D O C . 1 7 0 O N O V E R D E T E R M I N A T I O N 2 7 5

attempts at giving tangible form to my pet idea of interpreting quantum structure through an overde-

termination with differential equations refuse to succeed” (“Ich brüte in meiner freien Zeit immer

über das Quantenproblem vom Standpunkt der Relativität. Ich glaube nicht, dass die Theorie das Kon-

tinuum wird entbehren können. Es will mir aber nicht gelingen, meiner Lieblingsidee, die Quanten-

struktur aus einer Überbestimmung durch Differentialgleichungen zu verstehen, greifbare Gestalt zu

geben” Einstein to Max Born, 3 March 1920 [Vol. 9, Doc. 337]). By April 1920, Einstein apparently

had given up on this approach for the time being: “Overdetermination does not work” (“Eine Über-

bestimmung gelingt nicht”; Einstein to Paul Ehrenfest, 7 April 1920 [Vol. 9, Doc. 371]).

[9]The footnote is missing in the manuscript.

[10]After “Range,” the manuscript adds “ den Energietensor des elektromagnetischen Feldes.”

For the case where the energy-momentum tensor is trace-free, as is the case for the electromagnetic

field, the field equations equating the Einstein tensor or the Ricci tensor to the energy-

momentum tensor are equivalent, since the trace-freeness of energy-momentum implies that the

Ricci scalar R must vanish.

[11]In Einstein and Grommer 1923a (Vol. 13, Doc. 12), Einstein had first demanded that field the-

ory should improve on the Einstein-Maxwell equations by generalizing the field equations in such a

way that they would allow for static spherically symmetric solutions that could be interpreted as ele-

mentary electric charges. For details, see Einstein and Grommer 1923a (Vol. 13, Doc. 12), note 9; the

criterion also occurs in Einstein 1923n (Doc. 52). Until now, Einstein had applied the criterion in the

context of the Kaluza-Klein theory and in the context of affine field theory; in the present, program-

matic, document, it appears as one of three necessary but even jointly not sufficient conditions for the

desired theory.

[12]In the manuscript, the passage between “folgende Bedingungen eingeschränkt werden” (in the

line before 1. above) and “mitbestimmt wird” exists also in a slightly different version that was later

deleted.

[13]Apparently, Einstein is citing from the fourth edition (see Weyl 1921, §32).

[14]The Nachtrag (supplement) is missing in the manuscript.

For further historical discussion of this document, see Pais 1982, pp. 464–465; Vizgin 1994,

pp.197–204; Goenner 2004, sec. 4.3.4; and Sauer 2014a, pp. 293–294.

Til

Gil Ril

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