Add to ORKGRun Lewisian best system competitions as usual but organise separate competitions for each special science: one compe- tition for chemistry, one for biology, etc. depending on how far up you are willing to go. In order to do so, at least one hurdle has to be taken: Lewis’s theory does not straightforwardly allow for laws with exceptions. Yet, especially the laws of non-fundamental laws like, say, chemistry or biology are said to be ceteris paribus laws, i.e., laws that are haunted by exceptions and therefore in need of proviso clauses