In the letter quoted here, Philipp Lenard, anti-Semite and advocate of a so-called “German physics,” constructs an image of the enemy for what became known as the “Einstein circle.”

Lenard had started his agitation against Einstein and his theories right after World War I.

Together with Johannes Stark he attempts to expose the theory of relativity as a fraud. However, the influence of both men declines in the late 1930s.