In his latest book this well-known author is concerned less with the discovery and communication of new viewpoints than with stressing our inability or failure to make proper use of existing knowledge in ordering our social relationships. The peoples of the world follow aims and apply policies without realizing that they imply war. These "unseen assassins" must be brought to the ken of the average man before real progress can be made towards peace. The author's problem, then, is primarily an educational one, and his book is an examination of the ways and means by which the dangerous implications of the doctrines of sovereignty, nationalism, etc., can be brought within the range of everyday consciousness. The book is one of the most important of recent months and should be widely read.