Best quote I've seen today:
Law and commerce were indelibly linked in the thought of David Hume, who argued that it is commerce itself that gives rise to notions of justice between people and peoples. Although commerce is today typically seen as something which is proactively enabled by law, it is much more accurate historically to see law as something which emerges because of its vital importance in commerce – and particularly commerce involving foreigners. Within the Roman Empire, it was the ius gentium, the “law of nations,” derived from custom rather than legislation, and applying specifically to noncitizens, that governed most types of commercial transactions.
The modern notion that law is inseparable from the will of a ruler or ruling body, antithetical to the idea of a universal natural law or a ius gentium, has, in parts of the world and during epochs where it has actually been applied, been devastating to economic development.
--Benn Steil and Manuel Hinds, Money Markets, and Sovereignty
Hat tip: Don Boudreaux, Cafe Hayek