The common law is a body of laws and authorities among the judicial branch that was kind of a common heirloom that the people of America brought with them when they began to set up their colonial governments. And, of course, aspects of the common law then informed so many aspects of the daily lives of the colonists, from tort, to contract, to property, to real estate, to ordinary criminal law, protections of defendants who are faced with accusations of crime. A large body of judge-made law that came from England. Now under the common law, even if these rules and regulations were developed by the courts, they were always subject to change or abrogation, or modification by Parliament itself. Parliament always had ultimate control over the common law because Parliament, of course, represented the will of the people themselves. Rules, then, that developed under common law, reflected the idea that the government, when it sits, reflects and sits as the people themselves. These common law rules that show so much deference to Parliament, and rules that, of course, included sedition, and the right to punish people for criticizing, or interfering with, the operations of government. The reason why those rules were there is, of course, government ... in a parliamentary system ... represented the people themselves. So to criticize the Crown, or to criticize the government, you were actually criticizing the people of England. That wasn't the way rules and ideas developed under the American system. Under the American system, the people represented their will not through the operations of government, but through a written constitution. The people stood apart and stood as judges over their government. That meant there had to be new rules when it came to laws regarding defamation, and sedition, and freedom of speech. Common law rules and methodologies that might be appropriate in a parliamentary system were not clearly at all going to map onto what was happening under the American system.