What is Law?

Legal Definition
Law is a system of rules that are enforced through social institutions to govern behavior. Laws can be made by a collective legislature or by a single legislator, resulting in statutes, by the executive through decrees and regulations, or by judges through binding precedent, normally in common law jurisdictions. Private individuals can create legally binding contracts, including arbitration agreements that may elect to accept alternative arbitration to the normal court process. The formation of laws themselves may be influenced by a constitution, written or tacit, and the rights encoded therein. The law shapes politics, economics, history and society in various ways and serves as a mediator of relations between people.

A general distinction can be made between (a) civil law jurisdictions (including Catholic canon law and socialist law), in which the legislature or other central body codifies and consolidates their laws, and (b) common law systems, where judge-made precedent is accepted as binding law. Historically, religious laws played a significant role even in settling of secular matters, which is still the case in some religious communities, particularly Jewish, and some countries, particularly Islamic. Islamic Sharia law is the world's most widely used religious law.

The adjudication of the law is generally divided into two main areas referred to as (i) Criminal law and (ii) Civil law. Criminal law deals with conduct that is considered harmful to social order and in which the guilty party may be imprisoned or fined. Civil law (not to be confused with civil law jurisdictions above) deals with the resolution of lawsuits (disputes) between individuals or organizations.

Law provides a rich source of scholarly inquiry into legal history, philosophy, economic analysis and sociology. Law also raises important and complex issues concerning equality, fairness, and justice. There is an old saying that 'all are equal before the law', although Jonathan Swift argued that 'Laws are like cobwebs, which may catch small flies, but let wasps and hornets break through.' In 1894, the author Anatole France said sarcastically, "In its majestic equality, the law forbids rich and poor alike to sleep under bridges, beg in the streets, and steal loaves of bread." Writing in 350 BC, the Greek philosopher Aristotle declared, "The rule of law is better than the rule of any individual." Mikhail Bakunin said: "All law has for its object to confirm and exalt into a system the exploitation of the workers by a ruling class". Cicero said "more law, less justice". Marxist doctrine asserts that law will not be required once the state has withered away. Regardless of one's view of the law, it remains today a completely central institution.
-- Wikipedia
Legal Definition
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.

2. 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.
-- Bouviers Law Dictionary
Legal Definition
1. That which is laid down, ordained or established. A rule or method according to which phenomena or actions coexist or follow each other.

2. A system of principles and rules of human conduct, being the aggregate of those commandments and principles which are either prescribed or recognized by the governing power in an organized jural society as its will in relation to the conduct of the members of such society, and which it undertakes to maintain and sanction and to use as the criteria of the actions of such members. "Law" is a solemn expression of legislative will. It outers and permits and forbids. It announces rewards and punishments. Its provisions generally relate not to solitary or singular cases, but to what passes in the ordinary course of affairs. Civ. Co.de La. arts. 1.

2. "Law," without an article, properly implies a science or system of principles or rales of human conduct, answering to the Latin "jus;" as when it is spoken of as a subject of sindy or practice. In this sense, it includes the decisions of courts of justice, as well as acts of the legislature. The judgment of a competent court, until reversed or otherwise superseded, la law, as much as any statute. Indeed, it may happen that a statute may be passed in violation of late, that is, of the fundamental law or constitution of a state; that it is the prerogative of courts in such cases 'bo declare it void, or, in other words, to declare it not to be law. Burrill.

3. A rule of civil conduct prescribed by the supreme power in a state. 1 Steph. Comm. 25; Civ. Code Dak. § 2; Pol. Code Cal. § 4466. A "law," in the proper sense of the term, is a general rule of human action, taking cognizance only of external acts, enforced by a determinate authority, which authority is human, and among human authorities is that which is paramount in a political society. Holl. Jur. 36. A "law," properly so called, is a command which obliges a person or persons ; and, as distinguished from a particular or occasional command, obliges generally to acts or forbearances of a class. Aust. Jur. A rule or enactment promulgated by the legislative authority of a state; a long-established local custom which has the force of such an enactment. Dubois v. Hepburn, 10 Pet. 18, 9 In Ed. 325.

