 What about cases where the agent removes a safety net from beneath a falling victim, unplugs a respirator, kicks a rock out of the path of the runaway vehicle, and other similar cases? In these cases, the agent performs some action but does not act on the victim directly. Instead, she removes some barrier to a harmful sequence. Such cases are now an important part of philosophical discussion of the doing/allowing distinction, in part because of the recognition that some apparently standard cases of doing in fact involve removing a barrier. As Jonathan Schaffer (2000) has argued, in many guns, pulling the trigger fires a bullet by essentially removing a barrier. 