Using Models to Represent Reality

1. Introduction. There has recently been an increase in interest in the role of models in science, of which the Pavia workshop on model-based reasoning is a manifestation. One result of this increased attention has been a proliferation of views on what models are and how they are used in science. In this presentation I will 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. My conclusion will be that models play a much larger role in science than even the most ardent enthusiasts for models have typically claimed. Modeling, on my view, is not at all ancillary to doing science, but central to constructing scientific accounts of the natural world. When I say I seek an interpretation of the nature and roles of models in science, I allow that other interpretations are possible. There is no unique essence to the nature of models that might be revealed by philosophical analysis. Nevertheless, I think my interpretation is better than some others, and I will attempt to convince you that this is so.