Defaults and Normality in Causal Structures
  A serious defect with the Halpern-Pearl (HP) definition of causality is
repaired by combining a theory of causality with a theory of defaults. In
addition, it is shown that (despite a claim to the contrary) a cause according
to the HP condition need not be a single conjunct. A definition of causality
motivated by Wright's NESS test is shown to always hold for a single conjunct.
Moreover, conditions that hold for all the examples considered by HP are given
that guarantee that causality according to (this version) of the NESS test is
equivalent to the HP definition.
