A Problem for Fine Individuation and Artist Essentialism

Fine Individuation says it is impossible for distinct people who are not collaborating on a work of art to produce one and same artwork. This is an intra-world thesis, but is necessarily true, if true at all. Author Essentialism says it is impossible for someone else to produce one and the same work of art produced by some actual artist. This is an alleged necessary truth regarding cross-world relations. Both theses have been vigorously defended. I argue here that both are false, but for reasons that are entirely novel.