Psychology has had some success in describing personality differences, but the picture often appears incomplete, and it has been hard to find links between personality and the organization of the brain. Using vivid case-histories and an in-depth questionnaire, this book proposes a broad and eminently new way of looking at individual differences. Boundaries, according to the author, pervade our lives - separating inner from outer experience, past from present, and sleeping from waking. The concept applies to both normal and abnormal behaviour, to relationships, attitudes, and states of mind and body. This book explains how boundary types originate, how and why they may change, and how an understanding of this concept can help us better understand and control our emotional lives. Ernest Hartmann is the author of The Nightmare and The Functions of Sleep.