We all know that coughing is only a symptom of a disease; it is not a clinical entity. That is to say, one may cough because he has tuberculosis, or perhaps an ordinary so-called cold. And so, too, with mania. Among the mentally ill there is no form of psychosis that may not show a period of that so-called mania. It is just a symptom. And so, as you see, symptoms were taken for diseases and there were a great many misunderstandings.