Individual contributions to collective harm: how important is causation?

ABSTRACT In the last chapter of Responding to Global Poverty, Barry and Øverland argue that there are moral reasons against overdetermining harm. They define overdetermining harm as conduct that makes no apparent difference to the occurrence of harm but is of the type that brings about harm when many people engage in it. An individual’s greenhouse gas emissions are a prime example. Barry and Øverland’s proposal is that reasons to refrain from overdetermining conduct exist because of the probability that the agent will become an element of the set of actual conditions that in fact brings about the outcome. This paper aims to show that by focusing on causation-related considerations, Barry and Øverland base their account on the wrong reasons. More specifically, I argue that this focus leads to three difficulties. First, the account is not able to justify overdetermination-based constraints in all overdetermined harm cases. Second, the probability of being in the set may be too easily outweighed by the costs of refraining and the benefits the conduct would bring. Third, the probability of being in the actual set may not be highly morally relevant, given that an individual’s contribution to the harm caused by the set can only be very limited in large-scaled overdetermined harm cases. Barry and Øverland are right in arguing that it is important to undermine scepticism about the wrongness of overdetermining harm. However, a non-causation-based account might be more successful in doing so.