Herbert Lionel Adolphus Hart (1907-92) was a British philosopher who was professor of jurisprudence at the University of Oxford. His most important writings included Causation in the Law (1959, with A.M. Honoré), The Concept of Law (1961), Law, Liberty and Morality (1963), Of Laws in General (1970), and Essays on Bentham (1982).
The Concept of Law (1961) is an analysis of the relation between law, coercion, and morality, and it is an attempt to clarify the question of whether all laws may be properly conceptualized as coercive orders or as moral commands. Hart says that there is no logically necessary connection between law and coercion or between law and morality. He explains that to classify all laws as coercive orders or as moral commands is to oversimplify the relation between law, coercion, and morality. He also explains that to conceptualize all laws as coercive orders or as moral commands is to impose a misleading appearance of uniformity on different kinds of laws and on different kinds of social functions which laws may perform. He argues that to describe all laws as coercive orders is to mischaracterize the purpose and function of some laws and is to misunderstand their content, mode of origin, and range of application.
Laws are rules that may forbid individuals to perform various kinds of actions or that may impose various obligations on individuals. Laws may require individuals to undergo punishment for injuring other individuals. They may also specify how contracts are to be arranged and how official documents are to be created. They may also specify how legislatures are to be assembled and how courts are to function. They may specify how new laws are to be enacted and how old laws are to be changed. They may exert coercive power over individuals by imposing penalties on those individuals who do not comply with various kinds of duties or obligations. However, not all laws may be regarded as coercive orders, because some laws may confer powers or privileges on individuals without imposing duties or obligations on them.
Hart criticizes the concept of law that is formulated by John Austin in The Province of Jurisprudence Determined (1832) and that proposes that all laws are commands of a legally unlimited sovereign. Austin claims that all laws are coercive orders that impose duties or obligations on individuals. Hart says, however, that laws may differ from the commands of a sovereign, because they may apply to those individuals who enact them and not merely to other individuals. Laws may also differ from coercive orders in that they may not necessarily impose duties or obligations but may instead confer powers or privileges.
Laws that impose duties or obligations on individuals are described by Hart as "primary rules of obligation." In order for a system of primary rules to function effectively, "secondary rules" may also be necessary in order to provide an authoritative statement of all the primary rules. Secondary rules may be necessary in order to allow legislators to make changes in the primary rules if the primary rules are found to be defective or inadequate. Secondary rules may also be necessary in order to enable courts to resolve disputes over the interpretation and application of the primary rules. The secondary rules of a legal system may thus include 1) rules of recognition, 2) rules of change, and 3) rules of adjudication.
In order for the primary rules of a legal system to function effectively, the rules must be sufficiently clear and intelligible to be understood by those individuals to whom they apply. If the primary rules are not sufficiently clear or intelligible, then there may be uncertainty about the obligations which have been imposed on individuals. Vagueness or ambiguity in the secondary rules of a legal system may also cause uncertainty as to whether powers have been conferred on individuals in accordance with statutory requirements or may cause uncertainty as to whether legislators have the authority to change laws. Vagueness or ambiguity in the secondary rules of a legal system may also cause uncertainty as to whether courts have jurisdiction over disputes concerning the interpretation and application of laws.
Primary rules of obligation are not in themselves sufficient to establish a system of laws that can be formally recognized, changed, or adjudicated, says Hart. Primary rules must be combined with secondary rules in order to advance from the pre-legal to the legal stage of determination. A legal system may thus be established by a union of primary and secondary rules (although Hart does not claim that this union is the only valid criterion of a legal system or that a legal system must be described in these terms in order to be properly defined).
Hart distinguishes between the "external" and "internal" points of view with respect to how the rules of a legal system may be described or evaluated. The external point of view is that of an observer who does not necessarily have to accept the rules of the legal system. The external observer may be able to evaluate the extent to which the rules of the legal system produce a regular pattern of conduct on the part of individuals to whom the rules apply. The internal point of view, on the other hand, is that of individuals who are governed by the rules of the legal system and who accept these rules as standards of conduct.
The "external" aspect of rules may be evident in the regular pattern of conduct which may occur among a group of individuals. The "internal" aspect of rules distinguishes rules from habits, in that habits may be viewed as regular patterns of conduct but are not usually viewed as standards of conduct. The external aspect of rules may in some cases enable us to predict the conduct of individuals, but we may have to consider the 'internal' aspect of rules in order to interpret or explain the conduct of individuals.
