For the study of human affairs, there is a strategic question that directs inquiry: why? Why did persons act the way they did? What were their reasons for so acting? When one seeks to study human affairs of a time and place, one puts the question “why?” to the persons of that time and place and seeks to understand their reasons for acting, as they conceive them. But when one seeks to study human affairs generally, one puts the question “why?” to oneself and interrogates what truly good reasons there are for acting. Law earns a place in the study of human affairs only if there are truly good reasons to favor it and, if there are, those reasons will identify the central case of law, which will be united with the law of different times and places by a network of similarities and differences. The argument suggests that there is an order of priority in the questions one asks in order to develop a general theory of law: ask “why choose law?” before and in order to answer “what is law?”