Kaarlo Jaakko Juhani Hintikka is a Finnish philosopher and logician.
Hintikka was born in Vantaa. After teaching for a number of years at Florida State University, Stanford, University of Helsinki, and the Academy of Finland, he is currently Professor of Philosophy at Boston University. The prolific author or co-author of over 30 books and over 300 scholarly articles has contributed to mathematical logic, philosophical logic, the philosophy of mathematics, epistemology, language theory, and the philosophy of science. His works have appeared in over nine languages.
Hintikka is regarded as the founder of formal epistemic logic and of game semantics for logic. Early in his career, he devised a semantics of modal logic essentially analogous to Saul Kripke's frame semantics, and discovered the now widely taught semantic tableau, independently of Evert Willem Beth. In recent decades, he has worked mainly on game semantics, and on independence-friendly logic, known for its "branching quantifiers" which he believes do better justice to our intuitions about quantifiers than does conventional first-order logic. He has done important exegetical work on Aristotle, Immanuel Kant, Ludwig Wittgenstein, and Charles Sanders Peirce. Hintikka's work can be seen as a continuation of the analytic tendency in philosophy founded by Franz Brentano and Peirce, advanced by Gottlob Frege and Bertrand Russell, and continued by Rudolf Carnap, Willard Van Orman Quine, and by Hintikka's teacher Georg Henrik von Wright. For instance, in 1998 he wrote The Principles of Mathematics Revisited which takes an exploratory stance comparable to that Russell made with his The Principles of Mathematics in 1903.