 One argument against it is that it makes causation intrinsic to the pair C and E, but some cases, especially cases of double prevention, show that causation is extrinsic. Double prevention occurs when an event, call it C, prevents something that would have prevented E from happening. Intuitively, these are cases of causation. Indeed, when we look at the details we find that many everyday cases of causation have this pattern. But that C causes E does not depend on the intrinsic natures of C and E. Rather, it depends on there being some threat to E, a threat that C prevents, and the existence of threats is typically extrinsic to events.