1921
This listing, with abstracts of documents, consists of six elements: (1) All those known let-
ters from and to Einstein (or those written or received by his secretary, Ilse Einstein) that
fall within this period and are excluded from the selection of texts on grounds explained in
the Editorial Method. Variants of documents that are presented as texts do not appear in the
Calendar, nor do drafts that differ insignificantly from final versions that are presented. (2)
Letters written to the Kaiser Wilhelm Institute of Physics (KWIP) board of directors and
board of trustees, and to the administration of the Kaiser Wilhelm Society (KWG), as well
as third-party documentation of Einstein’s role as director of the KWIP, references to pub-
lic activities, and his participation in the Prussian Academy of Sciences (PAW). No attempt
is made, however, to document Einstein’s mere attendance at class or plenary sessions (for
a record of his attendance, see Kirsten and Treder 1979, pp. 207–286), nor his acknowledg-
ment of the actions of other members of the PAW. Records of preliminary procedural stag-
es in administrative matters of more substantial calendar items, as well as subsequent pro-
cedural stages when no feedback is requested, are also excluded. (3) References to Ein-
stein’s writings that appear in the Writings series of the edition. In the case of published
papers, the date refers to receipt by a journal, unless indicated otherwise, such as submis-
sion dates to the PAW. (4) Interviews with Einstein. No attempt is made, however, to in-
clude newspaper articles in which excerpts from earlier interviews or significant citations
therein are republished, nor material from interviews that is expanded and worked into a
monograph. (5) References to significant events in Einstein’s life, as well as significant po-
litical events. (6) Aphorisms and signed dedications by Einstein, and signed dedications to
Einstein by authors of books and articles.
If only an archival number in square brackets is given at the end of an entry, the source is
the Albert Einstein Archives at the Hebrew University in Jerusalem. Otherwise, the
location of the original follows each entry. If the location is unknown, the source of the
photocopy or transcript used is given. Symbols for documentary repositories follow the au-
thorities guidelines in The Library of Congress National Union Catalog of Manuscript
Collections and its MARC Code List for Organizations.
Newspaper titles without date refer to the issue published on the date of the entry.
CALENDAR