We are pleased to be publishing this translation of selected documents of Volume 9 of The Collected Papers of Albert Einstein, the companion volume to the annotated, original-language documentary edition. As we have stated in all earlier volumes, these translations are not intended for use without the documentary edition, which provides the extensive editorial commentary necessary for a full historical and scientific understanding of the source documents. The translations strive first for accuracy, then literariness, though we hope that both have been achieved. The documents were selected for translation by the editors of The Collected Papers of Albert Einstein. We thank Ann M. Hentschel and Klaus Hentschel for their continuing good work and dedication to making Einstein’s correspondence available to the English-speaking world Elisa Piccio and Michele Valisneri for translating the Italian correspondence Diana Kormos Buchwald for her attention to the translation project and everyone else at the Einstein Papers Project for their practical input: Rosy Meiron for stylistic suggestions, and Osik Moses for indexing, typesetting the manuscript, and producing the camera-ready copy, assisted by József Illy, Rudy Hirschmann, and Linny Schenck. Many thanks to Alice Calaprice for her thorough copyediting of the manuscript. Finally, we are most grateful to the National Science Foundation, Grant No. SBR-9710507, for its support of our project. Princeton University Press September 2004 PUBLISHER’S FOREWORD