Proportionality and the metaphysics of causation

This paper reexamines the case for a proportionality constraint on causation. The general idea behind the proportionality constraint is that causes need the right amount of detail. The cause needs to be detailed enough to be sufficient for the effect yet general enough to be fully relevant to the effect. The case for the proportionality constraint mainly rests on some examples. Suppose we are searching for the cause of an injury: “being hit by a red bus” is too detailed, “being hit” isn't detailed enough, but “being hit by a bus” is about right. This sort of example has undeniable intuitive appeal. However, this intuitive appeal needs to be examined with more care before jumping to conclusions about the metaphysics of causation and the mereology of causal relata. Here, I reexamine the case for a proportionality constraint on causation and compare several pragmatic explanations of our intuitions about Yablo’s examples, in particular a pragmatic explanation that notices the loose use in our naming of causal relata and a pragmatic explanation that appeals to a contrastivist account of causation.