Using Models to Represent Reality

In this paper I develop a unified interpretation of the nature and role of models in science. Central to this interpretation is an understanding of the relationships between models and other elements of an understanding of science, particularly theories, data, and analogy. I begin by criticizing a standard interpretive or instantial view of models, derived from mathematical logic, as not being adequate for empirical science. I then go on to develop a representational view of models which, I argue, is much more adequate to the needs of empirical science. I conclude that scientific reasoning is to a large extent model-based reasoning. It is models almost all the way up and models almost all the way down.