NOUSˆ 54:2 (2020) 290–326 doi: 10.1111/nous.12245
Perceptual Variation and Structuralism
JOHN MORRISON Barnard College, Columbia University
I use an old challenge to motivate a new view. The old challenge is due to variation in our perceptions of secondary qualities. The challenge is to say whose percep- tions are accurate. The new view is about how we manage to perceive secondary qualities, and thus manage to perceive them accurately or inaccurately. I call it perceptual structuralism. I first introduce the challenge and point out drawbacks with traditional responses. I spend the rest of the paper motivating and defending a structuralist response. While I focus on color, both the challenge and the view generalize to the other secondary qualities.
1. Perceptual Variation
Our perceptual experiences tell us that lemons are yellow and sour. It’s natural to infer that lemons really are yellow and sour. But perceptions vary, even among ordinary observers. Some perceive lemons as slightly greener and sweeter. This gives rise to a challenge that forces us to rethink the nature of perception and the objectivity of what we perceive. For concreteness, I’ll focus on the perceptions of two ordinary observers, Miriam and Aaron. I’ll also focus on their perceptions of a particular lemon’s color. These restrictions will make the challenge easier to understand and the responses easier to compare. But the challenge and responses are perfectly general. Toward the end of the paper I’ll return to sourness and the other secondary qualities. When Miriam and Aaron look at the same lemon, their perceptions differ. I think the best way to convey how their perceptions differ is to use your perceptions as a reference point. Let phenomenal-greenish-yellow be the phenomenal character of your perception when you report that a surface looks greenish yellow, and phenomenal-pure-yellow be the phenomenal character of your perception when you report that a surface looks unmixed, pure yellow under the same viewing conditions. Suppose that Aaron’s perception of the lemon is phenomenal-greenish-yellow, and Miriam’s perception of the lemon is phenomenal-pure-yellow. Who is accurately perceiving the lemon’s shade, Miriam or Aaron? There are four responses: neither, one, both, and indeterminate. These re- sponses are traditionally developed: neither of them is accurately perceiving the lemon’s shade, because the lemon isn’t colored; one of them is accurately perceiv- ing the lemon’s shade, because they’re perceiving incompatible shades, such as pure