PLANCK, Max (1858-1947). Autograph letter signed ("M. Planck") to an unidentified church official ("Oberkirchenrat"), Berlin-Grunewald, 5 February 1941.

In German. Two pages, 210 x 148mm (slight tear at right margin affecting one word on verso, two neat file holes along right margin, just grazing two words on verso).

Planck on Nazi attacks on Einstein and the theory of relativity: "This attack on a scientific theory for popular political reasons has always had something ridiculous for me…." The German physicist belittles Nazi efforts to discredit Einstein's theory of relativity: "Regarding this question, it should be noted that only a tiny number of physicists have opposed the theory of relativity, although this has been all the louder, and mainly in popular newspapers. This attack on a scientific theory for popular political reasons has always had something ridiculous for me…" But he goes on to reveal his own antisemitism, adding that the attacks are "only explicable by justifiable anger at the disgustingly public way in which a Jewish clique around Einstein took up the word 'relative' and misused it for purposes unrelated to physics. But the attack by a few physicists on the scientific theory of relativity, which has become fundamental to science today, was absolutely unjustified." A daring statement made during a period of extreme political repression, Planck both criticizes attacks borne of antisemitism, while engages in antisemitism himself.

Einstein and Planck were close professionally and personally, often playing music together while they were colleagues at the University of Berlin. When the Nazis came to power in 1933, Planck appealed to Hitler personally asking him to stop expelling Jewish scientists as German science would suffer for it—but the appeal was ignored. Soon Planck himself became the target of Johannes Stark who criticized him, Heisenberg, and others for continuing to teach Einstein's theories. When the Prussian Academy was taken over by the Nazis in 1938, Planck resigned in protest. During the course of the war, his house in Berlin was destroyed in an air raid, and his son, Erwin, was implicated in the plot to assassinate Hitler. Erwin was subject to a show trial and executed in January 1945—a devastating blow that destroyed much of Planck's will to live. Planck died in October 1947.