 Premise OD4 can be motivated in much the same way as OD7. If baseballs don’t cause anything to happen, then we have no good reason to believe in them, in which case we should accept OD4. One might also give a more direct defense of OD4 by appealing to the controversial Eleatic Principle (a.k.a. Alexander’s Dictum), according to which everything that exists has causal powers. Together with the plausible assumption that if baseballs don’t cause anything it’s because they can’t cause anything, the Eleatic Principle entails  OD4.[48]