Published online by Cambridge University Press: 31 January 2023
In earlier publications Jaakko Hintikka has introduced the interrogative model of inquiry and studied some of its applications.1 At its simplest, the interrogative model takes the form of a game between a player known as the Inquirer and a source of information we call Nature. The inquirer is trying to derive a conclusion C from a given set of premises T by standard deductive means augmented by additional information gained from Nature. (We can think of C as a set of formulas related disjunctively to each other.) The inquirer may obtain this additional information by means of questions put to Nature. The answers to these questions, when available, are then added to the premise set T. When a question is answerable but no true answer is available, Nature may respond with a false answer.
The deductive steps employed are subject to certain limitations. For instance, if the derivation is being carried out in a Beth-style tableau system, we require that the deductive steps obey the subformula principle.2