 This conception has two prima facie advantages. The first advantage is that it offers a straightforward answer to the ER-Problem (or SR-problem if the focus is on scientific representation), and one that accounts for surrogative reasoning: the mappings between the model and the target allow scientists to convert truths found in the model into claims about the target system. The second advantage concerns the applicability of mathematics. There is a time-honoured position in the philosophy of mathematics which sees mathematics as the study of structures; see, for instance Resnik (1997) and Shapiro (2000). It is a natural move for the scientific structuralist to adopt this point of view, which then provides a neat explanation of how mathematics is used in scientific modelling.