D O C S . 2 1 1 – 2 1 3 D E C E M B E R 1 9 1 9 1 8 1 211. To Felix Ehrenhaft Berlin, 14 December 1919 Dear Mr. Ehrenhaft, The invitation by you and the Chemical-Physical Society[1] would have pleased me exceedingly if I had seen the slightest chance of accepting it. But with my un- stable health I shall not be able to undertake either the trip to Basle or to Vienna.[2] I also won’t be able to think of traveling because I do not want to leave my fatally ill mother, who is being brought here in the next day or so.[3] I do not want to ne- glect referring you on this occasion to the highly talented young Viennese, Mr. Pauli, who could be an excellent substitute for me, not even to mention Messrs. Schrödinger and Thirring, who I know have a full command of the chains of rea- soning of the general theory of relativity.[4] In thanking you and the gentlemen of the Chemical-Physical Society deeply for their kind invitation, I am with amicable regards, yours. Please return the greetings from our colleague Lampa most cordially for me.[5] I am honestly sorry that I cannot come. 212. To Hermann Schüller[1] [Berlin,] 14 December 1919 Dear Sir, Judging from your program I think that there would be little point in your visit- ing me.[2] It seems to involve much less a school in which the gifted among the pro- letariat can acquire knowledge and methods of thinking than a propagandistic in- stitute with the aim of implanting sterile hatred. With utmost respect. 213. To The Svedberg Berlin, 14 December 1919 Dear Colleague, I am busy writing an article for Nature that is as good as devoid of formulas.[1] I would be pleased if this article also appeared in the Swedish language. It does, however, presume a certain familiarity with the way of thinking in the exact