The Colloquium of Logic is organized by the Portuguese Logic Society and aims to promote the research and knowledge in this field, from mathematical logic to philosophical logic as well as logic for artificial intelligence and theoretical computer science. The talks of the Colloquium of Logic will be held in a hybrid way. The talks will take place, unless otherwise stated, at the Mathematics Department of Técnico ULisboa, room 3.10, and online.
Joint colloquium between the Brazilian Logic Socity and the Portuguese Logic Society
- João Marcos (Universidade Federal de Santa Catarina), “Bilateralism: When Two Sides Make a Difference”, 22 de outubro de 2026, 15h, https://meet.google.com/bzt-iwxf-kxs
Abtract: In logic, bilateralism is the view that reasoning involves two basic kinds of judgment: assertion and denial. But does every formalism that recognizes this distinction provide a genuinely two-sided account of logical consequence? I argue that this is not the case. What matters most is whether the cognitive attitudes of acceptance and rejection are represented independently and whether the logic explains how they constrain one another. Starting from relations of compatibility between judgments of assertion and denial, I introduce a framework for bilateral closure and two-dimensional consequence. This framework treats a logical theory as a coordinated pair of positive and negative commitments and reveals familiar departures from standard consequence as one-sided aspects of a richer bilateral structure
See past talks of the Colloquium of Logic on Events.