The article investigates some general properties of universal vs. particular propositions occuring in syllogistic arguments, in order to explore the kind of interaction played by these two forms of reasoning inside cognition. The theoretical framework of our analysis is represented by recent developments of linear logic, focusing on the distinction between positive vs. negative status of logical operators (connectives and quantifiers). In the first part of the article, this distinction is introduced and applied to the analysis of the categorical propositions occurring in Aristotelian syllogism, the deductive paradigm particularly considered in psychological studies about human reasoning. In the second part of the article, an experimental re...