Probabilistic Actual Causation

Actual causation - the sort of causal relation asserted to hold by claims like 'the Chicxulub impact caused the Cretaceous-Paleogene extinction event', 'the H7N9 virus outbreak was caused by poultry farmers becoming simultaneously infected by bird and human 'flu strains', and 'Mr. Fairchild's suffering mesothelioma was caused by his exposure to elevated levels of asbestos' - is of significance to philosophers, scientists, historians, and tort and criminal lawyers. Progress has been made in explicating the actual causal relation in the deterministic case - where causes bring about their effects with certainty - by means of the use of structural equation models and causal graphs. In this paper, I seek to make similar progress concerning the probabilistic case - where causes bring about their effects merely as a matter of probability - by using probabilistic causal models and associated causal graphs.