 The refusal to characterize the abstract/concrete distinction while maintaining that both categories have instances might be called the way of primitivism, whenever the following condition obtains: a few predicates are distinguished as primitive and unanalyzable, and the explanatory power rests on the fact that other interesting predicates can be defined in terms of the primitives and that interesting claims can be judged true on the basis of our intuitive understanding of the primitive and defined notions. Thus, one might take abstract and concrete as primitive notions. It wouldn’t be an insignificant result if one could use this strategy to explain why abstract objects are necessarily existent, causally ineffiacious, non-spatiotemporal, intersubjective, etc. (see Cowling 2017: 92–97).