Abstract: This chapter concentrates on isolating criteria of adequacy for any philosophical account of what laws of nature are. Sources include David Hume, Charles Sanders Peirce, Hans Reichenbach, Donald Davidson, David Armstrong, and David Lewis. Criteria examined pertain to universality, necessity, intensionality, explanation, prediction, confirmation, counter-factuals, objectivity, and inference to the best explanation. Two main problems are presented: the problem of inference (that it is a law that A should imply that A is the case) and the problem of identification (there should be some identifiable aspect of nature that makes for laws). These two problems together constitute a dilemma, since a solution to one tends to pre-empt any solution to the other.

Keywords: David Armstrong, counter-factuals, Donald Davidson, explanation, David Hume, David Lewis, necessity, Charles Sanders Peirce, Hans Reichenbach, universality,