Hart argues that the foundations of a legal system do not consist, as Austin claims, of habits of obedience to a legally unlimited sovereign, but instead consist of adherence to, or acceptance of, an ultimate rule of recognition by which the validity of any primary or secondary rule may be evaluated.1 If a primary or secondary rule satisfies the criteria which are provided by the ultimate rule of recognition, then that rule is legally valid.
There are two minimum requirements which must be satisfied in order for a legal system to exist: 1) private citizens must generally obey the primary rules of obligation, and 2) public officials must accept the secondary rules of recognition, change, and adjudication as standards of official conduct.2 If both of these requirements are not satisfied, then primary rules may only be sufficent to establish a pre-legal form of government.
Moral and legal rules may overlap, because moral and legal obligation may be similar in some situations. However, moral and legal obligation may also differ in some situations. Moral and legal rules may apply to similar aspects of conduct, such as the obligation to be honest and truthful or the obligation to respect the rights of other individuals. However, moral rules cannot always be changed in the same way that legal rules can be changed.
According to Hart, there is no necessary logical connection between the content of law and morality, and that the existence of legal rights and duties may be devoid of any moral justification.3 Thus, his interpretation of the relation between law and morality differs from that of Ronald Dworkin, who in Law’s Empire suggests that every legal action has a moral dimension. Dworkin rejects the concept of law as acceptance of conventional patterns of recognition, and describes law not merely as a descriptive concept but as an interpretive concept which combines jurisprudence and adjudication.
Hart defines legal positivism as the theory that there is no logically necessary connection between law and morality. However, he describes his own viewpoint as a "soft positivism," because he admits that rules of recognition may consider the compatibility or incompatibility of a rule with moral values as a criterion of the rule’s legal validity.4
Legal positivism may disagree with theories of natural law, which assert that civil laws must be based on moral laws in order for society to be properly governed. Theories of natural law may also assert that there are moral laws which are universal and which are discoverable by reason. Thus, they may fail to recognize the difference between descriptive and prescriptive laws. Laws that describe physical or social phenomena may differ in form and content from laws which prescribe proper moral conduct.
Hart criticizes both formalism and rule-scepticism as methods of evaluating the importance of rules as structural elements of a legal system. Formalism may rely on a rigid adherence to general rules of conduct in order to decide which action should be performed in a particular situation. On the other hand, rule-scepticism may not rely on any general rule of conduct in order to decide which action should be performed in a particular situation. Formalism may produce such inflexibility in the rules of a legal system that the rules are not adaptable to particular cases. Rule-scepticism may produce such uncertainty in the application of the rules of a legal system that every case has to be adjudicated.
International law is described by Hart as problematic, because it may not have all of the elements of a fully-developed legal system. International law may in some cases lack secondary rules of recognition, change, and adjudication. International legislatures may not always have the power to enforce sanctions against nations who disobey international law. International courts may not always have jurisdiction over legal disputes between nations. International law may be disregarded by some nations who may not face any significant pressure to comply. Nations who comply with international law must still be able to exercise their sovereignty.
In any legal system, there may be cases in which existing laws are vague or indeterminate and that judicial discretion may be necessary in order to clarify existing laws in these cases. Hart also argues that by clarifying vague or indeterminate laws, judges may actually make new laws. He explains that this argument is rejected by Ronald Dworkin, who contends that judicial discretion is not an exercise in making new laws but is a means of determining which legal principles are most consistent with existing laws and which legal principles provide the best justification for existing laws.5
Dworkin says in Law’s Empire that legal theory may advance from the "preinterpretive stage" (in which rules of conduct are identified) to the "interpretive stage" (in which the justification for these rules is decided upon) to the "postinterpretive stage" (in which the rules of conduct are reevaluated based on what has been found to justify them).6 A complete legal theory does not merely identify the rules of a legal system, but also interprets and evaluates them. A complete legal theory must consider not only the relation between law and coercion (i.e. the "force" of law), but the relation between law and rightfulness or justifiability (i.e. the "grounds" of law). Thus, Dworkin argues that a complete legal theory must address not only the question of whether the rules of a legal system are justified but the question of whether there are sufficient grounds for coercing individuals to comply with the rules of the system.