Table 3.

Glossary of Kraepelin's main nosological terms

Nominalist terms Disorder (Krankheitsform): The basic unit of psychiatric nosology. Clinical picture (Zustandsbild): The cross‐sectional description of psychopathology. Disease concept (Krankheitsbegriff): Initially a nominalist definition of a psychiatric disorder. When final, it links causes with all clinical phenomena and explains course and outcome. Disease process (Krankheitsvorgang): The evolution of clinical pictures over time. Only longitudinal observations can reveal this active process.

Realist terms Disease picture which corresponds to nature (der Natur entsprechendes Krankheitsbild): A nosological entity that represents nature. Natural disease process (natürlicher Krankheitsvorgang): A process occurring in nature, giving rise to clinical phenomena.

Kraepelin blends nominalist with realist views. The nominalist terms are descriptive and preliminary: they allow us to assign a diagnostic label. The realist terms capture what nature has revealed to us. For Kraepelin, psychiatric nosology progresses, through conjecture and refutation, from constructivism to realism. Kraepelin was not always consistent in the use of his terms 48 .