philosophy of law also called general jurisprudence, the study of conceptual and theoretical problems concerning the nature of law as such, or common to any legal system. Problems in the philosophy of law fall roughly into two groups. The first contains problems internal to law and legal systems as such. These include (a) the nature of legal rules; the conditions under which they can be said to exist and to influence practice; their normative character, as mandatory or advisory; and the (in)determinacy of their language; (b) the structure and logical character of legal norms; the analysis of legal principles as a class of legal norms; and the relation between the normative force of law and coercion; (c) the identity conditions for legal systems; when a legal system exists; and when one legal system ends and another begins; (d) the nature of the reasoning used by courts in adjudicating cases; (e) the justification of legal decisions; whether legal justification is through a chain of inferences or by the coherence of norms and decisions; and the relation between intralegal and extralegal justification; (f) the nature of legal validity and of what makes a norm a valid law; the relation between validity and efficacy, the fact that the norms of a legal system are obeyed by the norm-subjects; (g) properties of legal systems, including comprehensiveness (the claim to regulate any behavior) and completeness (the absence of gaps in the law); (h) legal rights; under what conditions citizens possess them; and their analytical structure as protected normative positions; (i) legal interpretation; whether it is a pervasive feature of law or is found only in certain kinds of adjudication; its rationality or otherwise; and its essentially ideological character or otherwise. The second group of problems concerns the relation between law as one particular social institution in a society and the wider political and moral life of that society: (a) the nature of legal obligation; whether there is an obligation, prima facie or final, to obey the law as such; whether there is an obligation to obey the law only when certain standards are met, and if so, what those standards might be; (b) the authority of law; and the conditions under which a legal system has political or moral authority or legitimacy; (c) the functions of law; whether there are functions performed by a legal system in a society that are internal to the design of law; and analyses from the perspective of political morality of the functioning of legal systems; (d) the legal concept of responsibility; its analysis and its relation to moral and political concepts of responsibility; in particular, the place of mental elements and causal elements in the assignment of responsibility, and the analysis of those elements; (e) the analysis and justification of legal punishment; (f) legal liberty, and the proper limits or otherwise of the intrusion of the legal system into individual liberty; the plausibility of legal moralism; (g) the relation between law and justice, and the role of a legal system in the maintenance of social justice; (h) the relation between legal rights and political or moral rights; (i) the status of legal reasoning as a species of practical reasoning; and the relation between law and practical reason; (j) law and economics; whether legal decision making in fact tracks, or otherwise ought to track, economic efficiency; (k) legal systems as sources of and embodiments of political power; and law as essentially gendered, or imbued with race or class biases, or otherwise.
Theoretical positions in the philosophy of law tend to group into three large kinds – legal positivism, natural law, and legal realism. Legal positivism concentrates on the first set of problems, and typically gives formal or content-independent solutions to such problems. For example, legal positivism tends to regard legal validity as a property of a legal rule that the rule derives merely from its formal relation to other legal rules; a morally iniquitous law is still for legal positivism a valid legal rule if it satisfies the required formal existence conditions. Legal rights exist as normative consequences of valid legal rules; no questions of the status of the right from the point of view of political morality arise. Legal positivism does not deny the importance of the second set of problems, but assigns the task of treating them to other disciplines – political philosophy, moral philosophy, sociology, psychology, and so forth. Questions of how society should design its legal institutions, for legal positivism, are not technically speaking problems in the philosophy of law, although many legal positivists have presented their theories about such questions. Natural law theory and legal realism, by contrast, regard the sharp distinction between the two kinds of problem as an artifact of legal positivism itself. Their answers to the first set of problems tend to be substantive or content-dependent. Natural law theory, for example, would regard the question of whether a law was consonant with practical reason, or whether a legal system was morally and politically legitimate, as in whole or in part determinative of the issue of legal validity, or of whether a legal norm granted a legal right. The theory would regard the relation between a legal system and liberty or justice as in whole or in part determinative of the normative force and the justification for that system and its laws. Legal realism, especially in its contemporary politicized form, sees the claimed role of the law in legitimizing certain gender, race, or class interests as the prime salient property of law for theoretical analysis, and questions of the determinacy of legal rules or of legal interpretation or legal right as of value only in the service of the project of explaining the political power of law and legal systems. See also DWORKIN , HART, JURISPRUDENCE , LEGAL MORALISM , LEGAL POSITIVISM , LEGAL REALISM , NATURAL LAW , POLITICAL PHILOSO – PH. R.A.Sh.