 According to Mertz (cf. also Maurin 2011), moreover, to be able to do the unifying work for which it is introduced, compresence cannot be a universal. If it were, then if one of the concrete particulars whose constituents it joins ceases to exist, so will every other concrete particular unified by the same (universal) relation of compresence. But, as Mertz points out, “this is absurdly counterfactual!” (Mertz 1996: 190).  Nor can it be a state of affairs. For, states of affairs are in themselves complexes, and so could not be used to solve the Bradley problem.[37] It seems, then, that compresence, if understood in a way that blocks the regress, is a trope. Assuming that Bradley’s regress threatens any account according to which many things make up one unified thing (i.e., assuming that it does not only threaten the trope-bundle theorist), therefore, that there is this threat is in itself a reason to think there are tropes.