Integration and Transformation in Late Medieval Natural Philosophy: Jacques Legrand's Aristotelian Compendium utriusque philosophie

• Applicant: Dr. Daniel Antonio Di Liscia
• Subject Area: History of Philosophy
• Term: from 2015 to 2022
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 282682744

This research project deals with the application of logical- mathematical methods and concepts to late medieval metaphysics. It focuses on the exploration of the problem of the perfection of species (perfectio specierum), which emerged during the second half of the fourteenth century and concentrates on the following question as a central theme: If all beings belong to one genus, how can there be a systematic, hierarchical golden chain of all beings, a catena aurea entium, from the lowest material creature all the way up to the Supreme Being? This question (and, of course, a wide range of other particular difficulties) bears on the philosophy and theology of the late Middle Ages and extends to an area of application for new techniques in logic and the philosophy of language, especially for the calculationes that originated in Oxford and rapidly spread to several other universities across Europe (Leibniz still speaks enthusiastically of them). How can the perfectio of different individuals within a species be understood quantitatively? Can a decrease or increase of this quality take place in the course of time, and if so, how can we describe their amplitude (latitudo) between their possible maxima and minima? While the approach of the calculatores to applying new analytical languages spread, a new approach for the treatment of these problems arose, especially in the work of Nicole Oresme. Oresme and a few followers preferred geometry, from which they promised greater clarity in representing those magnitudes. In fact, Oresme tried to develop a new independent discipline consisting in the study of the representation of qualities and movements (configurationes doctrine). In addition, a further aspect grew in significance, namely that geometry is by nature better able to deal with steady, continuous quantities. This resulted in an innovative way of dealing with the issue of perfection of species, which was clearly discussed in the hitherto little-studied Tractatus de perfectione specierum by Jacobus de Neapolis. Rather than a representation by means of arithmetic, Jacobus decided on a continuous representation of all beings using geometric structures. This text, of which only three manuscripts have been reported thus far, is central to the present project and therefore should be edited from eleven manuscripts, translated and commented. Nevertheless, Jacobus treatise is not an isolated case. Numerous evidence suggests that in the generation immediately following the perfection of species witnessed a general shift from theology to metaphysics. In this regard, the project will focus on four main sources that prove the survival of this problem in the context of the metaphysics of the late Middle Ages (N. T. de Amsterdam, P. Venetus et alii).

• DFG Programme: Research Grants