This book centers on the major theme of Reinhold Niebuhr's lifework, the nature of man and his political and social life. Idealistic and realistic social philosophies are reevaluated and tribalism is analyzed as a pervasive quality of mankind's societies. A thinker who has always advanced by criticizing his own assumptions, Dr. Niebuhr continues to break new ground and to reconsider some of his earlier judgments. In this book, Dr. Niebuhr reviews the doctrines of the political order advanced by religious and secular interests; he traces the long history of the paradox of man's obvious universal humanity and the tribal loyalties which are the roots of man's inhumanity to man; and he deals with the complex relation between ambition and creativity. Adding to and modifying his remarkable contribution to contemporary thought, Dr. Niebuhr has written a book that is of fundamental importance.