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. (shrink)

Although we do not know exactly how many people die each year of malnutrition or related health problems, the number is very high, in the millions. By giving money to support famine relief efforts, each of us could save at least some of them. By not giving, we let them die.

Is it worse to kill someone than to let someone die? It seems obvious to common sense that it is worse. We allow people to die, for example, when we fail to contribute money to famine-relief efforts; but even if we feel somewhat guilty, we do not consider ourselves murderers. Nor do we feel like accessories to murder when we fail to give blood, sign an organ-donor card, or do any of the other things that could save lives. Common sense (...) tells us that, while we may not kill people, our duty to give them aid is much more limited. Some philosophers, however, have argued that common sense is wrong about this. They have defended the Equivalence Thesis, which says that killing and letting die are equally bad. This is a more specific version of the idea that there is no moral difference between making something happen and allowing it to happen. The Equivalence Thesis is a radical conception that would require changes in our ordinary moral beliefs. If it is true, then obviously our duty to give aid is much stronger than we commonly assume. But our views about other matters, such as euthanasia, will also be affected. Many people believe that “passive euthanasia”--allowing terminal patients to die, rather than pointlessly prolonging their lives--is sometimes permissible; but they also believe that killing patients is always wrong. If the Equivalence Thesis is true, this combination of beliefs is inconsistent. The idea behind the Equivalence Thesis is not that every individual case of letting die is equally as bad as every individual case of killing. Obviously, if we compare an ordinary murder--say, a man killing his wife out of jealousy--with the actions of a physician who humanely permits a suffering patient to die, the murder is much worse. Rather, the idea is that the difference between killing and letting die does not itself make a difference to the moral assessment of the actions. Other factors may still be important. (shrink)