The procedure of meticulous description of the signs and symptoms of disease with ascription to localization applied was decisive to Leonhard's phenomenological approach to the classification of endogenous psychoses.

Karl Leonhard is to be honored by the Department of Psychiatry at the University of Erlangen, the starting point and character-moulder of his clinical and academic career.

Relevant Archive material as well as primary and secondary literature will be assessed.

In 1930, in his contribution to the commemorative volume on Gustav Specht (1860-1940), the first Head of Psychiatry in Erlangen, Karl Leonhard presented a very detailed description of the hallucinatory pattern of a postencephalitic patient. Leonhard practised in this the differentiation between organic and endogenous psychoses. The Psychiatric and Neurological Hospital at the University of Erlangen being an adnexe to the Erlanger asylum for the mentally ill, Leonhard was also able to become acquainted with acute and chronic stages of schizophrenia. This can be viewed as the decisive impulse for his later differentiated classification of types of schizophrenia. Leonhard took from Gustav Specht the aspect of bipolarity, which is decisive for his cycloid psychoses. The prominent importance of anxiety, which Specht promulgated, was later used by Leonhard in the description of anxiety-happiness psychosis. Leonhard's unsuccessful efforts to retain the Erlanger Chair in 1955 can be viewed as his first difficulty in West-East- and East-West German tensions.

Appropriation of Leonard's diagnostics can contribute to differentiated pharmacotherapeutic strategies in cycloid psychoses.