List of national legal systems
Common law is currently in practice in Ireland, most of the United Kingdom (England and Wales and Northern Ireland), Australia, New Zealand, Bangladesh, India (excluding Goa), Pakistan, South Africa, Canada (excluding Quebec), Hong Kong, the United States (on a state level excluding Louisiana), and many other places. In addition to these countries, several others have adapted the common law system into a mixed system. For example, Nigeria operates largely on a common law system, but incorporates religious law.
Common law
Well into the 19th century, ancient maxims played a large role in common law adjudication. Many of these maxims had originated in Roman Law, migrated to England before the introduction of Christianity to the British Isles, and were typically stated in Latin even in English decisions. Many examples are familiar in everyday speech even today, "One cannot be a judge in one's own cause" (see Dr. Bonham's Case), rights are reciprocal to obligations, and the like. Judicial decisions and treatises of the 17th and 18th centuries, such at those of Lord Chief Justice Edward Coke, presented the common law as a collection of such maxims.