Models, fictions, and realism: Two packages

Some philosophers of science-myself included-appeal to fiction as an interpretation of the practice of modeling. This raises the specter of an incompatibility with realism, since fiction making is essentially nontruth regulated. I argue that the prima facie conflict can be resolved in two ways, each involving a distinct notion of fiction and a corresponding formulation of realism. The main goal of the essay is to describe these two packages. I comment also on how to choose between them.