Laws of nature
1. The task of the theoretical scientist is to set forth the laws of nature. In any field he will have a number of observational results. He seeks the most natural generalisation or extrapolation of those results, or, as I shall put it, the simplest formula from which past results can be deduced.
Sometimes the scientist will be able to see no simple formula, that is formula of sufficient simplicity, compatible with a collection of data in some field, and in that case will not feel justified in adopting any one formula and making predictions on the basis of it. This means that laws of nature do not just describe what happens. They describe what happens in a regular and predictable way. When what happens is entirely irregular and unpredictable, its occurrence is not something describable by natural laws.
Given this understanding of a law of nature, what is meant by a violation of a law of nature? Hume seems to mean an occurrence of a non-repeatable counter-instance to a law of nature. This assumes that the operation of a law of nature is logically compatible with the occurrence of an exception to its operation. However, some may argue that a universal law has the form “so-and-sos always do such- and- such” which seems incompatible with a counter-instance reported by “this is a so-and-so and did not do such-and-such.” It is argued that both statements cannot be true together and so the law is wrong. However, if it could also be the case that if we left the law unmodified, we have good reason to believe it would give correct predictions in all other conceivable circumstances, then it seems valid to claim that there is a law of nature and in this one instance it has been violated. Hence the idea of a law on nature being violated is coherent.
(adapted from The Concept of Miracle by Swinburne)
2. Alastair McKinnon argues that laws of nature do not in any way constrain the course of nature. They exert no opposition or resistance to anything, not even to the odd or exceptional. They are simply highly generalised shorthand descriptions of how things do in fact happen. Hence there can be no suspensions of natural law rightly understood. It would be better to replace the phrase “natural law” with “the actual course of events”. In this understanding, nothing in the definition of natural law would exclude such events as the resurrection of Jesus. Hence, to define miracles as a violation of a law of nature is a contradiction in terms.
In this view, no question of miracles can therefore arise. Whatever happens must be included in his understanding of natural laws. Since miracles are unique events, not necessarily repeatable in the same circumstances, a “natural law” about human death would have to take the form “when human beings are dead, they stay dead, except Jesus, Lazarus, the son of the widow of Nain etc”.
(adapted from In Defence of Miracles edited by Geivett and Habermas)
3. A miracle is a violation of the laws of nature; and as a firm and unalterable experience has established these laws, the proof against a miracle, from the very nature of the fact, is as entire as any argument from experience can possibly be imagined. Nothing is esteemed a miracle, if it ever happens in the common course of nature. It is no miracle that a man, seemingly in good health, should die suddenly: because such a kind of death, though more unusual than any other has yet been frequently observed to happen. But it is a miracle that a dead man should come to life; because that has never been observed in any age or country. There must, therefore, be a uniform experience against every miraculous event, otherwise the event would not merit that appellation. And as a uniform experience amounts to a proof, there is here a direct and full proof, from the nature of the fact, against the existence of any miracle…
….the knavery and folly of men are such common phenomena, that I should rather believe the most extraordinary events arise from their concurrence, than to admit of so signal a violation of the laws of nature.
(On Miracles by Hume)