 This can be taken as a stipulation about how ‘overdetermined’ is to be understood in the argument, thus preempting nebulous debates about whether satisfying these five conditions suffices for “real” or “genuine” overdetermination. To say that o1 is causally relevant to o2’s causing e is to say that o1 enters into the explanation of how o2 causes e to occur in one of the following ways: by causing o2 to cause e, by being caused by o2 to cause e, by jointly causing e together with o2, or—where o2 is a plurality of objects—by being one of  them.[45] 