John Austin’s utilitarian answer was that law is “commands, backed by threat of sanctions, from a sovereign, to whom people have a habit of obedience”. Natural lawyers on the other side, such as Jean-Jacques Rousseau, argue that law reflects essentially moral and unchangeable laws of nature. The concept of “natural law” emerged in ancient Greek philosophy concurrently and in connection with the notion of justice, and re-entered the mainstream of Western culture through the writings of Thomas Aquinas, notably his Treatise on Law.
As nationalism grew in the 18th and 19th centuries, the Law Merchant was incorporated into countries’ local law under new civil codes. In contrast to English common law, which consists of enormous tomes of case law, codes in small books are easy to export and easy for judges to apply. EU law is codified in treaties, but develops through de facto precedent laid down by the European …