Explanatory update theory: Applications of counterfactual reasoning to causation

Abstract

A stratified view of causal reasoning is set forth; one in which the identification of counterfactual dependencies plays an important role in determining what sort of causal connection, if any, exists between two events named by a given pair of partial descriptions. A semantics for temporal counterfactuals in which events are represented at the object level is then formalized based on a syntactic form of belief updating. Counterfactuals are evaluated relative to an agent's information state, taken to include a set of initial beliefs together with additional assumptions to handle the frame problem. Inertial inferences emerge as a side-effect of requiring minimal information change between states of the world in some chronicle. A chronicle is, in addition, assumed minimal with respect to an explanatory preference that minimizes the set of beliefs that are not part of an agent's initial set of beliefs or are not supported by some body of law-like knowledge. A number of epistemic preferences that underly the choice of alternative worlds in accommodating a counterfactual supposition are then examined ranging over types of knowledge, locality of action, and time. This leads to a semantics for causation.