EDITORIAL METHOD OF THE SERIES The following presents the editorial method of the series and incorporates modifi- cations and supplements that have been introduced in previous volumes. HISTORY OF THE EDITION Volume 1, The Early Years, 1879–1902, presented a variety of documents pertain- ing to Albert Einstein’s family, childhood, and youth. Subsequently, the edition was divided into two series, Writings and Correspondence. The five Writings volumes covering the years 1900–1921 (volumes 2–4, 6, 7) present in full text all of Einstein’s articles, books, and unpublished scientific man- uscripts, including his notes as a student of physics, lecture notes for university courses that he taught, and research notes. Auditors’ lecture notes, verbatim or in abstract, that supplement Einstein’s course notes, as well as reliable records of his lectures, speeches, comments, or interviews, are included as full text or in abstract. All available letters written by Einstein before January 1922 are presented in full or as abstracts in the six Correspondence volumes for the years 1902–1921 (volumes 5, 8–10, 12). A Cumulative Index, Bibliography, List of Correspondence, Chronology, and Errata to Volumes 1–10 was published as Volume 11. Beginning with the current volume, the edition will present Einstein’s writings and correspondence together in the same volumes, in chronological order. This for- mat will facilitate a contextual understanding of Einstein’s life and work. SELECTION All of Albert Einstein’s writings and correspondence, whether previously pub- lished or unpublished, are included in the edition, either as full text with annotation, as an appendix, or as an abstract. Prefaces to collective editions in whose composition Einstein took an active part are printed in full. Einstein’s prefaces to works other than his own, or to translations of his own work, are generally presented in abstract.