We’ve now twice encountered arguments of the following form: “c caused e” is true, but “c* caused e” is false, so it must be that “c” and “c*” denote two different causal relata. In short: where there are differences in causation, there must be differences in the causal relata. Call this the causal differences argument. This argument was used to show that token causes cannot just be regions of spacetime—for then, the ball’s rotation and its heating would be one and the same event, but the ball’s