Cartwright, Forces, and Ceteris Paribus Laws

This paper proposes a novel response to Nancy Cartwright’s famous argument that fundamental physical laws, such as Newton’s law of gravitation, are ceteris paribus: construing forces instrumentally allows such laws to apply generally, eliminating the need for ceteris paribus clauses. The instrumental construal of forces is motivated, and defended against prominent recent objections. Further, it is argued that such instrumentalism in no way undermines the role of force-laws in scientific practise, and indeed, is compatible with a robust realism about force-laws