Constitutional Contract Law

Common law and civil law are the two prominent legal systems in the Western world. This article title seeks an answer to the differences between these two fundamentally different legal theories or systems. In a nutshell, “common law” is the law created by judges on a case by case basis and civil law is the law created by a civil authority to be applied to all cases (such as a statute or constitution). A more detailed explanation follows:


The common law is the body of law that develops over time through the decisions of judges deciding outcomes on a case by case basis, rather than from statutes or constitutions. In this system, past cases and their decisions are relied on to determine what the outcome ought to be in a current case. This application of past decisions to current cases is called precedent.

What is confusing to those in the United States is that this Common Law or “judge-made” law is what develops the civil law of each state. The civil law in this context (as opposed to the Civil Law context intended by the article title), is the law that address disputes between individuals. This is distinct from the body of law called criminal law that addresses the penalties imposed upon citizens for a violation of a governmental rule. Here, civil law, the body of law, as opposed to Civil Law, the system of law, is like the difference between Democrat, the politician, and democratic, the theory. Confusing, but important to differentiate.

So now that you know that when someone talks about “Common Law,” they are referring to the law judges create when they decide a case, and that, in the United States, this type of “judge-made” law makes up the bulk of our civil law , which is one of two major types of law in the U.S. (the other being criminal law). You also know that when we talk about “Civil Law” in the next section, we are not discussing the civil law of the U.S.


Civil Law or Roman Law is second prominent legal system in the Western World that is derived from the Roman Empire. The Civil Law system described a system whereby the law of the land derives from the civil authority or the state. Typically, this was written law that did not relate to any particular present controversy or dispute, but was intended to anticipate future disputes and guide behavior to avoid them, or, when that guidance failed, to set forth the penalties or redress that would be available for the failure to so abide. The Civil Law system is still the foundational system in many parts of the world, including continental Europe and Latin America.


The legal system in the United States is said to be a common-law system, based upon the system of England from which the United States borrowed heavily upon its establishment. In fact, the U.S. is a hybrid, heavily incorporating the common law system in it’s civil law and building it’s criminal and administrative law systems on a civil law (or statute) driven model. Underpinning both the civil and criminal law systems is the reliance on precedents and adhering to the decisions of judges and their interpretations of statutes made in previous cases. Forty-nine U.S. states adopt a common law approach with one state, Louisiana, using a civil law system.