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Laws are part of legal systems; a particular law is a law only if it is part of American law or French law or some other legal system. Legal philosophers have persistently attempted to explain why we think of laws as forming legal systems, to evaluate the merits of this way of thinking about the law and to make it more precise by explicating the features that account for the unity of legal systems. Various theories have been suggested but none has been accepted as completely satisfactory, and the continuing debate owes much to the intricacy of the problems involved. This intricacy is also due to a considerable cloudiness in the understanding of the problems themselves. I will attempt, through this Article, to clarify the nature of the problem of the unity of municipal legal systems. My primary aim is not to answer all the relevant questions, but rather to formulate them more precisely, for I believe that in philosophy a clear conception of a problem is half the way to its solution.

The term "a legal system" is not a technical legal term. It may occasionally figure in courts' decisions, but any term can appear there. Although it is occasionally used in legal argument, it has not the character of a technical legal term such as "floating charge" or "fee simpl' or "consideration." Nor is the concept important to the day-today administration of law, as are the concepts of contract, ownership, right, duty, and the like. The term is primarily used in thinking about the law, not in the actual use and application of the law. It is commonly used in books of jurisprudence or comparative law, not in books about property law, torts, or copyright.

Therefore, when trying to clarify the notion of a legal system, the legal theorist does not aim at defining clearly the sense in which the term is employed by legislators, judges, or lawyers. He is, rather, attempting to forge a useful conceptual tool, one which will help him to a better understanding of the nature of law. This does not mean that he should not try to model the concept in a way that would be useful to the solution of certain legal probems. Rather, it means only that even if he does this, he will not be trying to elucidate the meaning of a technical legal term, but instead to provide the legal practitioner with a concept that may help him in tackling some nagging legal problems. But should it really be the goal of the legal theorist to help solve legal problems by molding a precise concept of the identity of a legal system? To what kind of legal problems may such a concept be relevant? And if this is not his goal, what is? Providing an answer to these questions is the main purpose of this Article.

To try to answer these questions we should first distinguish between two possible concepts of the unity of a legal system, which I will call the material unity and the formal unity. The material unity of a legal system consists in its distinctive characteristics; it depends on the content of its laws and on the manner in which they are applied. When trying to explain the characteristic features of a legal system we are not, of course, looking for the detailed regulation of every legal institution. Rather, we are looking for the all-pervasive principles and the traditional institutional structure and practices that permeate the system and lend to it its distinctive character. To distinguish the problem of formal unity from that of material unity, I shall call the former the problem of the identity of legal systems.


Law | Law and Philosophy