Karl Theodor Jaspers (, German: [kaʁl ˈjaspɐs] ; 23 February 1883 – 26 February 1969) was a German-Swiss psychiatrist and philosopher who had a strong influence on modern theology, psychiatry, and philosophy. His 1913 work General Psychopathology influenced many later diagnostic criteria, and argued for a distinction between "primary" and "secondary" delusions.
After being trained in and practising 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.
