ree Kinds of Idealization

Philosophers of science increasingly recognize the importance of idealization: the intentional introduction of distortion into scientific theories. Yet this recognition has not yielded consensus about the nature of idealization. e literature of the past thirty years contains disparate characterizations and justifications, but little evidence of convergence towards a common position. Despite this lack of convergence, consensus has clustered around three types of positions, or three kinds of idealization. While their proponents typically see these positions as competitors, I will argue that they actually represent three important strands in scientific practice. Philosophers disagree about the nature of idealization because there are three major reasons scientists intentionally distort their models and theories; all three kinds of idealization play important roles in scientific research traditions. e existence of three kinds of idealization means that some classic, epistemic questions about idealization will not have unitary answers. We cannot expect a single answer to questions such as: What exactly constitutes idealization? Is idealization compatible with realism? Are idealization and abstraction distinct? Should theorists work to eliminate idealizations as science progresses? Are there rules governing the rational use of idealization, or should a theorist’s intuition alone guide the process? However, the three kinds of idealization share enough in common to allow us to approach the answers to these questions in a unified way. e key is to focus not just on the practice and products of idealization, but on the goals governing and guiding it. I call these goals the