1 1 6 D O C . 1 3 7 O C T O B E R 1 9 1 9 to do so again personally. Once one has understood your theory, it is so convincing that the astronomical result becomes a matter of course: it simply couldn’t have come out otherwise. That is why I understand how you likewise looked upon the measurement of the plates with imperturbable certainty.[3] Even so, the day on which the deflection was experimentally demonstrated is a proud day for you, for physics, indeed for the whole of science and philosophy, to celebrate. In the meantime, I have exchanged a couple of letters with the Zionists. It seems that prospects for a Jewish state are being viewed optimistically, and colonization will make a powerful start with the end of the military administration.[4] The found- ing of the university is being prepared in earnest because, on the one hand, there are high school graduates in need of higher education in Palestine itself. On the oth- er hand, higher education for Jews in Poland involves great difficulties due to anti- Semitism and social boycott. I made it clear to my correspondents that the profes- sorship, which in your hands would have acquired general philosophical signifi- cance, will, with me, sink down to a standard specialty chair, the filling of which is not urgent, since theoretical physics classes are attended only after a few semesters of preliminary studies.[5] Nevertheless, it would be quite preferable to me to enter into relations with the people of influence as early as possible in order, as the case may be, to be able to acquire a good command of the language in the interim. As I hear, Dr. Ruppin will be in Berlin in the next few weeks and contact you about the university issues.[6] Meanwhile, I have carried out the calculations I had once mentioned to you in conversation regarding the dispersion theory from the point of view of quantum theory. The definite outcome is that the Debye-Sommerfeld theory is only of ap- proximative value and that the true theory must introduce the frequency condition in its initial assumption.[7] It is consequently nothing unusual that Sommerfeld’s re- sults are occasionally off.– Last week Debye was here and delivered a fine talk at the Phys. Soc.[8] Please convey my cordial greetings to Ehrenfest, likewise to his wife.[9] With many thanks, I remain with sincere respect, yours truly, Paul Epstein. 137. From Moritz Schlick Rostock, 23 Orléans St., 15 October 1919 Highly esteemed Professor, In the next day or so you will receive an invitation from Rostock University to attend the Quincentennial Jubilee. You will note that the university has more than