  Although Abhidharma philosophical views on the kinds of entities that have only nominal existence range widely, it is generally agreed that persons or individuals are always to be taken as nothing more than  merely conventional designations established on the basis of the five aggregates, the domains of perceptual activity, and their respective  elements. Note, however, that Abhidharma philosophers do not deny the physical reality of aggregated entities and persons. Indeed,  materiality or form (rūpa), which is also one of five  collections of aggregates, is generally considered to be an external, non-mental reality. Rather, the two-tiered approach to the existence  of phenomena, which distinguishes between substantial and nominal  existents, is meant to reject not the existence of extra mental  entities proper, but rather the existence of all partite entities  such as chairs, pots, and tables (cf. Kapstein 2001, 90 and  passim; Siderits 2003, 33 and passim).