 Putting aside the issues raised in the previous section, the SR model embodies several generic assumptions of ongoing philosophical interest. In particular the model assumes that (i) explanations must cite causal relationships and that (ii) causal relationships are fully captured by statistical relevance (or conditional dependence and independence) relationships. While (i) is a matter of current controversy, (ii) is clearly false. As a substantial body of  work[5]  has made clear, causal relationships are greatly underdetermined by statistical relevance relationships, even given additional assumptions. For example, a structure in which B is a common cause of the joint effects A and C implies (assuming the Causal Markov assumption which is the appropriate generalization of Salmon’s assumptions connecting causation and probability) implies the same statistical relevance relations as a chain structure in which A causes B which causes C. 