Freiburg 1921–1953

Abstract

In October 1921, some months after his 50th birthday, Zermelo moved to Freiburg im Breisgau in southwestern Germany, where he subsequently lived for more than three decades until his death in 1953. The mid-1920s saw a resumption of his scientific activity in both applied mathematics and set theory. Furthermore, they provided the opportunity to lecture at the University of Freiburg as an honorary professor. However, the mid-1930s brought a change. As his foundational work was directed against the mainstream shaped by inspired members of a new generation such as Kurt G¨odel and John von Neumann, Zermelo ended up in a kind of scientific isolation and also in opposition to his mentor David Hilbert. As his political views disagreed with the Nazi ideology, he lost his honorary professorship. Thus in 1935 the promising new beginning came to an end which left him in deep disappointment and led him to a life of seclusion. His last years were brightened by his wife Gertrud whom he had married in 1944.