Karl Theodor Jaspers (, ; 23 February 1883 – 26 February 1969) was a German-Swiss psychiatrist and philosopher who had a strong influence on modern theology, psychiatry, and philosophy. After being trained in and practicing psychiatry, Jaspers turned to philosophical inquiry and attempted to discover an innovative philosophical system. He was often viewed as a major exponent of existentialism in Germany, though he did not accept the label. Biography Jaspers was born in Oldenburg in 1883 to a mother from a local farming community, and a jurist father. He showed an early interest in philosophy, but his father's experience with the legal system undoubtedly influenced his decision to study law at the University of Heidelberg. Jaspers first studied law in Heidelberg and later in Munich for three semesters. It soon became clear that Jaspers did not particularly enjoy law, and he switched to studying medicine in 1902 with a thesis about criminology. In 1910 he married Gertrud Mayer (1879–1974), the sister of his close friends Gustav Mayer and Ernst Mayer. Jaspers earned his medical doctorate from the University of Heidelberg medical school in 1908 and began work at a psychiatric hospital in Heidelberg under Franz Nissl, successor of Emil Kraepelin and Karl Bonhoeffer, and Karl Wilmans. Jaspers became dissatisfied with the way the medical community of the time approached the study of mental illness and gave himself the task of improving the psychiatric approach. In 1913 Jaspers habilitated at the philosophical faculty of the Heidelberg University and gained there in 1914 a post as a psychology teacher. The post later became a permanent philosophical one, and Jaspers never returned to clinical practice. During this time Jaspers was a close friend of the Weber family (Max Weber also having held a professorship at Heidelberg). In 1921, at the age of 38, Jaspers turned from psychology to philosophy, expanding on themes he had developed in his psychiatric works. He became a philosopher, in Germany and Europe. After the Nazi seizure of power in 1933, Jaspers was considered to have a "Jewish taint" (jüdische Versippung, in the jargon of the time) due to his Jewish wife, and was forced to retire from teaching in 1937. In 1938 he fell under a publication ban as well. Many of his long-time friends stood by him, however, and he was able to continue his studies and research without being totally isolated. But he and his wife