itself the American transplant of the Vienna Circle, and we were repeatedly honored by encouragement and participation of the Institute's central figure, Philipp Frank. The proceedings were selected, edited, revised in the light of the discussions at our colloquia, and then other volumes were added which were derived from other symposia, in Boston or elsewhere. A friendly autonomy, in­ dependent of the Synthese Library proper, existed for more than a decade and then the Boston Studies became fully separate. We were grateful to Jaakko Hintikka for his continued encouragement within that Library. The series Boston Studies in the Philosophy of Science was conceived in the broadest framework of interdisciplinary and international concerns. Natural scientists, mathematicians, social scientists and philosophers have contributed to the series, as have historians and sociologists of science, linguists, psychologists, physicians, and literary critics.