What is it for something to have a nature? And what is it for law to have a nature? Analysis of the concept of law has often been taken to be a search for the essential features of law, but it is not clear that the nature of a phenomenon or artifact is better explained by its essential features than by its common ones. And it is not clear that necessary truths have more explanatory value than typical truths. Especially – but not necessarily – if we recognize the possibility that law is a cluster concept, the value of explaining the widespread but not strictly necessary features of law in explaining law itself becomes more apparent. The jurisprudential project of differentiating law from other social phenomena is an important one, but the distinction may be a fuzzy one and not susceptible either to sharp demarcation or to specification of essential features of law that will assist in differentiation. But if we inquire into what typically or usually or almost always characterizes law rather than what necessarily characterizes it, we may make genuine progress in distinguishing law from the social phenomena to which it is adjacent but with which it is not congruent. This paper, prepared for the McMaster University Conference in May, 2011, on “The Nature of Law: Contemporary Perspectives,” explores these issues.