   One response to the no-swapping objection, given by Campbell and Labossiere, rejects the assumption that trope swaps would make no difference to the world. For example, although the effects of “swapped” situations would be exactly similar in nature, those effects would differ in their causes (Campbell 1990, 72; Labossiere 1993, 262). Schaffer, on the other hand, denies that the trope theory is automatically committed to the possibility of trope swapping (2001). If tropes are individuated by times/locations and a counterpart theory of modality is right, then trope swapping is ruled out: 