Causes and Explanations: A Structural-Model Approach. Part II:
  Explanations
  We propose new definitions of (causal) explanation, using structural
equations to model counterfactuals. The definition is based on the notion of
actual cause, as defined and motivated in a companion paper. Essentially, an
explanation is a fact that is not known for certain but, if found to be true,
would constitute an actual cause of the fact to be explained, regardless of the
agent's initial uncertainty. We show that the definition handles well a number
of problematic examples from the literature.
