The Düsseldorf conference was, as far the mathematics section is concerned, so uninteresting and insignificant that I took the remaining 10 days to go to Paris for my intellectual refreshment. That, on the other hand, is quite fantastic…I liked Paris so much that I would like to return if it is at all possible. Just in passing, and to annoy you, I also visited Mondrian the painter, who paints only squares. He showed me photos of all his pictures; the development is quite interesting. Also his studio, whose walls are covered with large rectangles in different colours and sizes. I liked it very much.…

From there I returned to Amsterdam after all. I am lecturing on the calculus of variations. Personally, I am occupied by geometry of all kinds, furthermore by epistemology. I hope I'll get the energy to put together my views about the problem of truth. In the last weeks, I have had so many ideas that I don't have any time at all to write them down, and run away every evening to distract myself…in order not to overwork. Apart from that, I curse the fact that I am not in Vienna but rather here. I can't get used to living here, and I will try my best to leave here forever in the month of June.