Physical control of the mind by direct manipulation of the brain is a novel event in man's history. In this forty-first volume in World Perspectives Dr. Jose M. R. Delgado describes his pioneer work in implanting electrodes in the brains of cats, monkeys, and men. He shows how, by electrical stimulation of specific cerebral structures, movements can be induced by radio command, hostility may appear or disappear, social hierarchy can be modified, sexual behavior may be changed, and memory, emotions, and the thinking process may be influenced by remote control. Direct nonsensory communication between brains and computers has already been accomplished; and with the aid of miniaturized subcutaneous instruments, messages have been sent to neuronal structures through the intact skin. These discoveries have medical, psychological, sociological, and philosophical implications. The knowledge of brain physiology thus gained can give man more command over himself and his civilizations development to be welcomed, since awareness is our best defense against manipulation. The mind is no longer unreachable, and may be the subject of experimental investigations, We need to reorient the aims of civilization to restore a balance between its physical and psychological evolution. Our present mechanized society is dangerously self-perpetuating, and should be psychocivilized in order to develop wiser minds to control intelligently the awesome technological energy discovered by man. Dr. Delgado believes man's primary objective should be "not the development of machines, but of man himself." He writes lucidly about his work, putting it into the context of what is known about the mind and the brain, and exploring long-range ethical and social implications of his discoveries. The result is an exceedingly important and provocative book.