Against the background of the arrangements of ICD-11 and DSM-V, future approaches in order to diagnose schizophrenic psychoses are currently being discussed. In this context, the current concepts of schizophrenia are questioned because attempts at neurobiological validation and validation based on family and follow-up studies have not succeeded. Therefore, dimensional diagnostic models or a division into subtypes are suggested. Both of these proposals would imply a deconstruction of the current concept of schizophrenia. A historical review shows that the psychopathological roots of the current discussion can be traced back to Kurt Schneider's nominalistic concept of schizophrenia which is based upon the so-called first-rank symptoms. In contrast, the psychopathological foundation of dimensional concepts and a division into several subtypes date from contributions of Klaus Conrad and Karl Leonhard. A triaxial diagnostic system with the axes of syndromes, course types and aetiology could provide a bridge between the different approaches.