Are laws of nature consistent with contingency?

Abstract

Are the laws of nature consistent with contingency about what happens in the world? That depends on what the laws of nature actually are, but it also depends on what they are like. This latter is our concern here. Different philosophic views give different accounts of the sort of thing a law of nature is. We shall look at three that are widely endorsed: ‘Humean’ regularity accounts, laws as relations among universals, and disposition/powers accounts. Our question is, given an account of what laws are, what follows about how much contingency, and of what kinds, laws allow? Of the three types we shall look at, powers stand out as especially apt for admitting contingency, or so it would appear from conversations we've been engaged in, both with powers advocates and with powers opponents. Our investigation here suggests that this is not so. A powers account of laws may admit contingency but it need not. Conversely, the other accounts may rule out contingency but they need not. In all three cases, we shall argue, the root idea of what laws are does not settle the issue of whether they allow contingency. Advocates of the different accounts may argue for one view or another on the issue, but (at least as we understand the accounts) this will be an add-on rather than a consequence of the basic view about what laws are.