In Describing the concept ‘dementia praecox’, Kraepelin believed he had defined a unitary metabolic disorder. In widening the concept so that the newly named ‘schizophrenias’ implied the existence of a group of disorders, sharing certain pathological characteristics but having different causes, Bleuler provided an impetus for research into schizophrenia which was not limited to the identification of organic factors. Each in his own way gave rise to a school of thought whose approach to and understanding of schizophrenic illnesses contrasted sharply with the other. Kraepelin invited Ernst Rudin to Switzerland to help set up an intensive research study of the possible genetic basis of schizophrenia, whereas Bleuler’s approach was enthusiastically taken up by analysts and psychotherapists, convinced that the key to understanding the disorder would be found in a thorough exploration of intrapsychic and interpersonal conflicts.