Taking its cue from the philosopher Nelson Goodman's suggestion that we ask not "what is art?", but "when is art?", this graduate seminar explores questions related to the temporal boundaries of works of art. Can works subside from the category of art into that of mere document or vice versa? Does "art" inhere primarily in preparatory sketches, a discrete physical object, the event of making, the residue of production, posterior documentation, or the act of reception? What kinds of ethical and philosophical problems are posed by the conservation of ephemeral works? How might the distribution, deferral, or reanimation of a work function as critical resistance to systems of institutionalization and commodification? This class takes up such questions through case studies from the 1960s to the present that problematize the stability of the work of art, whether through instruction-based propositions, performances and practice-oriented interventions, transitory forms and materials, or copies and fakes. While our focus will be on recent art practices, we will also consider scholarship from disparate chronological periods and disciplines in order to theorize the multiple temporalities of contemporary art.