Martian Colours

Developmental synesthesia typically involves either the stimulation of one sensory modality which gives rise to an experience in a different modality (when a sound, for example, evokes a colour) or the stimulation of a single sensory modality giving rise to different qualitative aspects of experience (when the sight of a number, for example, evokes a colour). These occurrences seem to support Grice’s (1989) argument that sense modalities cannot be individuated without reference to the introspective-character of experience. This, however, threatens intentionalism which maintains that the qualitative character of experience is exhausted, or fully determined by, its intentional content. Ross (2001) attempts to defuse Grice’s argument by proposing an account that does not appeal to the qualitative character of experience to individuate sense modalities. I argue that his account is unsuccessful.