Hintikka Jaakko (b.1929), Finnish philosopher with contributions to logic, philosophy of mathematics, epistemology, linguistics and philosophy of language, philosophy of science, and history of philosophy. His work on distributive normal forms and model set techniques yielded an improved inductive logic. Model sets differ from Carnap’s state-descriptions in being partial and not complete descriptions of ‘possible worlds.’ The techniques simplified metatheoretical proofs and led to new results in e.g. probability theory and the semantic theory of information. Their main philosophical import nevertheless is in bridging the gap between proof theory and model theory.
Model sets that describe several possible ‘alternative’ worlds lead to the possible worlds semantics for modal and intensional logics. Hintikka has used them as a foundation for the logic of propositional attitudes (epistemic logic and the logic of perception), and in studies on individuation, identification, and intentionality. Epistemic logic also provides a basis for Hintikka’s logic of questions, in which conclusiveness conditions for answers can be defined. This has resulted in an interrogative model of inquiry in which knowledge-seeking is viewed as a pursuit of conclusive answers to initial ‘big’ questions by strategically organized series of ‘small’ questions (put to nature or to another source of information). The applications include scientific discovery and explanation. Hintikka’s independence-friendly logic gives the various applications a unified basis. Hintikka’s background philosophy and approach to formal semantics and its applications is broadly Kantian with emphasis on seeking-andfinding methods and the constitutive activity of the inquirer. Apart from a series of studies inspired by Kant, he has written extensively on Aristotle, Plato, Descartes, Leibniz, Frege, and Wittgenstein. Hintikka’s academic career has been not only in Finland, chiefly at the University of Helsinki, but (especially) in the United States, where he has held professorships at Stanford, Florida State, and (currently) Boston University. His students and co-workers in the Finnish school of inductive logic and in other areas include Leila Haaparanta (b.1954), Risto Hilpinen (b.1943), Simo Knuuttila (b.1946), Martin Kusch (b.1959), Ilkka Niiniluoto (b.1946), Juhani Pietarinen (b.1938), Veikko Rantala (b.1933), Gabriel Sandu (b.1954), Matti Sintonen (b.1951), and Raimo Tuomela (b.1940). See also EROTETIC LOGIC, HINTIKKA SET, INDUCTIVE LOGIC , MODEL THEORY, POSSIBLE WORLDS , PROOF THEORY. M.T.S.