Title: Relevance in the Logic of Imagination

Abstract: Reality-oriented mental simulation is a kind of imagination. The working assumption is that, when trying to determine whether a match would light if struck, one initially imagines striking the match and, together with relevant beliefs imported into the imaginative scenario, mentally simulates what would happen. But what beliefs count as relevant in this context? And how is relevance to be modelled in the logic of imagination?

Different answers to these questions yield different approaches in the logic of imagination, including possible worlds approaches (Lewis 1978, Heintz 1979, Niiniluoto 1985, Costa–Leite 2010), impossible worlds approaches (Berto 2014, Priest 2016a, Priest 2016b, Berto 2016, Berto 2017, Berto and Jago 2019), and subject matter approaches (Berto 2018a, Berto 2018b). In the first part of the talk, I’ll argue that these approaches do not adequately model relevance. In the second, I’ll propose a new approach and argue that, whilst an improvement, it is not without issue. I’ll introduce a significant problem for the approach and show how I’ve tried to solve it.