This book deserves special notice because it represents a type of study that has been very much needed. Public opinion is notoriously elusive, and yet it is clear that it is one of the great factors conditioning the conduct of foreign relations under modern democratic conditions. Professor Carroll has devoted years to a careful analysis of French opinion on foreign affairs and has produced the first scientific treatment of the evolution of popular sentiment in any of the major states of Europe. He has made extensive use not only of newspaper and other periodical literature, but has drawn freely upon the large mass of documentary and other material touching upon the history of pre-war diplomacy. Of course, the material is so voluminous that it can never be completely exhausted. But the author has selected it wisely from a very large and representative range. He has put many disputed points in a new setting, and has, furthermore, written a book which makes fascinating and very instructive reading. It would be a boon to the further study of international relations if books of this sort were written for the other important states of the European system.