Powerful Properties, Powerless Laws

A familiar choice-point in the laws of nature debate is whether the laws do any important metaphysical work. Some philosophers, such as Fred Dretske, Michael Tooley, David Armstrong, and Tim Maudlin, argue that the laws have very important metaphysical work to do because the way the world is depends on the laws. Others, such as David Lewis, Barry Loewer, Jonathan Cohen and Craig Callender, and Alexander Bird argue that the laws do not have important metaphysical work to do because the laws depend on the way the world is. According to the traditional formulation of the Best System Account (BSA), the most basic laws of nature (those that are the aim of ideal, final physics) are those propositions which, taken together, constitute the simplest and most informative description of the world. There are two central, but independent, features of this view. One is that the laws are mere systematizations of the fundamental ontology; they are not metaphysically ‘weighty’ and do not govern. The other is that the laws depend upon only categorical properties and relations. In this chapter I explore the consequences of accepting the first feature while rejecting the second. That is, I explore a best sys-tem account of laws that depends upon potencies. (For the purposes of this chapter, I suppose the fundamental properties are potencies: properties that are essentially dispositional.) I argue that a BSA grounded in potencies is preferable to a BSA grounded in categorical properties. Laws of nature, on this view, are those propositions that constitute the simplest and most informative description of potencies.