ABSTRACT
This chapter argues for at least one important role for fi ctions in science, especially in the computationally intensive sciences of complex physical systems-in computer simulation. Fictions, I will argue, are sometimes needed for extending the useful scope of theories and model-building frameworks beyond the limits of their traditional domains of application. One especially interesting way in which they do this is by helping to enable model builders to sew together incompatible theories and apply them in contexts in which neither theory by itself will do the job.
