What is law? — Hart and positivism

This note addresses the foundational question of analytical jurisprudence: what is law? It focuses on H.L.A. Hart's influential answer, articulated in The Concept of Law (1961, 2nd ed. 1994), and situates his positivist account within the broader tradition of legal positivism inaugurated by Bentham and Austin.

Hart's project is descriptive and general: he seeks to identify the necessary and sufficient features that distinguish legal systems from other forms of social ordering (custom, morality, etiquette). His answer—centred on the union of primary and secondary rules and the rule of recognition—aims to explain law's normativity, systemic character, and openness to moral criticism without collapsing law into morality.

The note proceeds by examining Hart's critique of Austin's command theory (§02), the core principles of Hart's positivism (§03), and the (limited) role of statutes in jurisprudence as an analytical discipline (§04). It then explores how Hart's ideas have been tested, refined, and challenged by Fuller, Raz, Finnis, and Dworkin (§§06–07), compares Hart's approach to other positivist and non-positivist traditions (§08), and concludes with tutorial-style worked examples and exam guidance (§§09–10).

Mastery of this material is essential. Hart remains the starting point for almost all contemporary debates in legal theory, and Oxford examiners expect you to engage with his arguments in depth, not merely summarise them.

Legal positivism, in the Anglo-American tradition, begins with Jeremy Bentham and John Austin. Austin's Province of Jurisprudence Determined (1832) proposed a command theory of law: laws are commands issued by a sovereign (a person or body habitually obeyed and obeying no one else) backed by threats of sanction. On this account, the existence and content of law are determined by social facts (the sovereign's commands), not by moral merit. This is the separation thesis: law and morality are conceptually distinct, even if they may overlap in content.

Austin's theory was dominant in 19th-century England but faced mounting criticism. It struggled to explain:

• Power-conferring rules: rules that create legal powers (e.g. to marry, make wills, legislate) cannot plausibly be modelled as orders backed by threats.
• Continuity of legal authority: the sovereign's death or replacement destabilises the entire legal order under Austin's model.
• Customary and judge-made law: these do not fit the picture of commands issued by a determinate sovereign.
• The internal point of view: Austin's account treats law purely from the external observer's standpoint, ignoring the perspective of those who accept and use law as a guide to conduct.

By the mid-20th century, Austin's theory was widely regarded as inadequate. Scandinavian realists (e.g. Olivecrona, Ross) and American realists (e.g. Holmes, Frank) offered sceptical, prediction-based accounts of law. Hans Kelsen, in The Pure Theory of Law, developed a sophisticated normative positivism centred on the Grundnorm. Against this backdrop, H.L.A. Hart sought to rehabilitate positivism by providing a more nuanced, sociologically informed account.

Hart's ambition was to preserve the separation thesis while remedying Austin's defects. His method was analytical: he examined ordinary legal discourse and practice to identify law's characteristic features. In this sense, Hart is both a positivist and a conceptual analyst in the tradition of mid-century Oxford philosophy (notably influenced by J.L. Austin's ordinary-language philosophy).

Hart's theory rests on several interlocking principles.

The Union of Primary and Secondary Rules

Hart argues that a legal system is the union of primary rules (imposing duties) and secondary rules (conferring powers to create, change, and adjudicate primary rules). A society with only primary rules—what Hart calls a 'pre-legal' society—suffers from three defects:

1. Uncertainty: it is unclear which rules bind the community.
2. Static character: the rules cannot be deliberately changed.
3. Inefficiency: there is no authoritative mechanism for determining whether a rule has been broken.

Secondary rules remedy these defects:

• The rule of recognition provides criteria for identifying valid legal rules, resolving uncertainty.
• Rules of change confer power to introduce, modify, or repeal rules (e.g. legislative procedures).
• Rules of adjudication confer power to determine authoritatively whether primary rules have been violated and to impose sanctions (e.g. judicial procedures).

The rule of recognition is particularly central. It is a social rule: it exists as a matter of convergent practice among officials (especially judges), who accept it as a standard for identifying law. The rule of recognition is ultimate: its validity is not determined by any higher rule within the system, but by the fact that officials accept it. This acceptance involves an internal point of view: officials treat the criteria as reasons for action, not merely predictions of sanctions.

The Internal Point of View

Hart distinguishes between:

While jurisprudence is not a case-law subject, certain landmark decisions illuminate or challenge Hart's theory.

R v. Dudley and Stephens (1884) 14 QBD 273

This case—involving the killing and eating of a cabin boy by shipwrecked sailors—is often cited in jurisprudence for its explicit rejection of a necessity defence and its affirmation of law's moral independence. Lord Coleridge CJ refused to allow moral intuitions about survival to override the prohibition on murder, illustrating the separation thesis: law may diverge from morality or utilitarian calculation.

Riggs v. Palmer (1889) 115 NY 506 (New York Court of Appeals)

Dworkin's favourite case. Elmer Palmer murdered his grandfather to inherit under the will. The court denied inheritance, invoking the principle that 'no one shall profit from his own wrong', despite no explicit statutory bar. Dworkin argues this shows that legal reasoning appeals to principles, not just rules, and that Hart's rule of recognition cannot capture this. Hart's response: the judge exercised discretion within the open texture of the statute.

Anisminic Ltd v. Foreign Compensation Commission [1969] 2 AC 147

The House of Lords held that a statutory 'ouster clause' ('determination by the Commission shall not be called in question in any court') did not preclude judicial review of jurisdictional errors. This case illustrates the UK rule of recognition's implicit criteria: even explicit statutory language may be overridden or interpreted restrictively in light of rule-of-law principles. Hart's theory accommodates this if the rule of recognition incorporates such principles.

