The article proposes a model for linguistic analysis of scientific thought-styles, combining quantitative and qualitative analyses in the variationist frame and focusing on writings of the scholastic period. The first part of the article considers factors that led to the vernacularisation of scientific writings in fifteenth-century England and the sources, underlying traditions, and audiences of these writings. The empirical part focuses on two features typical of scholasticism: references to authorities and the use of prescriptive phrases. The results show statistical differences between varieties of writing. A close semantic analysis reveals a pattern which is related to the underlying layers of traditon and to the sociohistorical background of the texts. The material comes from a computer-readable Corpus of Early English Medical Writing 1375-1750, which the authors are compiling at the University of Helsinki.