Do you dream in color? If you answer Yes, how can you be sure? Before you recount your vivid memory of a dream featuring all the colors of the rainbow, consider that in the 1950s, researchers found that most people reported dreaming in black and white. In the 1960s—when most movies were in color and more people had color television sets—the vast majority of reported dreams contained color. The most likely explanation for this, according to philosopher Eric Schwitzgebel, is not that exposure to black-and-white media made people misremember their dreams. It is that we simply don’t know whether or not we dream in color. In Perplexities of Consciousness, Schwitzgebel examines various aspects of inner life—dreams, mental imagery, emotions, and other subjective phenomena—and argues that we know very little about our stream of conscious experience. In fact, he contends, we are prone to gross error about our ongoing emotional, visual, and cognitive experiences.

Western philosophical tradition is nearly unanimous on the accuracy of our knowledge or current conscious experience. Schwitzgebel is skeptical. Drawing broadly from historical and recent philosophy and psychology to examine such topics as visual perspective, human echolocation (about which he is doubtful), and the unreliability of introspection even about emotional states (do we really enjoy Christmas? a family dinner?), he finds us singularly inept in our judgments about conscious experience.