1929 – 2015
Jaakko Hintikka (1929–2015) was a Finnish philosopher and logician widely regarded as one of the founders of epistemic logic and game-theoretic semantics. He made foundational contributions to modal logic, philosophy of language, and the philosophy of mathematics, and was a prolific interpreter of Aristotle, Kant, and Wittgenstein.
Founded epistemic logic, the formal logic of knowledge and belief
Developed game-theoretic semantics as an alternative to Tarskian truth-conditional semantics
Pioneered possible worlds semantics for modal and epistemic logic
Introduced Independence-Friendly (IF) logic, extending first-order logic to handle informational independence
Produced influential reinterpretations of Aristotle's logic and Wittgenstein's philosophy