Discussive Logic

A logical framework developed by Polish logician Stanisław Jaśkowski in 1948, also known as “discursive logic” or “logic of discussion.” It was designed to model the reasoning of a group of participants who may hold contradictory opinions. In discussive logic, a proposition is considered true in the discussion if it is true from the perspective of at least one participant. This allows the discussion as a whole to be consistent even when individual participants contradict each other. It is a paraconsistent logic because contradictions can occur without trivializing the discourse. Discussive logic has applications in multi-agent systems, legal reasoning, and dialogue modeling. In casual online use, “discussive logic” might be misapplied to mean “the logic of having a discussion,” but technically it’s a specific formal system. The term is often invoked to justify contradictory consensus: “In discussive logic, both views can be valid in the group.”

Example: “In a heated thread, one user said, ‘You two are contradicting each other, so at least one is wrong.’ Another cited discussive logic: ‘Not necessarily. In a discussion with multiple agents, contradictory propositions can both be accepted as valid from different perspectives. That’s the point of discursive logic.’”

Discussive Logic by Dumu The Void May 27, 2026