Default Logic as a Species of Causal Reasoning

We will show that Reiter's default logic can be viewed as a particular instantiation of causal reasoning. This will be demonstrated by establishing back and forth translations between default theories and causal theories of the causal calculus under a particular nonmonotonic semantics of causal theories that will be called a default semantics. Moreover, it will be shown that Pearl's structural equation models can be viewed as default causal theories in this sense. We will discuss also some global consequences this representation could have for establishing a general role of causation in nonmonotonic reasoning.