CERTAIN portions of this volume on the Position of Foreign States before National Courts have already been published in three separate studies covering the German, French and Belgian material respectively. These studies appear here in an amplified form, in their place among material relative to other states of Europe.
In expressing my thanks to those who have helped me in the preparation of this work, I wish especially to mention the members of the Committee of the Bureau of International Research of Harvard University and Radcliffe College, under whose auspices this book is published, and particularly its chairman, Professor George Grafton Wilson. To another member of this Committee, Professor Manley O. Hudson, Director of the Research in International Law of the Harvard Law School, I am indebted for the privilege of participating in the work of the Committee on the Competence of Courts in Regard to Foreign States. The meetings of this committee, extending over some two years, were not only a great stimulus in the preparation of this book, but served to keep constantly in the writer's mind the great variety of possible approaches to the subject and the conflicting points of view even of those devoting their attention to the subject as experts.
Thanks are also due to numerous other persons who at one time or another have helped with criticism or suggestion. Among these are Richard W. Hale, Esquire, for assistance in the matter of legal terminology, Professor Maurice Bourquin, lately of the University of Brussels, Professor J. H. W. Verzijl, of the University of Utrecht, Professor Georges Ripert of the Faculty of Law of the University of Paris, who have each been kind enough to read certain portions of the text, and to