There seems to be at least some scope for Thomson to resist this move (Kamm 1992: 47). Those who believe that Falling Person has a right not to be killed must believe that, unlike a stone, Falling Person is a moral agent, assuming that only moral agents have rights. Restricted to moral agents, Thomson’s view avoids labelling stones rights-violators. Moreover, it is plausible that one can fail in a duty without exercising one’s agency, and also plausible that one can fail in a duty even if one is unable to fulfill that duty. For example, if I forget to meet you for lunch, despite promising to do so, I fail in my duty to keep my promise even if my forgetting is not a result of my agency, and I have no control over my forgetting.