When the element of time was added to the concept of diagnosis, a diagnosis became more than just a description of a collection of symptoms: diagnosis now also defined by prognosis (course and outcome). An additional feature of the clinical method was that the characteristic symptoms that define syndromes should be described without any prior assumption of brain pathology (although such links would be made later as scientific knowledge progressed). Karl Kahlbaum made an appeal for the adoption of the clinical method in psychiatry in his 1874 book on catatonia. Without Kahlbaum and Hecker there would be no dementia praecox.