Natural Laws and Accidental Uniformities

Natural Laws and Accidental Uniformities

The Laws of Nature

Most empiricists adopted the Regularity View of Laws: laws are cosmic regularities. According to the humean tradition, there are only regularities in nature, that is, sequences of event-types, which happen in constant conjunction: whenever one occurs, it is invariably followed by the other. When, for instance, it is said that it is a law that metals expand when heated (under constant pressure), Humeans mean that there is regularity in nature according to which whenever a metal gets heated it expands. There is no necessity in this regularity because (1) it is logically possible that a metal is heated (under constant pressure) and yet it does not expand; and (2) there is nothing in the nature of a metal that makes it the case that, necessarily, it will expand when it is heated (Swartz, 2009). Yet, empiricists have had a hurdle to jump: not all regularities are causal. Nor can all regularities be deemed laws of nature. So they were forced to draw a distinction between those regularities that constitute the laws of nature and those that are, as Mill put it, 'conjunctions in some sense accidental'. The predicament that Humeans are caught in is this. Something (let's call it the property of law likeness) must be added to a regularity to make it a law of nature. In a nutshell, it can be said that the prescriptive law of nature is conceived as a basic system of moral norms, the necessity of obedience being moral. This conception is often linked with natural theology, and then the contrast is with revelation. The contents of some basic mandates, although supported by divine authority, are not specially revealed, but are supposed to be accessible to natural reason (Carroll, 2012).

Problems of Induction

The problem of justifying the inference from the observed to the unobserved; or from particular instances to generalizations; or from the past to the future has been particularly acute for nominalists, who deny the existence of universals. Realists about universals thought they could justify induction. The problem of the rational grounds for induction came into sharp focus in Hume's work. His skepticism about induction is the claim that any attempt to show, based on experience, that a regularity that has held in the past will or must continue to hold in the future will be circular and question-begging. Mill, a radical inductivist, never thought there was a problem of induction. He took it that induction did not need any justification (Huber, 2007). The justification of induction started to become a problem in the late nineteenth and the early twentieth century's. John Venn (1834-1923) took it to be the problem of establishing the foundation of the belief in the uniformity of nature and argued that this belief should be taken as a logical postulate, while the issue of its origin should be relegated to psychology. It was John Maynard Keynes (1883-1946), in his Treatise on Probability (1921), who first interpreted Hume's critique of causation ...