The fundamental differences between the syndromes united under the term of schizophrenia are demonstrated. Attempts to reduce these syndromes to a common denominator of a nosological unit bearing the same designation have failed. Important arguments are advanced against the identification, widespread in practice, of the terms "paranoid" and "schizophrenic". It is pointed out that these two terms are incompatible to some extent. There is a fundamental difference between the nature of paranoia and the symptoms characteristic of schizophrenia (Dementia praecox). Paranoia is far more dependent on the personality than on the pathological process. A division into three aspects - schizophrenia, paranoid psychoses and MDP instead of the dichotomy schizophrenia/MDP, is proposed for a better theoretical and practical understanding in the field of endogeny. Further semantic arguments are advanced against the term "schizophrenia" indicating its iatrogenic effect.