Knowing by Imagining1

This chapter explains the cognitive role of the imagination as a means to knowledge, permitting the offline use of cognitive faculties in both mental and non-mental simulation to assess counterfactual conditionals, in an analogue of online updating and prediction on the basis of new information. Other modal claims can be assessed similarly. This role involves the context of justification as well as the context of discovery. It substantiates the examples in Chapter 10, where imagination is treated as a means to knowledge. An analogy is sketched between the development of hypotheses in the imagination and the tableau method in deductive logic, which casts light on our ability to imagine an F when there is no F that we are imagining. It is suggested that such an overall cognitive role for the imagination makes sense on evolutionary grounds, including the distinction between voluntary and involuntary uses of the imagination.

Hintikka's World: Agents with Higher-order Knowledge

In this demonstration paper, we present a pedagogical tool called Hintikka's world for showing how artificial agents can reason about higher-order knowledge (an agent knows that another agent knows that...). The system provides famous AI examples such as Muddy children and Russian cards. The system also allows to implement user's own examples via the description of a Kripke model or via its generation by the generic tableau method prover MetTeL2.