Abstract

The Logic of Port-Royal, first published in 1662 by the Jansenists Antoine Arnauld and Pierre Nicole, is a work that underlines the inadequacies of the traditional logic. Traditional logic, which included the texts of Aristotle's Organon and the works of the scholastics, was experiencing a mild renaissance in the seventeenth century following its outright and brutal discrediting by the humanists of the previous two centuries. Arnauld and Nicole introduce a fairly original system of logic that attempts to remedy the shortcomings of the revived tradition; they dismiss the Aristotelian "Categories", "Predicables", and "Topics", ignore the scholastic "Doctrine of Terms and Consequence", and suggest a single "General Principle" by means of which the validity of all arguments can be decided. The Principle is based on a notion of containment, divided into entendue and comprehension , which applies to all terms. Because the notion of containment is linked to the objective reality of Cartesian ideas, the authors can claim that their system of logic properly describes reality. The General Principle also suggests that terminist logic is logically and epistemologically prior to sentential logic because, Arnauld and Nicole claim, it governs the Dictum de Omni et Nullo and the Nota Notae. The self-evidence of the two dicta confirmed the validity of all syllogisms of the first figure; furthermore, all syllogisms of other figures could be reduced to one of the first figure. With the General Principle, however, there is no need for such reduction to the first figure. This additional result makes the theorem of sentential logic, "$\supset$r)$\approx$$\supset$-q)", which was needed for the reductions of Baroco and Bocardo, unnecessary. The fact that no theorem of sentential logic is needed to underline term logic guarantees the autonomy of the latter