Electronic Thesis and Dissertation Repository

Thesis Format



Doctor of Philosophy




Robert DiSalle


The present work is a critical examination of the Powerful Qualities Ontology. Categoricalism affirms that intrinsic properties are quiddistic or qualitative in nature, and Pure Powers Theory affirms that they are by nature powerful. The Powerful Qualities Ontology, though, affirms that intrinsic properties are both qualitative and powerful, and that by being a more robust ontology than both Categoricalism and Pure Powers Theory, it promises to account for more phenomena and solve more problems than these rival theories. Despite its advantages, however, I challenge the feasibility of the Powerful Qualities Ontology. In chapter 1, I define important terms and provide a topography of the general debate on powers. In chapter 2, I discuss Martin and Heil’s Identity Theory, which is the standard account of the Powerful Qualities Ontology. I also discuss Jacobs’ Truthmaking View, which is supposed to be a restatement of Identity Theory. In chapter 3, I attempt to undermine Strawson’s case for Identity Theory. In chapter 4, I discuss Giannotti’s notion of aspects, which he introduces for the purpose of further articulating the Powerful Qualities Ontology. I also examine his Dual Aspect Account of powerful qualities. In chapter 5, I discuss Taylor’s collapse argument against Identity Theory. Taylor has argued that Identity Theory collapses into the Pure Powers View, and while I agree with him in important respects, I raise some doubts as to whether he is successful in establishing his conclusion. In chapter 6, I examine a couple of Grounding Theories of powerful qualities, and attempt to show how they are inadequate with respect to fundamental conceptual issues. Throughout the present work, I challenge the feasibility of several versions of the Powerful Qualities Ontology, but in chapter 7, I discuss topics relevant for future work on powerful qualities, as well as powers in general. Here I discuss alternative ontologies to Identity Theory, and different theories regarding the laws of nature that are relevant to powers ontologies. I conclude by suggesting that Powers Theorists should seriously consider more robust powers ontologies, as they are more promising than parsimonious ones in accounting for more phenomena and solving more problems.

Summary for Lay Audience

This dissertation is a philosophical investigation into the nature of properties. In ordinary discourse, we talk about different kinds of properties. We acknowledge that there are qualities (e.g., shape, colour, chemical composition), which pertain to what things are like. We also acknowledge that there are powers (e.g., fragility, combustibility, radioactivity), which pertain to how things behave. Different philosophical views assert that all the fundamental or natural properties of the world belong to one of these categories. Categoricalism asserts that properties are qualitative in nature, whereas Pure Powers Theory asserts that properties are powers by nature. Powerful Qualities Ontology, however, asserts that properties are both qualitative and powerful. By affirming that properties are both qualitative and powerful, the Powerful Qualities Ontology promises to solve more problems than both Categoricalism and Pure Powers Theory, without suffering from the same disadvantages as these theories. However, despite the advantages it promises, I challenge the feasibility of the Powerful Qualities Ontology. I mainly do so by philosophically evaluating several significant versions of the theory, arguing that the theory is vulnerable to deep conceptual issues. Theories of properties, such as the Powerful Qualities Ontology, have implications for how we can integrate our philosophical theories with our scientific theories and practice. Our scientific understanding regarding fundamental physics and the laws of nature are especially relevant to our understanding of properties. However, to this end, I suggest that theories that are more robust than the Powerful Qualities Ontology should be seriously considered. More robust theories, such as Dualism (i.e., the view that there are fundamental qualities and fundamental powers), are more promising than the Powerful Qualities Ontology with respect to the integration of our philosophical and scientific theories.