Universality is not sufficient to distinguish laws of nature from accidental regularities. A multitude of additional defining features have been suggested. Yet, once it is acknowledged that exceptionless universality is not the only criterion for lawhood it is possible to start questioning whether it is necessary.
Markus Schrenk's The Metaphysics of Ceteris Paribus Laws takes this bold step and it's provocative conclusion is that existing theories - especially David Lewis's and David Armstrong's - are, in fact, strong enough to guarantee lawhood even if there are instances that do...