Abstract

The seventeenth-century Spanish Dominican Cosme de Lerma authored numerous philosophical works, some ofwhich were posthumously reorganised into a Cursus philosophicus, intended as an arts course for the Dominican studia in Italy. Lerma’s philosophical project consisted in developing the doctrines proposed a century earlier by his fellow Dominican friar Domingo de Soto. Through analysing Lerma’s Compendium and Disputationes based on Soto’s Summulae and Lerma’s Commentaries on Aristotle’s Logic, this paper explores three issues: first, Lerma’s axiomatic theory of inference, including the development of Soto’s project of relevance logic (relating to the analysis of the paradoxes of implication); second, the question whether there are different degrees of validity (answered negatively by Lerma); third, Lerma’s psychology of inference, which offers an interpretation of human inferential behaviour and its limitations in terms of the scholastic theories of causation and natural agency.