Every politically organized state has its own law, but in nearly all modern states this law has not been independently developed but is derived from a system that grew up either in the Roman Empire of in England.
The usual way of designating those derived from Rome is to call them “civil law” systems while those derived from England are called “common law” systems. Both these terms, unfortunately, have other meanings as well, and the similarity is a source of frequent confusion.
To civil law and common law as sources of modern legal systems, we must add “canon law,” or the law of the Roman Catholic Church and, to a lesser degree, of the Anglican Church, and the “law merchant,” which, with the medieval maritime law, was formally incorporated in the law of European countries, including England.
Civil and common law have spread beyond Europe and America into Asia and Africa. Here they have met resistance from locally established systems and from non-Christian religions. In some instances, as in India, China, Japan, Turkey, and Egypt, the prevailing law is to a greater or less degree native to the country but has been overlaid with elements – sometimes large groups of elements – derived from the civil or common law.
In other Asiatic and African communities, the native law, especially in Mohammedan countries outside of those mentioned, has been only slightly influenced by Europe. There is a tendency to standardization, however, which gets its impulse from the increasing complexity of international relations, both economic and political.
International law, itself, although professing a supranational foundation, is generally expressed in terms derived from the civil law.
Any particular system of local law can be studied by itself as a matter of history or descriptive sociology, and the elements of which it is composed can be arranged in any order that has logical significance or is specially related to the society which is regulated by the law.
But the law may also be examined as a general science and an attempt may be made to discover principles that apply to law everywhere.
Law examined scientifically is commonly called “jurisprudence” in English-speaking countries, a term that unfortunately, like other legal terms, is used in a wholly different sense in other European languages, where for the most part it is applied to the decisions of courts.
As a science, the law presents more difficulties than other complexes of social relations because of its subject matter, outside of court organization itself and the procedure used by courts is nothing less than the whole range of human life.
We may, however, say of law that it is a value of normative science, that is, that is sets standards of right, wrong, or neutral conduct which courts will accept and which, when accepted, will become judgments that the executive branch of the government will enforce.
The source of these standards may be either legislative command, or custom, or rationalize precedent, or a sense of morals or of equity. The nature of law has often been asserted to lie in commands issued by the sovereign.
In other theories, it is the crystallization of customs and mores, when the crystallization has taken place to the degree that conformity to it will be demanded by a strong public pressure. Still other theories equate the concept of law are therefore properly speaking not law at all.
This was the doctrine of the Stoics and of the older Christian fathers and appears frequently in “natural-law” doctrines.