Abstract

In his works on natural philosophy, Walter Burley designed a theory about one particular kind of opposition, namely contrariety. In this respect, one of his most peculiar tractates is the Tractatus primus. However, also in his Physics-commentary, in his Tractatus secundus and in the quaestio Utrum contraria adequata in virtute agant et patiantur ad invicem? one finds arguments revealing a dialectical approach to the problem of the specific identity and/or incompatibility of contrariously opposed qualities. Burley’s rea­­sonings compose an original attempt to use philosophical dialectic not only as a meth­od of disputation, but moreover primarily as a theory of the mediation of opposites. These arguments refer to the scope of natural philosophy, logic, ethics and medicine. An analysis of these arguments and of the criticisms of Thomas Wylton and Konrad of Megenberg reveals Burley’s dialectical approach to be an eminent historical contribution to the solution of fundamental questions within the realm of Aristotelian metaphysics