The Secret Life of Numbers: 50 Easy Pieces on How Mathematicians Work and Think (2006)
Chapter: 15 The Unpaid Professor
15
The Unpaid Professor
In the year 1934 the sad circumstances in Germany led to good fortune for Zurich. Because of his Jewish background, the mathematician Paul Bernays was forced to move from Göttingen to the city on the river Limmat. His reputation as a brilliant logician preceded him. Born as a Swiss in London in 1888, Bernays first studied engineering, then mathematics, in Berlin. The young doctor then went on to teach for five years as a Privatdozent—an unpaid assistant professor—at the University of Zurich.
One day the famous mathematician David Hilbert visited Zurich. During a walk with Swiss colleagues through the hills surrounding the city, he became aware of the talented Bernays and immediately offered him a position in Göttingen. Though the Privatdozent was already in his 30s, he did not consider it beneath his honor to move to Göttingen as an assistant to the great Hilbert. The extremely fruitful collaboration culminated in the two volumes of Foundations of Mathematics, in which the authors built the edifice of mathematics, based completely on symbolic logic.
But the brown clouds of the Nazi regime had gathered on the horizon. The mathematical teaching staff in Göttingen, which to a good part consisted of men (and a single woman, Emmy Noether) of Jewish faith, were chased away by Hitler’s henchmen. Hilbert was dejected about the departure of Bernays, as well as that of all his other Jewish colleagues.
Göttingen’s loss was Zurich’s gain, since Bernays’s arrival seeded the beginning of the flowering of logic in Switzerland. At the Eidgenössische Technische Hochschule, he was first a lecturer and then an adjunct professor with half a teaching load. Together with Ferdinand Gonseth and George Polya, Bernays conducted the first seminar in logic during the winter semester of 1939–1940. It was to
become a staple on the academic calendar; Bernays organized and led it for decades. Attendance at the seminar was free. Bernays, not being a full-time employee of the university, could have asked the participants for a fee, but then most likely not many students would have come.
Even after his retirement in 1958 and on into old age, Bernays continued to attend this especially lively seminar. A former student remembers standing at the blackboard expounding on a recently published article. He had hardly begun his presentation when Bernays asked the first question, which launched a debate with Professor Hans Läuchli, who stepped to the board and, chalk in hand, tried to solve the problem. Thereupon Professor Ernst Specker got up to present another version. Now Bernays, wanting to give more weight to his point of view, pressed forward. The conversation became more and more lively. The poor student, today a respected professor at the University of Lausanne, could barely, and only with great effort, finish his own presentation.
Bernays passed away on September 18, 1977. After his death, the tradition of logic was kept up by his former colleagues Läuchli and Specker. When Specker retired in 1987, his assistants and students urged him to continue the seminar, which he did for 15 more years. Several participants of the seminar are today professors at universities in different parts of the world.
