[Conceptual vs. indexical symptomatologies of schizophrenia]

We discussed the difference of conceptual and indexical symptomatologies of schizophrenia through critics upon the theory of Eugen Bleuler, the diagnostic schema of Kurt Schneider and several recent theories of negative symptoms of schizophrenia. The notion of the group of schizophrenia of Bleuler, which is a descriptive expression of the phenomenon originally grasped in the inter-human relationships, is of conceptual value but confusing when used indexically for the definition of the illness. In the diagnostic concept of Schizophrenia by Schneider, although he explicitly sought for indexical value without any conceptual prejudice, Jaspers' notion of the psychoses defined by understandability is implicitly included. Schizophrenia is regarded as a form of psychosis which is, following Jaspers, a synonym of madness. Since then, the value of Schneider's 1st rank symptoms has been generally acknowledged and they have contributed to the development of operational diagnostic criteria of schizophrenia. However, the general neglect of unproductive symptoms has caused a new stream of operational symptomatology, namely negative symptoms. This stream includes not only biological researches but also ideological investigations of the essential disturbance of schizophrenia, which have been totally ignored in the operational symptomatology. The discussion of negative symptoms of schizophrenia is complexed because it contains both indexical and conceptual symptomatologies: this very complexity also contains the possibility of the integration of these two apparently distant methods.