Theorizing on Dispute. The teaching of Dialect at Louvain University ( 1425-1645)

This dissertation contains a study of theories of topical logic (or dialectic). Topical logic goes back to Aristotle (384-322 BC), who initiated the study of logic in the West, and it formed an integral part of logic until deep into the seventeenth century. Our knowledge of how topical logic developed through the centuries is still very fragmentary, however. This dissertation aims to shed new light on the evolution of the discipline from Aristotle to the early sixteenth century. It consists of two parts. Part I gives a reconstruction of the two most important ancient systems that have come down to us: the system of Aristotle (Chapter 2) and the system of Boethius (c. 475-c. 525; Chapter 3). Part I ends with a synoptic overview of the discourse that developed after the rediscovery of the so-called logica nova during the late twelfth century (Chapter 4). The originality of Part I mainly lies with the fact that the theories under consideration are approached not historically, as is the case in most studies of topical logic, but rationally, and are thus interpreted by using methods from present-day systematic (philosophical and mathematical) logic – modal logic in specific – and formal philosophy more broadly, like judgment aggregation theory and formal dialectic. Part II contains a study of theories that were developed in the context of the so-called Wegestreit between traditionalism (via antiqua) and modernism (via moderna) during the fifteenth and early sixteenth centuries. There is widespread agreement among scholars that the Wegestreit essentially concerned ontological issues – and the theory of universals in the first place –, yet radiated to several branches of logic, ranging from the theory of predication to modal logic. Whether and how the Wegestreit shaped theories of topical logic, however, has hardly been studied. This is the hiatus that Part II addresses. For reasons of feasibility, Part II focuses on one specific corpus of primary sources, viz. treatises on topical logic that were written at the University of Louvain (founded 1425) during the period under consideration. The theories contained in these treatises are approached rationally, and they are interpreted against the backdrop of what in this dissertation is called the “Traditionalist Thesis” (TT). TT holds that the logical discourse in Louvain during the Wegestreit was almost exclusively traditionalist in nature, an idea that finds wide support among both university historians and historians of philosophy. TT is introduced in Chapter 1, and it is the guiding thread throughout this dissertation. Part II argues that the bifurcation of traditionalism versus modernism is clearly discernible in the late-medieval discourse on topical logic, and, more specifically, that the study of the Louvain sources contradicts TT. Some Louvain treatises contain unmistakable traces of modernist topical logic.