Abstract
The reorganization of psychiatric knowledge at the turn of the twentieth century derived from Emil Kraepelin’s clinical classification of psychoses. Surprisingly, within just few years, Kraepelin’s simple dichotomy between dementia praecox (schizophrenias) and manic-depressive psychosis (bipolar disorders) succeeded in giving psychiatry a new framework that is still used until the present day. Unexpectedly, Kraepelin’s simple clinical scheme based on the dichotomy replaced the significantly more differentiated nosography that dominated psychiatric research in the last three decades of the nineteenth century (Janzarik in Themen und Tendenzen der deutschsprachigen Psychiatrie. Springer, Berlin, 1974 ). Moreover, although all the components of the future development were already available shortly after 1868, the real course, which led to Kraepelin’s dichotomy, was unpredictable then. This paper explores the ways in which the unpredictability of psychiatric knowledge and the postulate of a rationality underlying psychopathological phenomena interacted in the debates regarding the classification of psychoses. It examines the “natural antagonism” between the practical aspirations of an increasingly specialized medical nosology and unitary conceptions, which, in a psychopathological countermovement, emphasized that no somatic criteria can be specified for the majority of psychic abnormalities and that all nosological distinctions are not binding (Janzarik 1974, 20). In this context, this paper investigates the revival of unitary theories of psychosis in postwar German psychiatry and seeks to understand why the forms of thinking that dominated nineteenth-century psychiatry have proved to be very lasting. Furthermore, this paper emphasizes the perspectivity underlying psychiatric research on psychoses and explores the ways in which writing the history of the schizophrenia concept involves inevitably writing the history of the entire psychiatry.