Law can be defined broadly as a system of standards and rules of civil society: standards of human conduct that impose obligations and grant corresponding rights, and institutional rules regarding the ascertainment, creation, modification, and enforcement of these standards. The question "What is law?" has elicited a myriad of answers throughout human history, ranging from the Old Testament's assertion of law as the will of God to the thesis of Karl \TMarx\t and Friedrich \TEngels\t that law is an expression of class ideology. CONCEPTIONS OF LAW Notwithstanding the marked historical diversity in conceptions of law, many if not most of the conceptions of law can be placed in one of six broad categories: natural law, legal positivism, historical jurisprudence, sociological jurisprudence, Marxism, and legal realism. Like Western philosophy in general, philosophy of law in particular first emerged in ancient Greece. In the 5th century BC the \TSophists\t and \TSocrates\t, along with his followers, took up the question of the nature of law. Both recognized a distinction between things that exist by nature (physis) and those that exist by human-made convention (nomos). The Sophists, however, tended to place law in the latter category, whereas Socrates put it in the former, as did \TPlato\t and \TAristotle\t. Thus began the debate that continues even today over whether the essence of law is nature and reason on the one hand or convention and will on the other hand. Thinkers who believe the former belong to what can be loosely called the tradition of \Tnatural law\t, and those who assert the latter belong to the tradition of legal positivism. Natural Law and Legal Positivism All of the early political philosophers were deeply concerned with the nature of justice and good government. The idea of natural law can be found in Plato's concept of the just state--governed by the good and the wise--which in his view reflects the naturally hierarchical structure of human society. Governed by wisdom, the ideal state has no need of conventional law because wisdom itself is the recognition of the primacy of natural order. Aristotle made a distinction, however, between paramount natural law that establishes general precepts and human-made law that merely imposes sanctions for violations of those precepts. Marcus Tullius \TCicero\t, a Roman statesman and politician who was also a Stoic (see \TStoicism\t) legal philosopher, put forward the first full-blown theory of natural law, in his Commonwealth (51 BC): "True law is right reason in accord with nature; it is of universal application, unchanging and everlasting...." Later, Saint \TAugustine\t combined Stoic legal thinking with Christian philosophy by identifying eternal, divine law with God's reason and will and by considering human law as being derived from and limited by divine law. The natural-law tradition culminated in the theory of Saint Thomas \TAquinas\t, which synthesized Aristotelian, Stoic, \TRoman law\t, and Christian elements. Aquinas formulated a fourfold classification of types of law: (1) eternal law--God's plan for the universe; (2) natural law--that part of the eternal law in which humans participate by their reason; (3) divine law--God's direct revelation to humankind through the scriptures; and (4) human law--particular determinations of certain matters arrived at through the use of reason from the general precepts of the natural law. Aquinas also argued--as Cicero had done--that an unjust law was not a genuine law but rather an act of violence. Later thinkers who may be placed in the natural-law tradition include Hugo \TGrotius\t, Thomas \THooker\t, Gottfried \TLeibniz\t, Baruch \TSpinoza\t, Jean Jacques \TRousseau\t, and Jacques \TMaritain\t. In marked contrast to natural-law jurists, legal positivists such as Thomas \THobbes\t argued that the essence of law is the command or will of the sovereign and that an "unjust law" is a contradiction in terms because the existing law is itself the standard of justice. Jean \TBodin\t had anticipated Hobbes in the former respect when he claimed that "law is nothing else than the command of the sovereign in his exercise of sovereign power." Bodin had added, however, that the prince "has no power to exceed the law of nature," and he expected natural law to be found in constitutional restraints. Thus Bodin had not broken unequivocally from the natural-law tradition. John \TLocke\t's criticism of Hobbesian theory set the stage for modern theories of \Tcivil disobedience\t and for independent government in the American colonies. Many legal positivists after Hobbes have backed down from his extreme claims. For example, Jeremy \TBentham\t and John \TAustin\t agreed that law was the command of the sovereign but rejected the idea that law was necessarily the standard of justice or morality. Bentham was more interested in the law's utility in providing the greatest happiness for the greatest number. Hans Kelsen (1881-1973) and the English legal philosopher H. L. A. Hart repudiated the command theory of law, arguing respectively that laws are essentially derived from norms for the creation of law and rules that arise from society. Nonetheless the central point of contention between natural-law jurists and legal positivists remains the same: the former insist on a necessary connection between legal validity and moral value, whereas the latter hold that no such connection is necessary. As Hart put it in The Concept of Law (1961), natural law jurists hold that "there are certain principles of human conduct, awaiting discovery by human reason, with which man-made law must conform if it is to be valid," whereas