Regularity theory (RT) attempts to account for laws in a descriptive manner contra the necessitarian position (NT), which expresses the laws of nature as nomic necessity. According to the RT the fundamental regularities are brute facts; they neither have nor require an explanation. Regularity theorists attempt to formulate laws and theories in a language where the connectives are all truth functional. Thus, each law is expressed with a universal quantifier as in [(x) (Px ⊃ Qx)]. The NT states that there are metaphysical connections of necessity in the world that ground and explain the most fundamental regularities. Necessitarian theorists usually use the word must to express this connection. Thus, NT maintains must-statements are not adequately captured by is-statements (must ≠ is, or certain facts are unaccounted for).
David Hume was an 18th century skeptic from Scotland who is considered an authority by many philosophers in challenging miracles. Consider his take in An Inquiry Concerning Human Understanding:
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 as can be imagined… It is no miracle that a man, seemingly in good health, should die on a sudden: 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.
Hume’s idea of “extraordinary claims need extraordinary evidence” is pictured in a scale. On one side is full proof and the other side is the evidence from all people in all the ages for the regularity of the laws of nature, which also amounts to full proof. Thus, proof stands against proof and does not incline in either direction, the wise man cannot hold to a miracle with any degree of certainty. According to Hume, miracles are violations of the “laws of nature” that “firm and unalterable” experience has solidly established. Only a superior testimony of experience may override this proposition, but, unfortunately, there cannot be such a testimony, for if there were, miracles would no longer merit their name.
Have you ever heard, “Well, that’s just a theory” or “a theory hasn’t been proven.” You’ll find quite a bit of this in regards to evolution–“Well, evolution is just a theory.” Objecting to a theory because it is ‘just a theory’ is a misunderstanding of what a theory really is. Please take the time to understand what a scientific theory really is.
A theory is distinct from a mere scientific explanation. Scientific explanation requires a causal explanation, which requires a law-governed explanation. Natural law describes but does not explain natural phenomena. Newton’s law of universal gravitation described, but did not explain, what caused gravitational attraction. Theories unify empirical regularities and describe the underling process that account for these phenomena. Within theories are axioms, a small set of postulates, which are not proved in the axiom system but assumed to be true.
A theory goes beyond natural laws and scientific explanations in explaining the scientific explanations. A theory refers to a body of explanatory hypotheses for which there is strong support. Theories are a conjunction of axioms (of the laws of nature) and correspondence of rules specified in a formalized ideal language.