« The Mathematical Theses Defended at collège de Clermont (1637-1682) : How to Guard a Fortress in Times of War », en collab. avec D. Collacciani

Early modern theses that were defended in colleges and universities have recently attracted historical attention. They were first studied by historians of art and of the book : the illustrations that some theses included allowed scholars to reconstruct their material and social production as well as the ceremonies associated with their public defense. More recently, among other documents, their doctrinal content has been of interest for intellectual historians studying the transition from the so-called “philosophy of the Schools” to the modern philosophy, especially, but not only, in Jesuit colleges. An impressive book has thus been devoted to theses in logic, natural philosophy, metaphysics, ethics, and politics that were defended between 1555 and 1648 at the University of Dilingen, the first Jesuit University north of the Alps. Yet theses in mathematics defended in Jesuit colleges remain understudied. Often only a few printed mathematics theses remain—we do not know if the other mathematics theses were never printed or they were printed but then lost.
This chapter studies mathematics theses defended during a period of fifty years at the collège de Clermont in Paris, the most important French Jesuit college. It begins at the end of the thirties, around the time when Descartes’s Discourse on method and Essays (1637) appeared ; this moment also corresponds to when these theses began to be defended or at least to be published. The chapter ends in 1682, when the collège de Clermont, having received the patronage of Louis XIV, became Louis-Le-Grand. Our first objective, which belongs to social history, is to capture some of the teaching practices of the early modern period. Our second objective, which falls within intellectual history, is to explain how the ancient and the new doctrines interacted, more specifically how French Jesuits reacted to Descartes and to other novatores. To reach these two aims without writing an excessively long paper, we will focus on optics and leave aside other disciplines tackled in these theses, including military architecture, mechanics, and cosmology.
We begin with a general presentation of the corpus, which is exceptional insofar as there is almost one thesis per year, so that one can identify structural features common to all of the theses, but also variations from professor to professor and changes over time (II). Then, we focus on the optics theses that were defended during the long period in which Pierre Bourdin was the professor of mathematics at collège de Clermont (III). The brief time when Ignace-Gaston Pardies held the same chair some twenty years later on gives us the occasion to discuss an optics that fully incorporated the lessons of the novatores, even if it claims to respect the doctrine of the Ancients (IV).