In this book, I have selected topics that are representative of neuroscience inquiry, retaining brief references to a larger context that includes the study of neurology, anthropology, paleontology, computer science and philosophy. There have been several attempts to develop a "theory" of brain function that incorporates a large collection of observations, experimental results and a growing understanding of the innate features of human nature. I doubt that a single theory is feasible and suggest that the goal is integration of knowledge from diverse disciplines into a comprehensive understanding of who we are and why we are the way we are.