We discuss how analysis of contemporary artworks has shaped philosophical theories about the concept of art, the ontology of art, and artistic media. The rapid expansion, during the contemporary period, of the kinds of things that can count as artworks has prompted a shift toward procedural definitions, which focus on how artworks are selected, and away from definitions that focus exclusively on artworks’ features or effects. Some contemporary artworks challenge the traditional art–ontological dichotomy between physical particulars and repeatable entities whose (...) occurrences are physical particulars. And nontraditional techniques and materials employed in contemporary art violate the boundaries of conventional media, prompting a rethinking of what artistic medium might be. (shrink)