LIRa session (online only): Ilaria Canavotto and Eric Pacuit

Speaker: Ilaria Canavotto and Eric Pacuit

Date and Time: Thursday, April 23rd 2020, 16:30-18:00, Amsterdam time.

Venue: online

Title: Merging STIT and counterfactual logic

Abstract. STIT logics and their various extensions have been used to clarify complex moral and legal ideas and to represent game-theoretic situations. Although both of these applications involve counterfactual reasoning, only a few STIT logics explicitly incorporate reasoning about counterfactuals. In this talk, we present a proposal that merges a standard logic of counterfactuals with a STIT logic. Taking a cue from the literature on causal models, we do this by developing and axiomatizing a STIT logic with action types, instants and deviant choices, where a choice is deviant when its performance violates some underlying causal laws, social or legal norms, or other “rules of the game”. In order to provide a semantics for counterfactuals, we discuss three key intuitions supporting increasingly demanding definitions of similarity between possible histories: the rewind intuition, the causal independence intuition and the no forgetting intuition. In the second half of the talk, we explore an application to the epistemic foundations for backward and forward induction.