Why does the human brain insist on interpreting the world and constructing a narrative? In this ground-breaking work, Michael S. Gazzaniga, one of the world's foremost cognitive neuroscientists, shows how our mind and brain accomplish the amazing feat of constructing our past--a process clearly fraught with errors of perception, memory, and judgment. By showing that the specific systems built into our brain do their work automatically and largely outside of our conscious awareness, Gazzaniga calls into question our everyday notions of self and reality. The implications of his ideas reach deeply into the nature of perception and memory, the profundity of human instinct, and the ways we construct who we are and how we fit into the world around us.