Abstract

Summary It is shown that, besides differences in emphasis on structural and developmental aspects, there is far reaching agreement between the views of Nagel and Lakatos on structure and development of science. I argue that both views can interact very fruitfully, and by way of illustration a confrontation of Nagel's notion of a model with Lakatos' notion of a positive heuristic is pursued in some detail. The conclusion is that for microscopic theories, a Lakatosian positive heuristic is exactly the same entity as a substantive model in the sense of Nagel, but that for phenomenological theories there is (as yet) no such structural concept as a model available that can be identified with a Lakatosian positive heuristic