Full Idea
The core of the Dretske-Tooley-Armstrong view of the late 70s is that we have a law of nature when we have a relation of natural necessitation between universals. ..The innovation was that laws are about properties, and only indirectly about particulars.
Gist of Idea
Laws of nature are necessary relations between universal properties, rather than about particulars
Source
Stephen Mumford (Laws in Nature [2004], 06.2)
Book Reference
Mumford,Stephen: 'Laws in Nature' [Routledge 2006], p.85
A Reaction
It sounds as if we should then be able to know the laws of nature a priori, since that was Russell's 1912 definition of a priori knowledge.