The metatheoretical framework of William of Ockham's modal logic
pp. 137-147
in: Jenny Pelletier, Magali Roques (eds), The language of thought in late medieval philosophy, Berlin, Springer, 2017Abstract
Ockham has a very particular definition of modality: every term that is predicable of a whole sentence is a modal term. His definition reaches well beyond "necessary," "possible," "contingent" and "impossible," including predicates such as "known" and "believed," but also "written" and "spoken." He provides a general framework for inferences including every term covered by his definition of modality. However, there is a proper modal syllogistic in Ockham only for the Aristotelian modalities, that combines two distinct semantic apparatus, constituted by Ockhamist modal predicates, on the one hand, and by modal and modally modified copulae, on the other. For the development of a syllogistic for the Aristotelian modalities, both are needed. There is no similar apparatus for other modalities in Ockham.
