The history of biostatistics could be viewed as an ongoing dialectic between continuity and change. Although statistical methods are used in current clinical studies, there is still ambivalence towards its application when medical practitioners treat individual patients. This article illustrates this dialectic by highlighting selected historical episodes and methodological innovations – such as debates about inoculation and blood - letting, as well as how randomisation was introduced into clinical trial design. These historical episodes are a catalyst to consider assistance of non-practitioners of medicine such as statisticians and medical writers.