This book traces the emergence of the ideas and institutions that evolved to give people mastery over their own destiny through the force of public opinion. The Greek belief in citizen participation is shown as the ground upon which the idea of public opinion began and upon which it grew. For Wilson, public opinion is always an "orderly force," contributing to social and political life. Wilson appraises the influence of modern psychology, with its techniques and ideas, and the slow and at first scarcely recognized appearance of the methodologies that would enable people not only to measure the opinions of others, but to mold them as well. He examines the relation of the theory of public opinion to the intellectuals, the middle class, and the various revolutionary and proletarian movements of the modern era. He also considers the position of ordinary people, and the circumstances in which the individual may refuse to follow the opinions of the experts are succinctly and movingly analyzed. This book is a historical and philosophical evaluation of a concept that has played a decisive part in history and whose overwhelming force is today most peculiarly underestimated. The author's penetrating insight brings an understanding that is invaluable at a time when public opinion, the very force developed to enable the ruled to restrain their rulers, has become itself controllable and attempts to manipulate it are made by those who would impose their will upon their fellow men.