it is that unites these various concepts-what is it that would make them all concepts of colour ? What is it that justifies using the same terms, 'yellow', 'blue', 'pink', mauve', and so on? This paper aims to address this question, arguing that its answer supports the conclusion that the best theory of colour is a form of anti-realism: the Illusory theory of colours. There are two parts to this thesis, one negative, the other positive. The negative part is that there are no colours, as they are ordinarily conceived. The positive part is that, nevertheless, the world is such that 'it is as if there are such colours'. Such a theory has important implications. One is that it doesn't fall neatly into the usual taxonomy of philosophical theories. In particular, it does not deserve the label 'eliminativist'. Another is that it allows some space for the views expressed by Hurvich, McAdam and Nassau, but not quite in the sense that they intend. Colour, on the face of it, is one of the most obvious and conspicuous and unmissable features of the world. The visual world, the world we see, is a world populated by coloured objects: it is a world with a rich tapestry of colours. Despite this fact about colour, however, there are a vast number of different theories about colour, theories that seem to be proliferating rather than decreasing. How is it possible that there can be so much disagreement about what colours are? Is it possible that these different theorists are not talking about the same thing, and that the opposition is more apparent than real? Could it be that more than one of them is right? Leo M. Hurvich begins the second chapter of his Color Vision by first asking 'What is color?' and then asking a series of questions: Is colour something that inheres in objects themselves? Is it related to the light falling on an object? Is it a photochemical event that occurs in the receptor layer of the eye? Is it a neural brain-excitation process? Is it a psychical event? Hurvich's answer is 'Color is all these things'. 1 1 Hurvich 1981, 2.

A standard view in philosophy of mind is that qualia and phenomenal character require consciousness. This paper argues that various experimental and clinical phenomena can be better explained if we reject this assumption. States found in early visual processing can possess qualitative character even though they are not in any sense conscious mental states. This non-standard interpretation bears the burden of explaining what must be added to states that have qualitative character in order to yield states of sensory awareness or sensory experience. I argue that the study of selective attention reveals resources that can be useful in that project. Two traditional objects are briefly considered. organizing the color science conferences and the resulting volume of papers, and for providing very useful comments to me on this particular paper as well. Thanks also go to Valtteri Arstila, Murat Aydede, Steven Biggs, and Alex Byrne, who provided comments on versions of this paper, as well as to audiences at the University of Toronto, Harvard University, the University of British Columbia at Vancouver, Simon Fraser University, and Rutgers University, where versions of these ideas were presented. 1 My notes indicate that the first question Larry Hardin posed was "Why should there be any color experience at all, rather than just information processing?" The question listed above came second, as a followup and elucidation of this first one.

We discuss two modal claims about the phenomenal structure of color experiences: (i) violet experiences are necessarily experiences of a color that is for the subject on that occasion phenomenally composed of red and blue (the modal claim about violet) and (ii) no subject can possibly have an experience of a color that is for it then phenomenally composed of red and green (the modal claim about reddish green). The modal claim about reddish green is undermined by empirical results. We discuss whether these empirical results cast doubt on the other modal claims as well. We argue that this not the case. Our argument is based on the thesis that the best argument for the modal claim about violet is quite different from the best argument for the modal claim about reddish green. To argue for this disanalogy we propose a reconstruction of the best available justification for both claims.

Erkenntnis, 2010

One reason philosophers have addressed the metaphysics of color is its apparent relevance to the sciences concerned with color phenomena. In the light of such thinking, this paper examines a pairing of views that has received much attention: color physicalism and externalism about the content of perceptual experience. It is argued that the latter is a dubious conception of the workings of our perceptual systems. Together with flawed appeals to the empirical literature, it has led some philosophers to grant color physicalism a scientific legitimacy it does not merit. This discussion provides a useful entry into broader points pertaining to debates about color realism and the relationship between philosophical theories of color and the relevant empirical literatures. A sketch of a novel form of color realism is offered, as is an example that fills in some details of that sketch.

Journal of Imaging, 2018

In this work, through a phenomenological analysis, we studied the perception of the chromatic illusion and illusoriness. The necessary condition for an illusion to occur is the discovery of a mismatch/disagreement between the geometrical/physical domain and the phenomenal one. The illusoriness is instead a phenomenal attribute related to a sense of strangeness, deception, singularity, mendacity, and oddity. The main purpose of this work is to study the phenomenology of chromatic illusion vs. illusoriness, which is useful for shedding new light on the no-man's land between "sensory" and "cognitive" processes that have not been fully explored. Some basic psychological and biological implications for living organisms are deduced.