 The possibility of fundamental determinables also bears on various first-order metaphysical topics. For example, Paul (2002, 2012) endorses a one-category ontology (‘mereological bundle theory’), on which properties and relations are fundamental, and property composition is “the fundamental glue” (2012: 242). Paul allows that determinables might be among the fundamental properties and relations (note 22), and moreover suggests that such posits may be required to accommodate theories couched in terms of properties and relations which are “extremely abstractly specified” (2012: 245).