The brain has been viewed as an organ, machine, biological computer, or nervous system component. What are its major parts and how are they interconnected to generate thinking, feelings, and behavior? This book surveys 2,500 years of scientific thinking about these profoundly important questions from the perspective of fundamnetal architectural principles, and proposes a new model for the basic plan of neural systems organization based on an explosion of structural data from the neuroanatomy revolution of the 1970's. It is designed to be read by anyone with an interest in the basic organization of the brain, from neuroscience to philosophy to computer science to molecular biology, and it is suitable for use in neuroscience core courses.