In this paper the disciplines medicine and natural science are interpreted as discourse communities, and it is assumed that discourse communities are characterized by their writing styles. The difference between the writing styles of the two discourse communities is demonstrated by a multidimensional analysis of five medical and five science texts of the 17th century. Robert Boyle (1627-1691) is introduced as a member of the medical and of the science discourse community. A corpus of five of his medical and five of his science texts is analyzed to test the hypotheses that his medical and his science writing styles were as different from each other as the writing styles of the authors of the other 17th century medical and science texts, and that Boyle followed the discourse practices of his contemporaries. Both hypotheses are refuted, and Boyle’s deviating writing styles are explained as manifestations of his authorial identity. The appreciation of Boyle’s achievements by the medical and science discourse communities of the 18th century is taken as the motivation for the hypothesis that his writing styles, too, were admired and imitated. This hypothesis is tested through a diachronic analysis of 17th century medical and science texts, Boyle’s medical and science texts, and 18th century medical and science texts. A comparison of their linguistic profiles weakly support the hypothesis in the case of Boyle’s science writing style and strongly in the case of his medical writing style. As a conclusion it is suggested that future research should treat science and medicine as distinct disciplines already in the 17th century and that linguists should pay more attention to Boyle’s medical texts.