relevant to his task, as well as having the ability and penetration of mind without which no knowledge could be effective. Moreover, all his discussions, and not least those which deal with matters of acute political controversy, are characterized by the caution and fairness which we have learnt to expect from him and which are essential to the scientific treatment of the very various topics with which they deal. For all these reasons the careful reader, whether he is a plain man or a sociologist and whatever he supposes sociology to be, cannot fail to find in the book much that is of interest and value. 0. DE SELINCOURT.