4. In another sense the word signifies an enactment; a distinct and complete act of positive law; a statute, as opposed to rules of civil conduct deduced from the customs of the people or judicial precedents. When the term "law" is used to denote enactments of the legislative power, it is frequently confined, especially by English writers, to permanent rules of civil conduct, as distinguished from other acts, such as a divorce act, an appropriation bili, an estates act. Rep. Eng. St. h. Com. Mar. 1856. For other definitions and descriptions, see State v. McCann, 4 Lea (Tenn.) 9; State v. Hockett, 70 Iowa, 454, 30 N. W. 744; Duncan v. Magette, 25 Tex. 253; Baldwin v. Philadelphia, 99 Pa. 170; State v. Fry, 4 Mo. 189; Forepaugh v. Railroad Co., 128 Pa. 217, 18 Atl. 503, 5 L. R. A. 508, 15 Am. St. Rep. 672 ; State v. Swan, 1 N. D. 5, 44 N. W. 492; Smith v. U. S-, 22 Fed. Cas. 696; Swift v, Tyson, 16 Pet 1, 10 Lu Ed. 865; Miller v. Dunn, 72 Cal. 462, 14 Pac. 27, 1 Am. St. Rep. 67; Bier v. McGehee, 148 U. S. 137, 13 Sup. Ch 580, 37 In Ed. 307. Historically considered. With reference to its origin, "law" is derived either from judicial precedents, from legislation, or from custom. That part of the law which is derived from judicial precedents is called "common law," "equity," or "admiralty," "probate," or "ecclesiastical law," according to the nature of the courts by which it was originally enforced. (See the respective titles.) That part of the law which is derived from legislation is called the "statute law." Many statutes are classed under one of the divisions above mentioned because they have merely modified or extended portions of it, whlle others have created altogether new rules. That part of the law which is derived from custom is sometimes called the "customary law," as to which, see Custom. Sweet. The earliest notion of law was not an enumeration of a principle, but a judgment in a particular case. When pronounced in the early ages, by a king, it was assumed to be the result of direct divine inspiration. Afterwanis came the notion of a custom which a judgment affirms, or punishes its breach. In the outset, however, the only authoritative statement of right and wrong is a judicial sentence rendered after the fact has occurred. It does not presuppose a law to have been violated, but is enacted for the first time by a higher form into the judge's mind at the moment of adjudication. Maine, Anc. Law, (Dwight's Ed.) pp. xv.

5. Synonyms and distinctions. According to the usage in the United States, the name "constitution" is commonly given to the organic or fundamental law of a state, and the term "law" is used in contradistinction to the former, to denote a statute or enactment of the legislative body. "Law," as distinguished from "equity," denotes the doctrine and procedure of the common law of England and America, from which equity is a departure. The term is also used in opposition to "fact." Thus questions of law are to be decided by the court, while it Is the province of the jury to solve questions of fact. Classification. With reference to its subject-matter, law is either public or private. Public law ls that part of the law which dcals with the state, either by itself or in its relations with individuals, and ls divided into

(1) constitutional law;

(2) administrative law;

(3) criminal law;

(4) criminal procedure;

(5) the law of the state considered in its quasi private personality;

(6) the procedure relating to the state as so considered. Holl. Jur. 300. Law is also divided into substantive and adjective. Substantive law is that part of the law which creates rights and obligations, while adjective law provides a method of enforcing and protecting them. In other words, adjective law is the law of procedure. Holl. Jur. 61, 238. The ordinary, but not very useful, division of law into written and unwritten rests on the same principle. The written law is the statute law; the unwritten law is the common law, (q. v.) 1 Steph. Comm. 40, following Blaekstone. Kinds of statutes. Statutes are called "general" or "public" when they affect the community at large; and local or special when their operation is confined to a limited region, or particular class or interest. Statutes are also either prospective or retrospective; the former, when they are intended to operate upon future cases only; the latter, when they may also embrace transactions occurring before their passage. Statutes are called "enabling" when they confer new powers; "remedial" when their effect is to provide relief or reform abuses; "penal" when they impose punishment, pecuniary or corporal, for a violation of their provisions.

5. In old English jurisprudence, "law" is used to signlfy an oath, or the privilege of being sworn; as in the phrases "to wage one's law," "to lose one's law."
See also
-- Black's Law Dictionary
Legal Definition
A statute; a bill; a legislative enactment; the whole body or system of rules of conduct, including both decisions of courts and legislative acts. See 72 Cal. 462, 1 Am. St. Rep. 67, 14 Pac. 27.
-- Ballentine's Law Dictionary