 We come finally to proposals that reject the abstract/concrete distinction. We can consider three cases. First, there are the nominalists who both reject abstract entities and reject the distinction as illegitimate. They focus on arguing against the formulations of the distinction proposed in the literature. A second group of eliminativists reject real objects of any kind, thereby dismissing the distinction as irrelevant; these are the ontological nihilists. A final group of eliminativists agree that there are prototypical cases of concrete objects and abstract objects, but conclude that a rigorous philosophical distinction can’t be made clearly enough to have any explanatory power (see Sider 2013, 287). This recalls Lewis’ pessimism (1986a, 81–86) about the possibility of establishing a distinction that is sufficiently clear to be theoretically interesting.