Legal pluralism originated in the differentiation of the ecclesiastical polity from secular polities. The church declared its freedom from secular control, its exclusive jurisdiction in some matters, and its concurrent jurisdiction in other matters. Laymen, though governed generally by secular law, were subject to ecclesiastical law, and to the jurisdiction of ecclesiastical courts, in matters of marriage and family relations, inheritance, spiritual crimes, contract relations where faith was pledged, and a number of other matters as well.
Conversely, the clergy, though governed generally by canon law, were subject to secular law, and to the jurisdiction of secular courts, with respect to certain types of crimes, certain types of property disputes, and the like. Secular law itself was divided into various competing types, including royal law, feudal law, manorial law, urban law, and mercantile law. The same person might be subject to the ecclesiastical courts in one type of case, the king’s court in another, his lord’s court in a third, the manorial court in a fourth, a town court in a fifth, a merchants’ court in a sixth.
The very complexity of a common legal order containing diverse legal systems contributed to legal sophistication. Which court has jurisdiction? Which law is applicable? How are legal differences to be reconciled? Behind the technical questions lay important political and economic considerations: church versus crown, crown versus town, town versus lord, lord versus merchant, and so on. Law was a way of resolving the political and economic conflicts. Yet law could also serve to exacerbate them.
The pluralism of Western law, which has both reflected and reinforced the pluralism of Western political and economic life, has been, or once was, a source of development, or growth legal growth as well as political and economic growth. It also has been, or once was, a source of freedom. A serf might run to the town court for protection against his master. A vassal might run to the king’s court for protection against his lord. A cleric might run to the ecclesiastical court for protection against the king.
There is a tension between the ideals and realities, between the dynamic qualities and the stability, between the transcendence and the immanence of the Western legal tradition. This tension has periodically led to the violent overthrow of legal systems by revolution. Nevertheless, the legal tradition, which is something bigger than any of the legal systems that comprise it, survived and, indeed, was renewed by such revolutions.
Law and Revolution, The Formation of the Western Legal Tradition.
Harold J. Berman (1983)