Probably few psychiatrists would spontaneously associate Emil Kraepelin's name with philosophy. Nevertheless, I think it is necessary to look at this relationship for the following reasons: During recent years, several authors have described a crisis in psychiatry, particularly in psychiatric diagnosis. It is not purely coincidental that in such a "critical" era, many concepts and ideas are "re-discovered" which previously have been regarded as of merely historical interest. This is especially true of Emil Kraepelin's psychiatry. The influence of what is often called the "neo-Kraepelinian movement" is well-known, an influence which manifests itself, for example, in the operationalized diagnostic criteria of DSM-III-R, and which proves the profound relevance of Kraepelinian ideas for present-day psychiatry (Blashfield 1984). Given this situation, it seems appropriate to critically reevaluate Kraepelin's nosological positions as they changed over time (which cannot be further discussed here), and—our present topic—to highlight the philosophical implications of this nosology, although—as will be shown—they often are quite well hidden.¹