The four principal competing substance ontologies are substratum theory, bundle theory, primitive substance theory, and hylomorphism. Both historically and in the recent literature, most arguments pertaining to these four theories have been developed under the assumption that only one of them can be true. However there is room in this debate for various forms of pluralism: mild pluralism here refers to the view that while only one of these four theories is true of our world, there is at least one (...) other possible world in which a different substance ontology obtains; moderate pluralism refers to the view that while only one of these four theories is true of our world, there is at least one other possible world in which multiple substance ontologies obtain ; and extreme pluralism refers to the view that our own actual world contains substances belonging to different substance ontologies. In this paper I lay out a novel argument for a version of extreme pluralism. (shrink)

The question of whether there could be a physical object that is necessarily constantly active has a long history, and it has recently arisen again in the literature on dispositions. I examine and critique two proposals for affirming the possibility of such an object. I then advocate a third option, one which is workable if paired with natural-kind essentialism. Finally I briefly outline three possible implications of this view for wider debates concerning the ontology of dispositions and natural kinds.

The debate between relational versus constituent substance ontology is longstanding and ongoing. In the contemporary literature it is mostly taken for granted that any version of hylomorphism must count as a constituent substance ontology. Here I argue that a certain sort of relational substance ontology could also legitimately be labeled hylomorphic, and in fact that relational substance ontologists have some good reasons to affirm this version of hylomorphism.