4 6 2 D O C . 3 1 8 C R I S I S O F T H E O R E T I C A L P H Y S I C S Published in Kaizo 4, no. 12 (December 1922): 1–8. Dated August 1922. Two fragments of its manuscript [36 426] are also available. [1]The original title of the manuscript, “Über die Krise der Licht-Theorie,” was changed to the present one by interlineation of “gegenwärtige” and deletion of “Licht-Theorie.” [2]Einstein makes a similar remark about the axiomatic character of physical theory in Einstein 1922i (Doc. 220). [3]In Einstein 1920j (Vol. 7, Doc. 38), Einstein similarly identifies the ether with properties of space. [4]See, e.g., Hertz 1889 and 1892. [5]For earlier expressions by Einstein on the methods and results of field theory as constituting a “revolution” (‘‘Umwälzung’’) in the foundations of physics, see, e.g., Einstein 1914o (Vol. 6, Doc. 9), p. 122. [6]Einstein refers here to the so-called electromagnetic program, the attempt to reduce mechanics to electromagnetic theory. For a clear statement of the research program, see Wien 1900, p. 502 for historical discussions, see Kragh 1999, chap. 9 McCormmach 1970 and Jungnickel and McCorm- mach 1986, pp. 227–245. [7]See Thomson 1881, Abraham 1902. [8]For an explicit reminiscence by Einstein on the genesis of the special and general theories of rel- ativity, see Doc. 399. [9]See Einstein 1921c (Vol. 7, Doc. 52) for a discussion of Einstein’s philosophy of geometry in the wake of relativity theory. [10]Almost exactly the same statement can be found in Einstein’s King’s College Lecture of 1921, namely that general relativity is “apparently” a “completion” (“Abschluss”) of the field-theoretic pro- gram which had been introduced by Faraday and Maxwell (Vol. 7, Doc. 58, p. 431.) [11]See Planck 1900. [12]See Einstein 1907a (Vol. 2, Doc. 38). [13]See Einstein 1905i (Vol. 2, Doc. 14). [14]Einstein 1922l (Doc. 231), p. 828, gives details on the experiment he refers to in the current doc- ument. [15]In the last paragraph of the present document, Einstein comes back to the question of whether field theory can serve as a foundation for physics by discussing the suitability of differential equations (see note 19). [16]See in particular Rutherford 1906 and Bohr 1913. For a comprehensive treatment of the histor- ical development of quantum theory, see Mehra and Rechenberg 1982. [17]The works Einstein has in mind probably include Bohr 1913, Sommerfeld 1916a and 1916b, Epstein 1916, and Schwarzschild 1916. [18]See Epstein 1916. [19]Einstein voiced such doubts in Einstein to Walter Dällenbach, 15 February 1917 (Vol. 8, Doc. 299). Stachel 1993 speaks of “the two Einsteins” when providing a historical discussion of the two incompatible programs of seeking a foundation for physics either by field-theoretical methods (using a continuous manifold and partial differential equations) or seeking a more algebraic founda- tion to account for the discrete phenomena of quantum theory.