Logical Geometry and Aristotelian Diagrams (06_2022)

Logical Geometry and Aristotelian Diagrams: Interview with Lorenz Demey

by Guido Alt

Aristotelian diagrams are familiar to most students of logic, and to anyone who has studied history of logic in particular – from classical squares of opposition to more complex varieties such as octagons of opposition, diagrams have been used to study logical relations from antiquity through the Middle Ages and beyond. While they are an important part of the history of logic, do they also have contemporary relevance? Lorenz Demey (Leuven) argues that they do. In this interview, he introduces us to his studies on logical geometry – which comprises the study of Aristotelian diagrams – and argues that Aristotelian diagrams, in their variety of applications, merit consideration as independent objects of study from logical, philosophical and historical perspectives. We spoke about Lorenz’s trajectory leading up to his ERC project on logical geometry and Aristotelian diagrams, what they are and their contemporary relevance, the use of formal and mathematical tools in the history of logic, and much more.

About Lorenz Demey

Lorenz Demey is a research professor at KU Leuven, where he works on philosophical logic. Lorenz has been doing research on logical geometry and Aristotelian diagrams for several years, in close collaboration with colleagues working on logic, formal semantics, computer science, and history of logic. Among other things, he has worked on building a database with empirical data on Aristotelian diagrams entitled Leonardi. His research on this has culminated in the ERC project he will lead coming September this year, entitled STARTDIALOG: Towards a Systematic Theory of Aristotelian Diagrams in Logical Geometry. The project aims to give a unified and coherent account of Aristotelian diagrams from a logical, philosophical and historical perspective.