legal positivists contend that "it is in no sense a necessary truth that laws reproduce or satisfy certain demands of morality though in fact they have often done so." Historical Jurisprudence In contrast with both natural-law jurists and legal positivists, members of the historical school of jurisprudence, most notably Friedrich Karl von \TSavigny\t, maintained that "an organic connection {exists} between law and the nature and character of a people." In his view legislation is relatively unimportant except insofar as it declares customary law, which is the truly living law. Thus the spirit of the people and not the commands of the sovereign or right reason in accord with nature constitutes the essence of law. Other important juridical historians include Otto Friedrich von \TGierke\t, Sir Henry \TMaine\t, and Frederick William \TMaitland\t. \TMontesquieu\t may also be placed in this school, although he preceded it in time. Sociological Jurisprudence Akin to historical jurisprudence is sociological jurisprudence, which can be traced to the writings of Rudolf von Jhering (1818-92). He rejected Savigny's theory on the ground that the latter, in viewing law as a spontaneous expression of subconscious forces, overlooked the importance of conscious human purposes and the pursuit of interests embodied in the law. Jhering also emphasized that law must be understood in the context of social life. He thus foreshadowed the jurisprudence-of-interests school of thought and sociological jurisprudence. Both strains of Jhering's thought influenced the jurisprudential theory of Roscoe \Tpound\t and other American sociological jurists, who focused on the notion of "social engineering" law as a means of social control and the relationship between law and society. Marxism In contrast to historical and sociological jurists, Marxist jurists stress the relationship between law and the economic aspects of society rather than society generally and emphasize the pursuit of class interests instead of interests generally. Responding to critics, Marx and Engels wrote in The Communist Manifesto (1848): "Your law is but the will of your class exalted into statutes, a will which acquires its content from the material conditions of {the} existence of your class." Important Marxists who have refined the theory of law put forward by Marx and Engels include Andrei \TVyshinsky\t, E. Pashukanis (1891-1938), and Karl Renner (1870-1950). Legal Realism Legal realism, which has flourished in America, has been more of a movement than a school of thought. Its fundamental tenets were anticipated by Justice Oliver Wendell \THolmes\t, Jr., in the following remarks: "the life of the law has not been logic; it has been experience" and "prophecies of what courts will do in fact, and nothing more pretentious, are what I mean by law." Like sociological jurists, legal realists revolted against analytic jurisprudence and formalism, or mechanical jurisprudence, but the realists were somewhat more extreme than the sociological jurists in their claims. They even went so far as to claim that legal rules are myths and that laws are really nothing more than particular judicial decisions. Realists combined behaviorism with this nominalism and thus aspired to the scientific study of law. The most influential of American legal realists include Karl Llewellyn (1893-1962), Jerome Frank (1889-1957), and Thurman Arnold (1891-1969). The most outspoken of its critics include Lon Fuller (b.1902), H. L.A. Hart, and Ronald Dworkin (b.1931). Types of Law Traditionally, law has been divided into public law and private law. Public and private laws that set forth the substance of rights and obligations are sometimes called substantive law in order to distinguish them from \Tlegal procedure\t; the latter specifies the methods to be followed in adjudicating substantive law cases in order to ensure they are conducted in a manner protective of the rights of the participants. If procedural law relates to how the rights and duties of substantive law are to be vindicated and enforced, substantive law pertains to what the law is on a given matter. Public Law Public law concerns the structures, powers, and operations of a government, the rights and duties of citizens in relation to the government, and the relationships among nations. It can be divided further into constitutional law, \Tadministrative law\t, \Tcriminal\t \Tlaw\t, and \Tinternational law\t. Constitutional law, the fundamental or paramount law of a nation, is derived from the nation's \TConstitution\t, which comprehends the body of rules in accordance with which the powers of government are exercised. Constitutions may be either written or unwritten--America's is an example of the former, England's of the latter. In some nations, courts have the power of \Tjudicial review\t, whereby they declare unconstitutional and therefore void laws that contravene the provisions or arrangements of the constitution. Administrative law includes laws governing the organization and operation of agencies of the executive branch of government, the substantive and procedural rules that these agencies formulate and apply pursuant to their regulatory and other administrative functions, and \Tcourt\t decisions involving public agencies and private citizens. Criminal law consists of laws that impose obligations to do or forbear from doing certain things, the infraction of which is considered to be an offense not merely against the immediate victim but also against society. Most such laws are backed up by sanctions or punishments, which are applied in the event of conviction. Major breaches of the criminal law, usually