1924 – 1988
Stig Kanger (1924–1988) was a Swedish logician and philosopher at Uppsala University, best known for independently developing possible-worlds semantics for modal logic around the same time as Kripke, and for his rigorous formal analysis of normative relations and rights. His work bridged mathematical logic, deontic logic, and the theory of action.
Independently developed possible-worlds semantics for modal logic (1957), anticipating Kripke semantics
Formalized Hohfeldian rights relations using first-order deontic logic
Contributed foundational work on the logic of action and normative systems
Analyzed future contingencies and their interaction with deontic operators in temporal-modal frameworks
Influenced Scandinavian traditions in logic, legal theory, and normative reasoning