This is Robert Fried’s third book on the crucial role of breathing and hyperventilation in our emotional and physical health. The first, The Hyperventilation Syndrome (1987), was a scholarly monograph, and the second, The Breath Connection (1990a), was a popular version for the lay reader. This book combines the best features of both and extends Dr. Fried’s seminal work to protocols for clinical psychophysiology and psy chiatry. Hoping to avoid misunderstanding, he has taken systematic care to introduce relevant electrical, physiological, and psychological concepts in operational language for the widest possible professional audience. Any clinician not thoroughly experienced in respiratory psycho physiology and biofeedback will leave these pages with profound new insight and direction into an aspect of our liveswhich we innocently take for granted as common sense -the role of breathing in health and illness. Einstein viewed such common sense as that set of prejudices we acquired prior to the age of eighteen. I am impressed that Dr. Fried mirrors Einstein’s uncanny genius in not accepting the obvious breathing is not common sense but, rather, is a pivotal psycho physiological mechanism underlying all aspects of life.