One reason to posit governing laws is to explain the uniformity of nature. Explanatory power can be purchased by accepting new primitives, and scientists invoke laws in their explanations without providing any supporting metaphysics. For these reasons, one might suspect that we can treat laws as wholly unanalyzable primitives. (John Carroll’s *Laws of Nature* (1994) and Tim Maudlin’s *The Metaphysics Within Physics* (2007) offer recent defenses of primitivism about laws.) Whatever defects primitive laws might have, explanatory weakness should not be (...) one of them. However, in this essay I’ll argue that wholly primitive laws cannot explain the uniformity of nature. The basic argument is based on the following idea: though a primitive law that P makes P likely, the primitive status of the law provides no reason to think that P must describe (or otherwise give rise to) a natural regularity. After identifying the problem for primitive laws, I consider an extension of the objection to all theories of governing laws and suggest that it may be avoided by a version of the Dretske/Tooley/Armstrong theory according to which laws are relations between universals. (shrink)