Abstract

The distinction between killing and letting die has been a controversial element in arguments about the morality of euthanasia and physician-assisted suicide. The killing/letting die distinction is based on causation of death. However, a number of causal factors come into play in any death; it is impossible to state a complete cause of death. I argue that John Mackie’s analysis of causation in terms of ‘inus factors,’ insufficient but nonredundant parts of unnecessary but sufficient conditions, helps us to see that moral responsibility for death cannot rest on causation alone. In specifying the cause of death, some factors can be considered alternatively as either causal factors or merely parts of the presupposed background conditions. If a factor is moved from the background field into the causal field, the result is a changed background field. Comparisons of cases of killing and letting die often do just this; hence, the cases depend on different presuppositions and the causation cannot be directly compared. Moral judgments determine how to apportion factors to the causal and background fields.