Madzimbamuto v. Lardner-Burke [1969] 1 AC 645

After Rhodesia's unilateral declaration of independence (UDI) in 1965, the Privy Council faced the question whether Rhodesian courts were bound by post-UDI legislation from the illegal Smith regime. The Privy Council held that legality depended on continued allegiance to the Crown. This case raises Hartian questions: has the rule of recognition in Rhodesia changed? If officials accept UDI law, has a new legal system come into being? Hart discusses revolutions and secessions as moments when the rule of recognition shifts, identifiable only ex post by officials' convergent practice.

R (Privacy International) v. Investigatory Powers Tribunal [2019] UKSC 22

The Supreme Court divided on whether Parliament can oust judicial review entirely. The majority held that an ouster clause would need to use exceptionally clear language. Lord Carnwath and Lord Lloyd-Jones dissented, arguing that parliamentary sovereignty permits absolute ouster. This case probes the content of the UK rule of recognition: does it include rule-of-law constraints that Parliament cannot override, or is parliamentary sovereignty unlimited?

Reference re Secession of Quebec [1998] 2 SCR 217 (Supreme Court of Canada)

The Court held that unilateral secession would be unconstitutional but that, following a clear referendum result, there would be a constitutional duty to negotiate. This case illustrates Hart's account of legal systems' emergence and dissolution: the question is whether a new rule of recognition comes to be accepted by officials and citizens.

German Post-War Cases: Gustav Radbruch's Formula

Post-1945 German courts grappled with Nazi-era informants prosecuted for denunciations that were 'legal' under Nazi law. Some courts, influenced by Gustav Radbruch, held that extremely unjust 'laws' were not law at all. Hart criticised this as conceptual confusion: it is clearer to say that Nazi laws were valid but immoral, and that post-war officials justifiably refused to enforce them. Fuller countered that Nazi law lacked the internal morality of law (generality, clarity, consistency) and thus failed as law.

This historical debate remains central to jurisprudence and appears frequently in essays and exams.

Foundation

1. 'Austin's command theory fails because it cannot explain power-conferring rules.' Discuss.

• Tests understanding of Austin's theory and Hart's critique.

1. What does Hart mean by the 'internal point of view', and why is it important?

• Tests grasp of Hart's response to realism and predictive theories.

Standard

1. 'The rule of recognition is the foundation of Hart's legal positivism, but it raises more questions than it answers.' Evaluate.

• Tests critical understanding of the rule of recognition and its difficulties (indeterminacy, disagreement, change).

1. Can a legal system incorporate moral criteria for legal validity and still be positivist?

• Tests inclusive vs exclusive positivism; requires engagement with Hart, Raz, and Coleman.

Challenge

1. 'Dworkin has shown that Hart's account of law cannot explain legal practice.' Do you agree?

• Requires deep engagement with the Hart-Dworkin debate, especially principles, discretion, theoretical disagreement, and interpretation. Must defend a position, not simply narrate the debate.

Essential Primary Texts

• H.L.A. Hart, The Concept of Law (3rd ed, OUP 2012). Read chs I–VI and the Postscript. This is indispensable.
• H.L.A. Hart, 'Positivism and the Separation of Law and Morals' (1958) 71 Harvard Law Review 593.
• Lon L. Fuller, 'Positivism and Fidelity to Law—A Reply to Professor Hart' (1958) 71 Harvard Law Review 630.
• Ronald Dworkin, Taking Rights Seriously (Duckworth 1977), chs 2–3.
• Ronald Dworkin, Law's Empire (Hart Publishing 1986), chs 1, 4, 7.
• Joseph Raz, The Authority of Law (2nd ed, OUP 2009), chs 3–4 ('Legal Positivism and the Sources of Law', 'Authority, Law and Morality').
• John Finnis, Natural Law and Natural Rights (2nd ed, OUP 2011), ch I and XII.

Secondary Literature

• Leslie Green, 'Legal Positivism' in Edward N. Zalta (ed), Stanford Encyclopedia of Philosophy (online, regularly updated). Excellent overview.
• Nicola Lacey, A Life of H.L.A. Hart: The Nightmare and the Noble Dream (OUP 2004). Intellectual biography; illuminates context.
• Brian Leiter (ed), Objectivity in Law and Morals (CUP 2001). Contains influential essays on Hart and Dworkin by Raz, Waluchow, and others.
• Scott Shapiro, Legality (Belknap 2011). Planning theory of law; sophisticated inclusive positivism.
• Jules L. Coleman, The Practice of Principle (OUP 2001). Defence of inclusive positivism via conventionality.
• Andrei Marmor, Positive Law and Objective Values (OUP 2001). Exclusive positivism via social conventions.
• John Gardner, 'Legal Positivism: 5½ Myths' (2001) 46 American Journal of Jurisprudence 199. Clarifies common misunderstandings.
• Timothy Endicott, 'Herbert Hart and the Semantic Sting' in Jules Coleman (ed), Hart's Postscript (OUP 2001). Defends Hart against Dworkin's semantic sting objection.
• Jeremy Waldron, 'Normative (or Ethical) Positivism' in Coleman (ed), Hart's Postscript (OUP 2001). Explores the normative implications of positivism.
• Kristen Rundle, Forms Liberate: Reclaiming the Jurisprudence of Lon L. Fuller (Hart Publishing 2012). Sympathetic reconstruction of Fuller's procedural natural law.

Collections

• Jules Coleman & Scott Shapiro (eds), The Oxford Handbook of Jurisprudence and Philosophy of Law (OUP 2002). Comprehensive; see essays by Green, Raz, Finnis, Waldron.