The UK, Finland and New Zealand assert the ideal of parliamentary sovereignty, whereby the unelected judiciary may not overturn law passed by a democratic legislature. The third type of legal system—accepted by some countries without separation of church and state—is religious law, based on scriptures. The specific system that a country is ruled by is often determined by its history, connections with other countries, or its adherence to international standards. The sources that jurisdictions adopt as authoritatively binding are the defining features of any legal system. Yet classification is a matter of form rather than substance since similar rules often prevail. The Old Testament dates back to 1280 BC and takes the form of moral imperatives as recommendations for a good society.
- Constitution, U.S. laws, rules or regulations, or a treaty signed by the U.S., and the federal courts have exclusive jurisdiction, then the case must be litigated in federal