Dictionary.net

In its most general and comprehensive sense, law signifies a rule of action; and this term is applied indiscriminately to all kinds of action; whether animate or inanimate, rational or irrational. 1 Bl. Com. 38. In its more confined sense, law denotes the rule, not of actions in general, but of human action or conduct. In the civil code of Louisiana, art. 1, it is defined to be "a solemn expression of the legislative will." Vide Toull. Dr. Civ. Fr. tit. prel. s. 1, n. 4; 1 Bouv. Inst. n. 1-3.

Law is generally divided into four principle classes, namely; Natural law, the law of nations, public law, and private or civil law. When considered in relation to its origin, it is statute law or common law. When examined as to its different systems it is divided into civil law, common law, canon law. When applied to objects, it is civil, criminal, or penal. It is also divided into natural law and positive law. Into written law, lex scripta; and unwritten law, lex non scripta. Into law merchant, martial law, municipal law, and foreign law. When considered as to their duration, laws are immutable and arbitrary or positive; when as their effect, they are prospective and retrospective. These will be separately considered.