One of the more important insights in H.L.A.Hart's The Concept ofLaw' comes on the very first pages of the book, where Hart insightfully observes that the typical appeal for a definition of "law" is not really a search for a definition at all, but is instead a mask for any of a number of somewhat different and less definitional questions. We are puzzled about some aspect of law, Hart maintains, such as the relationship between law and morality, or the role of rules in a legal system, or the function of force and coercion in the legal order, but we disguise our specific puzzlements in a quest for a definition.
Hart's admonition about how to understand a request for a definition is sound advice, and it is no less sound because Hart himself turned out in the later chapters of his book to be unfaithful to his initial diagnosis and recommendation. Despite his claims in the first chapter that law might not be susceptible to traditional definition by necessary and sufficient conditions, despite the just-noted view that a request for a definition of law is typically a way of asking a different and more specific question about the character or operation of law, and despite his early explicit denial of the goal of seeking to define law at all, Hart proceeds in much of the balance of his book to offer what looks very much like a definition of law. In particular, he comes close to defining law as the union of primary and secondary rules when combined with the internalization of the ultimate rule of recognition by officials. And although Hart never says precisely that this is a definition of law, many of his followers, critics, and commentators have taken it to be precisely that.