Abstract

One of the points of principle made by Cartwright is that the fundamental laws do not describe reality because they are always employed together with ceteris paribus clauses, the implication being that ceteris paribus assumptions always have dire consequences. We here wish to offer a dynamical interpretation of ceteris paribus laws in terms of their stability or fragility. On this interpretation, the consequences of ceteris paribus assumptions become concretely dependent on the nature of the laws under consideration and cannot be decided in a blanket fashion a priori. Using insights from nonlinear dynamical systems theory, we shall put forward the idea that any assumption of the general validity or invalidity of ceteris paribus laws amounts to a stability or fragility assumption, respectively. We shall then argue that it is in certain cases possible to relativise the consequences of ceteris paribus assumptions in a concrete way. We shall also indicate briefly how the same principle applies to Cartwright's arguments concerning composition of causes and approximations. Overall, our intention is to suggest a framework within which Cartwright's intuitions about the fundamental laws of physics could be grounded.