The Deviance in Deviant Causal Chains

Causal theories of action, perception and knowledge are each beset by problems of so-called deviant causal chains. For each such theory, counterexamples are formed using odd or coincidental causal chains to establish that the theory is committed to unpalatable claims about some intentional action, about a case of veridical perception or about the acquisition of genuine knowledge. Unless the theories in question can establish a principled reason to reject all and only the deviant chains, the theories will have failed to successfully account for the phenomenon under consideration. I know of no successful attempt to identify what is deviant about the causation in these chains.