EDITORIAL METHOD The publication of texts in The Collected Papers is based on the following guidelines for their selection, establishment, presentation, transcription, and annotation. SELECTION All of Einstein's articles, books, and unpublished writings are included in this edition. Only a handful of his notebooks are preserved two of these contain notes on a physics course he took in Zurich and are printed in Volume 1. The remaining notebooks, containing research notes and lecture notes for university courses he taught, will be printed in future volumes. Auditors' lecture notes, verbatim or in abstract, will supplement Einstein's course notes, and reliable records of his lectures, speeches, comments, or interviews will be included. Marginalia by Einstein that contribute significantly to an under- standing of his thought are also included. All available letters written by Einstein will be published in this edition. Letters addressed to more than one recipient are printed only once, and all known addressees are noted. Letters to Einstein are handled more selec- tively, however. All significant letters to him, for which we are able to obtain permission to publish, are printed in whole or in excerpt. In case such per- mission cannot be obtained, a summary is provided. Authors and dates of known letters not published here are listed in the chronological sequence, and the letters are summarized where necessary. Third-party letters and other documents (such as certificates and official reports) that are important for understanding Einstein's development, milieu, and public activity are printed in whole, part, or in summary. Significant con- temporary accretions are published as part of such texts. Authors and dates of known but unavailable items are cited, and any avail- able, important excerpts from the original are printed. ESTABLISHMENT OF TEXTS It is our policy initially to work from a photocopy of a manuscript text, and then to perfect our transcription against the original, if available. If neither