Historians continue to disagree over whether he aimed to replace or enhance the concept of dementia praecox put forward by the German psychiatrist Emil Kraepelin in 1893. For Kraepelin, dementia praecox-an untimely loss of mental function-was one of a group of degenerative conditions characterised by “the unusually rapid development of a lasting state of psychic weakness”. Psychoanalysts interpreted it as a failure of ego development; followers of the radical Scottish psychiatrist R D Laing pointed to familial tensions and the “schizophrenogenic mother”; and the British psychiatrist Edward Hare wondered whether the steady increase in records of schizophrenic behaviour since the early 19th century indicated a viral origin.