 Gaṅgeśa’s central focus is epistemology, not ontology or metaphysics, but his analyses rely on a centuries-old ontological system. In all four chapters of the Jewel, he addresses ontological issues, especially the topics of universals and of the ontological relation of qualification that is reflected in knowledge of something as qualified by a qualifier, “That’s a cow,” for instance, which would be an instance of knowledge of something qualified by the universal being-a-cow.