Situation Calculus Semantics for Actual Causality

The state-of-the-art definitions of actual cause by Pearl and Halpern suffer from the modest expressivity of causal models. We develop a new definition of actual cause in the context of situation calculus (SC) basic action theories. As a result, we avoid the paradoxes that arise in causal models and can identify complex actual causes of conditions expressed in first-order logic. We provide a formal translation from causal models to SC and establish a relationship between the definitions. Using examples, we show that long-standing disagreements between alternative definitions of actual causality can be mitigated by faithful modelling.