A conference on the Calculators and their ethical theories

My paper “Thinking and believing the impossible. Medieval reflections on opinabiles and inopinabiles impossibilities” will be presented at the international online conference “The Oxford Calculators and their milieu on Ethics” (10-11 March 2022), organized by Monika Michalowska and Edit Anna Lukacz from the University of Lodz.

You may find the conference details and program here:

Below is a brief abstract of my talk. If you are interested in the longer version of this paper, feel free to ask me at:

Thinking and Believing the Impossible: Medieval Reflections onOpinabiles and Inopinabiles Impossibilities

A large number of medieval logical sources dating from the end of the twelfth century up to the first half of the fourteenth century connect “impossibility” to epistemological and psychological concepts, such as thinkabilitybelievability, and imaginability. Several authors, mainly those interested in the logic of counter-possibles and/or in arguments including impossible premises, approach this theme by exploring the distinction between believable and unbelievable impossibilities (impossibile opinabile vs. inopinabile). In my presentation, I investigate the philosophical origin of the concept of believable impossibilities, wherein I link it to the growing reflection on Aristotle’s logic and to the development of ars obligatoria in the thirteenth and fourteenth centuries. I also show how the distinction between natural or nomological impossibilities on the one hand and epistemic or doxastic impossibilities on the other is applied by early 14th-centuries authors, such as Walter Burley, Richard Kilvington, and others, in disciplines other than logic, for example, theology, ethics, and natural philosophy.

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