Jaspers' critique of essentialist theories of schizophrenia and the phenomenological response.

This contribution reviews the fin de siècle and immediately following efforts (Berze, Gross, Jung, Stransky, Weygandt, and others) to find a fundamental psychological disturbance (psychologische Grundstörung) underlying the symptoms of dementia praecox, later renamed schizophrenia by Bleuler (1908, 1911). In his General Psychopathology (1913), Jaspers brings order into the field by bringing to psychopathology a scientific basis coupled with phenomenological rigor. He was critical of theories that proposed an essence of schizophrenia, which is merely asserted verbally. This imperative is reiterated by other members of the Heidelberg School (Gruhle, Mayer-Gross, and K. Schneider). Gruhle (1929) contended that the primary symptoms of schizophrenia, indicating an underlying but still unknown neurobiological disease process, are independent from one another. They cannot be brought under a single, current theoretical model. That is, schizophrenia cannot be explained in terms of a 'catchword', which is only thought but not empirically studied. Sobered but also inspired by Jaspers' rigor, phenomenological psychiatrists (Binswanger, Blankenburg, Conrad, Ey, and others) proposed more tempered models, which could be studied empirically or tested scientifically. This historical progression may be viewed as a dialectical process: First, bold, merely verbal assertions without method were made, then Jaspers followed with a sobering critique, and finally, the existential-phenomenological clinicians/researchers responded by producing fine-grained, rigorous phenomenological models, tempered by humility and self-critique, which led to hypotheses that could be tested in current clinical neuroscience.