<jats:p xml:lang="en"> The meaning of genius in public discourses on eighteenth-century sciences was exceptionally ambiguous and conflicted. These meanings can be explored and their uses documented in the case of Bernard de Fontenelle’s éloges , pronounced as secretary of the Académie Royale des Sciences during the early eighteenth century. His remarkable éloge of Isaac Newton, delivered in November 1727, skilfully used the various senses of the notion of genius both to explain the grandeur of the Englishman’s achievements and to offer a critique of fundamental aspects of Newtonian sciences and culture. </jats:p>