The author is fully aware of the difficulties connected with an adequate treatment of this subject, in view of the general back­ ground of that fascinating age - the seventeenth century. The present work is simply a modest attempt to draw attention to some in many cases forgotten or disregarded Utopian writings and to show the long line of thought behind many concepts which, to the modern reader, may seem obvious truths. He is very much indebted to Professor H. W. Lambers of Rotterdam for his constant encouragement, help and criticism and also for his willingness to forget for a moment his many other duties and to pass much of his valuable time in the critical study of the seventeenth century papers and publications. The author is very thankful to his mother, his relations and friends both in Holland and in Poland for all they have done for hirn, and he would especially mention Miss Mary Barber for her great help in correcting the English text. He also owes very much to his wife for her patience, coöper­ ation and help in typing the manuscripts. Acknowledgment is made to the Library of the Netherlands School of Economics at Rotterdam, to the Royal Library at The Hague and to the Librarian of the London School of Economics and Political Science for their willing help. J. K. F. CONTENTS v Preface. . .