defined as those punishable by imprisonment for more than 1 year, are termed \Lfelon\lies. Less serious crimes, called \Lmisdemeanor\ls, are punishable by imprisonment for a shorter period or by fines or both. Finally, international law concerns the relationships among nations, including the use of the high seas, \Tinternational trade\t, boundary disputes, warfare methods, and the like. Some legal theorists question whether international law is genuine law because it lacks an international legislature, centrally organized sanctions, and courts with involuntary jurisdiction, all of which characterize national legal systems. Private Law Unlike public law, private law does not involve government directly but rather indirectly as an adjudicator between disputing parties. Private law provides rules to be applied when one person claims that another has injured his or her person, property, or reputation or has failed to carry out a valid legal obligation. Private law also includes laws that confer powers or capabilities to create structures of obligations and rights on individuals who wish to achieve given legal objectives. On the basis of the types of legal rights and obligations involved, private law is conventionally subdivided into six main categories: (1) \Ttort\t law; (2) \Tproperty\t law; (3) \Tcontract\t and \Tbusiness law\t; (4) \Tcorporation\t law; (5) inheritance law (see \Twill\t, law); and (6) family law. Sources of Law Laws can also be subdivided on the basis of the sources of law from which they derive. The various legal systems of the world recognize as valid and therefore binding on their subjects some or all of the following major sources: constitutions and administrative rules, such as those described above; legislative statutes; judicial precedents; and customary practice. Although when a person thinks of law, the concept of statutes comes most readily to mind, statutes are now outnumbered by the innumerable administrative rules and regulations that have accompanied the growth of administrative government in modern times. Judicial precedents (also known as case law), which are recognized as valid law that later courts must follow in \Tcommon law\t but not in \Tcivil law\t systems, are prior cases decided by courts. Finally, customary practice is a minor source of law in the legal systems of advanced industrial nations, but it is the primary if not the only source in primitive legal systems and is inextricably linked with kinship, taboo, religion, and traditional authority systems. LAWYERS The requirements for becoming a lawyer in the United States are set by each state and the District of Columbia. In general, an individual must earn a bachelor's degree and then attend a recognized law school for either 3 years as a full-time day student or 4 years as a part-time evening student. Law schools grant the juris doctor (J.D.) degree, and many also offer a master of laws (LL.M.) program. Some also offer a doctoral program leading to the degree of doctor of the science of jurisprudence (J.S.D.). The basic J.D. degree is sufficient for either law practice, law teaching, or the judiciary. In order to become an \Tattorney\t the individual must also pass the state's bar examination. A person who wishes to work in the law but does not wish to pursue the program leading to a law degree may train to be a paralegal assistant to lawyers (see \Tparalegal services\t). Various schools have been set up in recent years to train such persons. Most lawyers are in private practice. In larger centers of population they tend to form partnerships that may range from two to hundreds of members. Because the law touches on all aspects of life, the work of lawyers is of infinite variety. Most lawyers specialize in a field such as tax law, estate planning, corporate law, workers compensation law, and so forth. Some lawyers specialize in trial work. Many work for federal, state, or local government or for administrative agencies. Some lawyers are employed by business firms; the legal department of a large corporation or bank may include dozens of lawyers. In England legal representation is divided between solicitors, or attorneys, and barristers. A client goes to a solicitor, who drafts legal documents, advises, and handles matters that can be settled out of court or in lower courts. If a case must go to a higher court the solicitor employs a barrister, who is permitted to plead in superior courts. In these cases the solicitor and barrister form a legal team. Reviewed by Nicholas D. Constan, Jr. Bibliography: Abraham, Henry J., The Judicial Process, 3d rev. ed. (1975); Berman, Harold J., Justice in the \TUSSR\t, rev. ed. (1963); Black, Donald, The Behavior of Law (1976); Bodenheimer, Edgar, Jurisprudence (1974); Cataldo, Bernard F., et al., Introduction to Law and the Legal Process, 2d ed. (1973); Corley, Robert N., The Legal Environment of Business, 4th ed. (1977); Frank, Jerome, Law and the Modern Mind (1930; repr. 1949); Freund, Paul A., On Law and Justice (1968); Friedrich, Carl, The Philosophy of Law in Historical Perspective, 2d ed. (1963); Hart, Herbert L. A., The Concept of Law (1961); Hoebel, Edward A., Law of Primitive Man (1954; repr. 1968); Llewellyn, Karl, Jurisprudence: Realism in Theory and Practice (1962); Merryman, John H., The Civil Law Tradition (1969); Pound, Roscoe, An Introduction to the Philosophy of Law (1921; repr. 1954). See also: \Tdivorce\t; \Tequity\t (law); \Tevidence\t; \TGermanic law\t; \THammurabi, Code of\t; \Tjury\t; \TJustinian Code\t; \Tjuvenile delinquency\t; \TMagna Carta\t; \TNapoleonic Code\t; \Tseas, freedom of the\t; \Tsocialist law\t; \Tspace law\t.