Kurt Godel could be paranoid at times. And, perhaps he had good reason to be.
Born in what was then Austria-Hungary in 1906, he became a citizen of Czechoslovakia at the age of 12 when the Austro-Hungarian empire broke up. After surviving a bout of rheumatic fever at the age of six, Godel was left with a lifelong fear that his heart had been permanently damaged. By the age of eighteen, he moved to Vienna to study theoretical physics. After being inspired by the work of David Hilbert and Wilhelm Ackerman, Godel changed his major to mathematics and logic and went on to receive his doctorate at the age of thirty.
It was his doctoral dissertation on first-order predicate calculus (a.k.a. Godel's completeness theorem) that launched Godel's reputation as a logician. Establishing a correspondence between semantic truth and syntactic probability in first-order logic, Godel soon followed with his proof of his incompleteness theorems demonstrating the inherent limitations of most mathematical systems. In a two-page paper which he published in 1932, Kurt Godel also refuted the finite aspects of intuitionist logic and first demonstrated what would be later known as fuzzy logics.
Despite his rising fame as part of the "Vienna Circle" of philosophers at the University of Vienna, Kurt Godel's life was rapidly being affected by the changing political situation in Austria. Since he always considered himself to be an Austrian at heart, Godel became an Austrian citizen at the age of 23. Unfortunately, this automatically made him a German citizen following the Anschluss in 1938 and it was the rising Nazi influence that would mark the rest of his life. Among Viennese mathematicians, there was a general purging of "un-german" philosophies (especially Jewish academicians) and many members of the Vienna Circle fled to the U.S.A. After Godel's mentor, Moritz Schlick, was assassinated by a pro-Nazi student on June 22, 1936, there was considerable anti-Jewish propaganda used to justify the killing (despite the fact that Schlick wasn't Jewish). Schlick's murder and the resulting media frenzy sent Godel into an emotional tailspin and he experienced what biographers would later call a "severe nervous crisis". He spent several months in a sanatorium and first developed the paranoid symptoms that would haunt him from then on (including a fear of being poisoned).
Remaining in Austria proved to be increasingly dangerous for Godel. Not only did have difficulty securing a university position due to his past association with Jewish members of the Vienna Circle, but he was also eligible for the military draft. By 1939, World War II had begun and Godel had enough. He and his wife Adele quietly traveled to the United States where he took a position with the Institute for Advanced Study in Princeton. Already well-known in Princeton due to his many guest lectures there, Godel quickly established himself and was able to resume his mathematical work. He and Albert Einstein became fast friends and Einstein himself would later say that "walking home with Godel" was one of his daily highlights at the Institute.
Unfortunately, Godel's experiences with the Nazis had marked him and this paranoia never really subsided. Although he was able to continue with his mathematics work, the fear that the U.S. might descend into a dictatorship remained with him. Even during his U.S. citizenship test, he confided to Einstein and Oskar Morgenstern (who served as his citizenship sponsors and accompanied him to the examination) that he had found an inconsistency in the U.S. constitution that might allow for a dictatorship. Although Einstein and Morgenstern cautioned him not to mention this during the swearing-in ceremony, everything nearly unravelled when the presiding judge happened to comment on Godel's experience with dictatorship and commented that an "evil dictatorship" of that nature wasn't possible in America. That was too much for Godel who promptly burst out with his explanation of how a dictatorship would be possible under the constitution. It took the combined efforts of Einstein, Morgenstern, and the judge to control Godel's quirky behaviour long enough to complete what would have been an otherwise routine formality.
Throughout Godel's lifetime, it was his wife Adele who acted as his primary support. From the beginning of their marriage in 1938, Adele was Kurt Godel's fiercest defender. Once, when confronted by Nazi brownshirts, Adele literally fought them off with her umbrella. When Godel developed a fear of being poisoned, Adele made it a point to prepare all his food herself and also acted as his foodtaster. After their move to Princeton, the Godels eventually purchased a modest house in an immigrant neighbourhood and far from where his colleagues lived (Adele preferred to live near other German-speaking neighbours). While Adele occasionally returned to Europe to visit family after the war, Kurt Godel never left the U.S.A. again and even turned down the offer of a visiting professorship in Austria in 1966.
In his later years, Godel became even more peculiar. He continued his work and but he moved into new, and often surprising directions, including a growing interest in metaphysics and the occult. As his health deteriorated in the 1950s, he made various self-diagnoses and the paranoia worsened. His personal physician, Dr. Ramona later commented that, "he was actually a very difficult patient. Once I was called to his house because he was spitting blood. I diagnosed bleeding ulcer, but he refused to go to the hospital, and it was only Einstein's art of persuasion that changed his mind". When Albert Einstein died in 1955, Godel lost his closest friend at Princeton and he became more isolated than ever.
Kurt Godel's involvement with Princeton continued and he was eventually awarded a National Science Medal in 1974 and became an emeritus professor in 1976. Still, he became completely dependent on Adele who represented his only family (the Godels never had children and he rarely saw his brother who lived in Austria). His fear of being poisoned grew steadily worse and he eventually began preparing his own food to ensure it was cooked properly. He also became increasingly guilty and anxious over the feeling that he had failed to accomplish what he considered to be expected of him at the Institute. Despite consulting with psychiatrist Richard Huelsenbeck, there was little improvement and even Adele grew exasperated with her husband's odd behaviour.
The final crisis came in 1977 when Adele was hospitalized for six months following major surgery. Her long illness and hospitalization made her unable to care for her husband as usual. In Adele's absence, Kurt Godel refused to eat any food that she had not prepared and began to waste away from malnutrition. On December 29, 1977, Hassler Whitney, one of Godel's Institute colleagues, called Dr. Ramona and said that Godel was severely dehydrated and in poor condition. Whitney then brought Godel to the Princeton Hospital emergency room where he was admitted. Even in hospital, Godel refused to eat and continued to waste away. By the time of his death on January 14, 1978, Kurt Godel was severely emaciated and the cause of death listed on the death certificate was ""malnutrition and inanition caused by personality disturbance". According to Dr. Ramona, "He had refused all food. He had never eaten very much, but his final weight was only around 60 pounds. He died in the fetal position." He is buried in a Princeton cemetery with his wife Adele (who died in 1981).
It took two years to catalogue the sixty boxes of personal papers and documents that Kurt Godel left behind. Now part of Princeton's permanent collection, many of his papers and personal correspondence have been published in five volumes in addition to the numerous commentaries and biographies that have been written about him. The Kurt Godel Society was founded in 1987 to promote research on logic, philosophy, and the history of mathematics.
All in all, it is a fitting legacy for such a complex individual.