The Christianization of Pyrrhonism results from the encounter of a Renaissance tradition of Sceptical Fideism with a revival of Augustinianism - epitomized in the Jansenist movement - during the seventeenth century. This section is about this context. I begin by indicating the basic theological views that opposed Jansenists and Jesuits, then I focus on the Jansenist perception of theological heresies implicated by their contemporaries' interest in Greek-Roman philosophies.¹