An Anthropologist on Mars: Seven Paradoxical Tales

by Oliver Sacks

It was not just that colors were missing, but that what he did see had a distasteful, “dirty” look, the whites glaring, yet discolored and off-white, the blacks cavernous—everything wrong, unnatural, stained, and impure.

These demonstrations, overwhelming in their simplicity and impact, were color “illusions” in Goethe’s sense, but illusions that demonstrated a neurological truth—that colors are not “out there” in the world, nor (as classical theory held) an automatic correlate of wavelength, but, rather, are constructed by the brain.

For we, born with a full complement of senses, and correlating these, one with the other, create a sight world from the start, a world of visual objects and concepts and meanings. When we open our eyes each morning, it is upon a world we have spent a lifetime learning to see.