Book excerpt: An exploration of how the unconscious is formed and functions by one of our most renowned experts on emotion and the brain. This book traces the evolution of the concept of the unconscious from an intangible, metapsychological abstraction to a psychoneurobiological function of a tangible brain. An integration of current findings in the neurobiological and developmental sciences offers a deeper understanding of the dynamic mechanisms of the unconscious. The relevance of this reformulation to clinical work is a central theme of Schore's other new book, Right Brain Psychotherapy.