Psychopathological, nosological, and prognostic aspects of basic stages and basic symptoms, in particular consideration of formal thought disorders, are outlined. In view of the far-reaching overlap of the psychopathological pictures of the pre- und postpsychotic basic stages a Bonn Scale for the Assessment of Basic Symptoms (BSABS) including all types of basic stages was constructed. Subjective cognitive thought disorders were recorded from 69% of the patients in pure defective states, from 78% in postpsychotic reversible basic stages and from 67% in prodromes. In contrast to incoherence of thoughts, including the symptoms of the endogenomorphic-schizophrenic axial syndrome (Berner), these thought disorders are registered only on the basis of the reports of the patients and not through observation by the investigator. The difference between subjective and objective thought disorders is presumably only conditioned primarily by differences in the degree and secondarily by the psychopathological quality of the disorders. If the criteria concerning formal thought disorders and affective blunting of the schizophrenic axial syndrome or of SANS (Andreasen) are fulfilled, as a rule the patient loses the ability of perceiving, communicating, and coping with the disorders, and at the same time there is a break from an only quantitative to a qualitative abnormal phenomenon. The presence or absence of subjective or objective formal thought disorders in the beginning of the disease had no significant influence on the long-term outcome in the main sample of the Bonn study. Proceeding from the initial psychopathological syndromes 54% of the female hebephrenics with the most unfavorable long-term prognosis showed incoherence of thoughts in the first 2 years of the illness; in contrast, incoherence was seen in only 16% of the male hebephrenics for whom the long-term outcome did not differ from that of the whole sample. This and other data of the Bonn schizophrenia study seem to argue in favor of the assumption that typical incoherence of thoughts might be valuated as a criterion of unfavorable prognosis only when the phenomenon appears within the context of a hebephrenic initial syndrome in the beginning of the schizophrenic disease.