Talking About and Seeing Blue

Abstract

Categorical perception is a pervasive and useful feature of human experience much neglected by philosophers despite illuminating psychological research on this topic. The findings of this research on categorical perception are relevant to the truth of basic claims about which properties humans can perceptually experience and they bear on the validity of arguments about the nature of perception. Focusing on the case of colour, this talk reviews some of the key evidence for categorical perception and extracts a characterisation. Together with findings about the development of categorical perception of colour and its complex relations to the use of verbal labels for colour categories, this provides a basis for rejecting what Frank Jackson calls a "subject-determining platitude", namely that "'red' denotes the property of an object putatively presented in visual experience" (Jackson 1996: 200). Categorical perception of colour differs from other forms of perception with respect to phenomenology and epistemology. Seeing blue or red, unlike seeing the particular colours of things, does not involve the presentation in visual experience of a property.