Exceptions to the laws of nature

Martin Leckey (The University of Melbourne), John Bigelow (Monash University)

In this paper, we describe an internally coherent world-view, within which there are certain things that deserve the name of ‘laws of nature’ even though they fail to fit the things that philosophers have hitherto said about laws of nature.

In particular, many philosophers have assumed that laws of nature are exceptionless regularities. And that entails that the very idea of a ‘miracle’, as an ‘exception to the laws of nature’, is internally incoherent. Our description of laws of nature, by contrast, makes it a coherent possibility that there could be exceptions to the laws of nature.

Laws of nature are, at one level, contingent; and yet they also manifestly possess a kind of necessity that is aptly called ‘natural necessity’. We analyse this ‘natural necessity’ as a species of ‘conditional necessity’. It is a necessity that is conditional on what we call the essential natures of whatever the world does happen to contain.

This part of our theory overlaps with a widely-held approach sometimes called the ‘strong theory of laws’. But to this we add a further claim, namely: that these entailments are also conditional on an absence of interference from things that lie outside what we will call the ‘natural realm’. Our primary task in this paper is to elucidate this notion of ‘the natural realm’.