It is often contended that the special sciences, and even fundamental physics, make use of ceteris-paribus law-statements. Yet there are general concerns that such law-statements are vacuous or untestable or unscientific. I consider two main kinds of ceteris-paribus law-statement. I argue that neither kind is vacuous, that one of the kinds is untestable, that both kinds may count as scientific to the extent that they form parts of conjunctions that imply novel falsifiable statements which survive testing, but that one kind (...) has an affinity with ad hoc manoeuvres that are unsatisfactory from a scientific point of view. I show that the contemporary debate about ceteris-paribus law-statements is afflicted with error and confusion because of a general failure to disentangle the notions: non-vacuous, testable, scientific, verifiable, falsifiable, and ad hoc. (shrink)