Effective field theories, reductionism and scientific explanation

Effective field theories have been a very popular tool in quantum physics f or almost two decades. And there are good reasons for this. I will argue th at effective field theories share many of the advantages of both fundamenta l theories and phenomenological models, while avoiding their respective sho rtcomings. They are, for example, flexible enough to cover a wide range of phenomena, and concrete enough to provide a detailed story of the specific mechanisms at work at a given energy scale. So will all of physics eventual ly converge on effective field theories? This paper argues that good scient ific research can be characterised by a fruitful interaction between fundam ental theories, phenomenological models and effective field theories. All o f them have their appropriate functions in the research process, and all of them are indispensable. They complement each other and hang together in a coherent way which I shall characterise in some detail. To illustrate all t his I will present a case study from nuclear and particle physics. The resu lting view about scientific theorising is inherently pluralistic, and has i mplications for the debates about reductionism and scientific explanation. (C) 2001 Elsevier Science Ltd. All rights reserved.