 As explained above, advocates of the DN model would not regard this diagnosis as very illuminating, unless accompanied by some account of causation that does not simply take this notion as primitive. (Salmon in fact provides such an account, which we will consider in  Section 4.)  We should note, however, that an apparent lesson of  (4)  and  (5)  is that the regularity account of causation favored by DN theorists is at best incomplete: the occurrence of c, e, and the existence of some regularity or law linking them (or x’s having property P and x’s having property Q and some law linking these) is not a sufficient condition for the truth of the claim that c caused  or x’s having P is causally or explanatorily relevant to x’s having Q. More generally, if the counterexamples  (4)  and  (5)  are accepted, it follows that the DN model fails to state sufficient conditions for explanation. Explaining an outcome isn’t just a matter of showing that it is nomically expectable.