Killing John to save Mary: a defence of the moral distinction between killing and letting die

Introduction This paper defends the moral significance of the distinction between killing and letting die. In the first part of the paper, I consider and reject Michael Tooley’s argument that initiating a causal process is morally equivalent to refraining from interfering in that process. The second part disputes Tooley’s suggestion it is merely external factors that make killing appear to be worse than letting die, when in reality the distinction is morally neutral. Tooley is mistaken to claim that we are permitted to kill bystanders who had no fair chance to avoid being at risk of harm. We can support the significance of the killing / letting die distinction by considering the difference between what we are permitted to do in self-defence against those who are going to kill us, and what we can do against those who are going to let us die. I also suggest that we are less responsible for the deaths we allow than for the deaths that we cause, since we do not make people worse off for our presence in cases where we fail to save them