[Aphoria of psychopathology: attempt at a meta-analysis]

A psychiatric differential diagnosis is first of all an eidetic typology, a taxonomy of specific types. Psychopathological effort as yet did not fully succeed to unveil the respective specificity. Therefore we may well speak of a certain aporia. By the example of the group of schizophrenias the question, inherent in the notion of aporia, is followed, if it is created by the subject itself or by the methodological approach. As a result we can show various methodical problems. The effect of these methodical problems seems to be very proper to melt away the differentia specifica, if existent and so could be valued as arguments for the possibility of a methodical aporia. Given such an aporia, another reading of the findings concerning course and outcome of schizophrenia may result. Possible perspectives to further methodical developments are suggested.