Realist Bundle Theory
Abstract
Philosophical theories of the nature of concrete particulars come in two basic kinds, those according to which a concrete particular consists of properties and a bearer of those properties (a substratum), and those according to which a concrete particular consists only of its properties, in a relation of compresence or concurrence. Substrata are theoretical entities defined by their explanatory functions. As such, there is not much disagreement about their nature: they are propertyless, unobservable constituents of concrete particulars that are the bearers of properties 1 and the individuators of distinct particulars. The situation is different with respect to properties. Among realists, some think properties are universals, either transcendent (Platonists) or immanent (Aristotelians), and some 2 think they are particulars (“tropes” ). Of the resultant possible positions on the nature of concrete particulars, six have been the focus of recent philosophical attention. These theories variously identify concrete particulars with (i) material substrata bearing transcendent universals, (ii) material substrata bearing immanent universals, (iii) material substrata bearing abstract particulars, (iv) bundles of transcendent universals, (v) bundles of immanent universals, and (vi) bundles of abstract particulars.