The article presents a socio-semantic study of evaluative expressions in medical scientific articles from six periods from the eighteenth, nineteenth and twentieth centuries. Evaluations relating to the presentations of the medical case, the scientist’s own work and the work of other scientists were studied. The results of the analyses point to a gradual change in the directness of the evaluations; where the author earlier evaluated through his own voice, the modern author chooses to evaluate indirectly through facts and others’ voices. The evaluations were also found to gradually be less strong and more embedded in hedgings of various kinds. The changes in evaluative strength and style reveal the varied positions of the scientists and their scientific community as to the medical knowledge, the stage of the medical community and the role of the medical scientists in society.