Talk: Daniel Di Liscia (MCMP)

Title:

Quantifying Infinity in the Late Middle Ages

Abstract:

Aristotelian natural philosophy always carried with it an anti- or at least an a-mathematical reputation. I will challenge this claim by presenting a very particular approach used by the calculators—a philosophical stream that emerged in the third decade of the fourteenth century—when dealing with the infinite, arguably the most complex notion in late medieval philosophy and science. At the core of my presentation will be an analysis of “infinite series” in the works of Richard Swineshead, and, above all, in those of Nicole Oresme, who, in his treatise On the configurations of Qualities and Motions (De configurationibus qualitatum et motuum), refers to a “more subtle and difficult” earlier demonstration by himself. I aim to explain some problems related to this text itself and pay special attention to its singular approach to demonstration, which I like to call “pre-recursive”.
For adequate contextualization, I shall integrate into my discussion some idiosyncratic commentaries on Aristotle, especially by Jean Buridan and Lawrence Lindores, and briefly present the reception of this remarkable proof, known as conclusio mirabilis, in Italy and within the circle of John Mair in Paris. By offering an analysis of this text using my critical edition of it, I intend to open the discussion toward a different interpretation of late Aristotelian natural philosophy, according to which a quantitative understanding of some of its basic notions was not only possible but, in fact, quite common.