Although Margaret Cavendish, Duchess of Newcastle (1623–1673), did not belong to the scientific community which after 1660 formed itself around the Royal Society, several of the philosophical issues discussed there are reflected in her writings. Lengthy reflections on language and style which run through her philosophical works provide evidence that the linguistic and rhetorical debates of the early Royal Society also left their mark. The isolation which Cavendish faced as a woman writer obliged her to discuss problems of terminology and style even more intensively, thereby adhering to the rhetorical principle of perspicuity which Thomas Sprat demanded in his proposal for a scientific plain style. The influence of the New Science on Cavendish’s work becomes obvious when her later writings are compared to her earlier ones where traces of a courtly and more elitist understanding of style can still be found. In this paper the development of Cavendish’s stylistic attitudes is traced in several of her works, including her Utopian narrative The Blazing World (1666).