The name of Karl Jaspers represents a particular constellation of thought which characterized the cultural life in Germany at the beginning of the twentieth century. Philosophy, humanities, social sciences, and medicine conjoined to enter into a dialogue. In this intellectual environment, Karl Jaspers first studied medicine from 1906 to 1909, then worked as a psychiatrist at the Psychiatric Clinic of Heidelberg, headed by Karl Wilmanns, until he took a chair for philosophical psychology in 1914. As early as 1913, at that time being a 29-year-old clinical assistant, he published his “General Psychopathology”, a pioneering achievement in overcoming the disciplinary boundaries. Although moving more towards philosophy later on, Jaspers attempted to combine psychiatry, medicine, philosophy, and the humanities throughout his life. Thus, he also supplemented his approach to psychopathology by adding extensive parts of his existential philosophy to the original work, in particular in the 4th edition of 1942.

The central motive that connects Jaspers’ manifold works is the idea of human existence. He conceives it as the foundation of all scientific theories which are based on the human being without being able to grasp it completely. Scientific investigation should therefore be complemented by a permanent reflection on prescientific human experience. This idea remains valid independently of Jaspers’ existential philosophical terminology. It may be reformulated as follows: Science is based on the human life-world, ie, on subjective and intersubjective experience. It starts from this experience and gains its final destination from it. Only in constant dialogue with the life-world is science able to attain relevant knowledge without decoupling itself from human self-understanding. This is true in particular for the sciences, whose subject matter is the suffering human being, ie, medicine in general, and psychopathology and psychiatry in particular. When Jaspers published his “General Psychopathology”, the field of psychiatry was characterized by a rapid expansion of the neurosciences, above all neuroanatomy and neurophysiology. Jaspers was aware of the risk that psychiatry could lose its anchoring in the patients’ subjective experience by indulging in what he called “brain mythologies”. In this situation, his main concern was to bring order into the field by meticulous descriptions of subjective phenomena, concise definitions of concepts, and systematic classifications of types of disorders, thus endowing psychiatry with a valid and reliable method.