Abstract

The aim of this paper is to analyse and to discuss the philosophical reflexions on Geometry due to Blaise Pascal, Antoine Arnauld and Pierre Nicole. All of them were linked to the Jansenism, religious movement whose centre was at the Port Royal abbey. Our theses is that their philosophical thoughts on Geometry as well as their criticism of Euclid’s Elements were rooted not only in the works of the geometers and Element’s translators and commentators of the sixteenth century but also on their particular conceptions about human knowledge and soul. Our text is divided into five parts. In the first part we examine the place of Geometry in the culture of the seventeenth century. After that, in the second part, we discuss the standard criticism directed against Euclid’s Elements. In the third part we analyse three works of Pascal: The spirit of geometry, The art of persuasion and some fragments that have survived of a text entitled Introduction of Geometry. In the fourth part we discuss the critical remarks of the Logic of Port Royal on the geometrical works, especially on the Elements. The fifth part of our work is devoted to Arnauld’s reconstruction of plane elementary Geometry in his New Elements of Geometry. The conclusions are set forth in the sixth part.