Examples include the Jewish Halakha and Islamic Sharia—both of which translate as the “path to follow”—while Christian canon law also survives in some church communities. Often the implication of religion for law is unalterability, because the word of God cannot be amended or legislated against by judges or governments. However, a thorough and detailed legal system generally requires human elaboration.

In general, legal systems can be split between civil law and common law systems. The term “civil law”, referring to the civilian legal system originating in continental Europe, should not be confused with “civil law” in the sense of the …