The sub title indicates the scope of this acute and well ordered study of revolution, in theory and in action. In fact it might be defined as a biography of revolution, the formation of revolutionary ideas, their presentation and their fulfillment. The first third of the book deals with Michelet and his followers, Renan, Taine and France, who were to usher in the decline of enlightenment and of the bourgeois revolution. Paralleling this, socialism developed in inverse proportion, in France and America. The second part of the book is largely devoted to Marx and Engels, who were to attempt to change the world rather than to record and interpret it. The last third deals with Lenin, "headmaster" of Revolution, and through whom "the key of a philosophy of history was to fit an historical lock". Wilson is one of the finest liberal critics of our time -- and this study though not for the general reader, is important as analysis of the progress of the social world, up to a certain point.