Imaginable Impossibilities and Thought Experiments

"The ontological foundation of possibilities in 12th century logic"

Intersections conference

The conference Intersections of theology, language and cognition in medieval tradition and beyond, which was supposed to take place at the University of Bologna on May 12th and 13th, has moved online.

The paper I presented to this conference was about the ontology and metaphysics of possibilities as was conceived by several logicians in the 11th and 12th century – and on which influence this ontology had on later developments of medieval modalities.

As is known, early medieval reflections on modalities are deeply indebted to the modal theories developed by Aristotle in De Interpretatione, to which scholars were acquainted through the mediation of Boethius’ translation and commentaries. 

Eleventh- and early twelfth-century authors inherited from Aristotle and Boethius a specific syntactic structure, one that they used to construct propositions about possibility, impossibility, necessity and contingency, as well as a number of rules they applied to describe the logical behavior of such propositions.

From the same sources, they also inherited a number of philosophical issues related to modalities, such as the discussion on what should be comprised within the realm of possibility (in particular, whether this should include possibilities that are never actualized), and the problems concerning future contingents and the existence of free agency.

Even though these traditional modal views were considerably enriched in the early Middle Ages with a more sophisticated syntax for modal propositions and a more expressive logic, the general framework in which modal language was analyzed remained essentially Aristotelian in spirit.

However, the theory of modalities reported by Aristotle and Boethius were also loaded with certain metaphysical assumptions that some early medieval authors felt uncomfortable carrying along. This metaphysical background was mostly connected to the Aristotelian interpretation of possibilities as ontologically funded in the potencies or potentialities of things, that is in the powers, tendencies or capacities that certain substances have of being otherwise than they actually are.

I argue that during the 11th and especially the 12th century this modal paradigm changes considerably.

To see how, you may find my video-paper to the conference here. A written article based on this paper is currently under review.

My thanks to Monika Michalowska, Riccardo Fedriga and Costantino Marmo for organizing this online conference.