The paper deals with the possibility of a theory of the nature of law as such, a theory which will be necessarily true of all law. It explores the relations between explanations of concepts and of the things they are concepts of, the possibility that the law has essential properties, and the possibility that the law changes its nature over time, and that what is law at a given place and time depends on the culture and concepts of that place (...) and time. It also considers the possibility of understanding the institutions, such as the law, of cultures whose concepts are alien to us. The position advocated offers a reconciliation of ways in which a theory of the nature of law is parochial with its claim to be universal. (shrink)