Common law
The common lawso named because it was "common" to all the king's courts across Englandoriginated in the practices of the courts of the English kings in the centuries following the Norman Conquest in 1066. The British Empire spread the English legal system to its historical colonies, many of which retain the common law system today. These "common law systems" are legal systems that give great precedential weight to common law, and to the style of reasoning inherited from the English legal system.
Common good
Under one name or another, the common good has been a recurring theme throughout the history of political philosophy. As one contemporary scholar observes, Aristotle used the idea of "the common interest" ("to koinei sympheron," in Greek) as the basis for his distinction between "right" constitutions, which are in the common interest, and "wrong" constitutions, which are in the interest of rulers; Saint Thomas Aquinas held "the common good" ("bonum commune," in Latin) to be the end of law and government; John Locke declared that "the peace, safety, and public good of the people" are the ends of political society, and further argued that "the well being of the people shall be the supreme law"; David Hume contended that "social conventions" are adopted and given moral support in virtue of the fact that they serve the "public" or "common" interest; James Madison wrote of the "public," "common," or "general" good as closely tied with justice and declared that justice is the end of government and civil society; and Jean-Jacques Rousseau understood "the common good" ("le bien commun", in French) to be the object of a society's general will and the highest end pursued by government.