How to define a thing? Problems of concreteness criteria

Abstract

For reism in its ontological aspect, it is crucial to define the concept of a thing. The definitions of this concept offered by Tadeusz Kotarbiński refer to criteria such as location in time and space, being physically some, being inert. We can compare these definitions with the various definitions of the notion of concrete object that operate within contemporary analytical ontology. In both cases, the aim is to exclude from the scope of a given concept, entities bearing the marks of abstractness. There is a close relationship between the contemporary concept of the concrete and the concept of the thing central to reism. However, the definitions offered do not give us adequate criteria to definitively exclude from the realm of things, or concrete objects, entities that are otherwise assumed to be abstract. This means that the reist and the nominalist are deprived of a good criterion to distinguish things or concrete objects from abstract objects. Moreover, Kotarbinski's definitions and those of contemporary analytic philosophers may be too restrictive and exclude from the domain of the concrete some entities postulated by science. These problems may suggest the need for a deeper reconsideration of the abstract-concrete distinction, particularly its often presupposed dichotomous nature.