454 THE QUANTUM THEORYDuring the years 1933-45 Einstein spoke out less on political issues than he
had done before or would do again after the war.* The reasons for this relative
quietude are obvious. In the early years he was not yet a U.S. citizen. When the
war came there was only one issue: to win it. From 1933 until after the war he
desisted from advocating world disarmament and conscientious objection. 'Orga-
nized power can be opposed only by organized power. Much as I regret this, there
is no other way' [N6]. During the war years he acted as occasional consultant to
the Navy Bureau of Ordnance.
Much has been written about Einstein's letters to President Roosevelt on the
importance of the development of atomic weapons [E26]. Opinions on the influ-
ence of these letters are divided.** It is my own impression that this influence was
marginal. It is true that Roosevelt appointed a three-man Advisory Committee on
Uranium on the same day he replied to Einstein's first letter. However, he only
decided to go ahead with full scale atomic weapons development in October 1941.
At that time he was mainly influenced, I believe, by the British efforts. It was not
until then that Secretary of War Stimson heard about the project for the first time
[S2]. In his later years, Einstein himself said more than once that he regretted
having signed these letters. 'Had I known that the Germans would not succeed in
producing an atomic bomb, I would not have lifted a finger' [VI].
The story of Einstein in Princeton will be continued and concluded in Chapter- Before returning to objective reality, I mention one anecdote of Einstein's early
years in the United States, a story I owe to Helen Dukas.
During a speech by a high official at a major reception for Einstein, the honored
guest took out his pen and started scribbling equations on the back of his program,
oblivious to everything. The speech ended with a great flourish. Everybody stood
up, clapping hands and turning to Einstein. Helen whispered to him that he had
to get up, which he did. Unaware of the fact that the ovation was for him, he
clapped his hands, too, until Helen hurriedly told him that he was the one for
whom the audience was cheering.
25c. Einstein on Objective Reality
In his Como address, Bohr had remarked that quantum mechanics, like relativity
theory, demands refinements of our everyday perceptions of inanimate natural
phenomena. 'We find ourselves here on the very path taken by Einstein of adapt-
ing our modes of perception borrowed from the sensations to the gradually deep-
ening knowledge of the laws of Nature' [B5]. Already then, in 1927, he empha-
sized that we have to treat with extreme care our use of language in recording the
results of observations that involve quantum effects. 'The hindrances met with on
this path originate above all in the fact that, so to say, every word in the language
*See [N5] for some of Einstein's opinions during the period 1933-45.
**For comments by General Groves, I. I. Rabi, and E. P. Wigner see [LI].