the distinction between legal rules and principles -- applied to nature's law

If we trust that there are good reasons for saying that nature is governed by laws of nature even though such a metaphor is anthropomorphic. then it seem only natural to see whether we might extend this metaphor a bit further.  For example, Dworkin spoke of a legal system as consisting not only of rules but of principles, which animate the legal system as a whole and which guide our interpretation in difficult cases.  Anything analogous to that in physics?  Is there something in nature that is more basic than the laws of nature?