Structural realism for secondary qualities

This paper outlines and defends a novel position in the color realism debate, namely structural realism. This position is novel in that it dissociates the veridicality of color attributions from the claim that physical objects are themselves colored. Thus, it is realist about color in both the semantic and epistemic senses, but not the ontic sense. The generality of this position is demonstrated by applying it to other \secondary qualities," including heat, musical pitch, and odor. The basic argument proceeds by analogy with the theory of measurement. I argue that perceptual experiences are analogous to numerical structures in that they are suitable for measurement, but only report measured values after they have been linked to states of a measurement device via calibration. Since the calibration of our sensory apparatus varies with context, it is inappropriate to identify specic experiences with specic properties in the world. Rather, it is structural relations between possible experiences which represent relations between possible external properties, and it is at the level of these structural relationships that veridicality is appropriately assessed.