Schools of Legal Thought Compared
What is law? Is an unjust law still law? How should a judge decide? Each school of legal thought answers differently. This guide sets 17 schools side by side on the same questions, from natural law and positivism to realism, critical theory and the great traditions outside the West.
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| Question | Natural Law TheoryAncient Greece and Rome to today · Greece, Rome, medieval Europe, then worldwide | Legal PositivismLate 18th century to today · England and Austria, then worldwide | American Legal Realism1920s and 1930s, with roots in Holmes · United States |
|---|---|---|---|
| In one line | Law gets its force from morality: a gravely unjust rule is not truly law, or not fully law. | Law is what the proper authorities have laid down, whatever its moral merit. | Law is what courts actually do; judges are people, and their reasons are not only the rules. |
| What is law? | Law is a rational ordering of human affairs for the common good. Human-made (positive) law is law in the full sense only if it fits a higher standard of reason or morality that people can discover, often called the natural law. | Law is a social fact: a rule is law because it was made, recognised or accepted in the right way within a legal system, not because it is just. Bentham and Austin saw law as the commands of a sovereign, Kelsen as a hierarchy of norms, and Hart as primary rules plus secondary rules, resting on a rule of recognition. | Law is the prediction of what courts will do in fact. Rules matter less than the human, social and economic facts that shape decisions. |
| Law and morality | Tightly connected. Most versions say a seriously unjust rule lacks the full moral force of law. The classic slogan, from Augustine and Aquinas, is that an unjust law is a corruption of law rather than law. | Conceptually separate. Positivists do not say law is always moral or must always be obeyed, only that whether a rule is law is one question and whether it is good is another. | Not separate: judges make policy choices, openly or not, and scholars should study those choices with the help of the social sciences. |
| Where does its authority come from? | Reason, human nature or God's order, depending on the thinker: the Stoics and Cicero (reason in nature), Aquinas (reason taking part in eternal law), Grotius (natural law valid even without God), Finnis (basic goods of human flourishing). | The facts of social practice: who makes the rules, and what officials accept as the sources of law (statutes, precedent, custom). | The behaviour of courts and officials. |
| How should judges decide? | Citizens and judges may ask whether a rule respects basic justice, and in extreme cases a rule that violates fundamental rights may be refused effect. The post-war Radbruch formula in Germany is the best-known modern example. | Judges apply the valid rules, and where the rules run out they use discretion. Whether they may bring in moral reasoning is debated between inclusive and exclusive positivists. | Judges should recognise that they make choices and look at the real consequences of their decisions. Scholars should observe how courts behave. |
| The question it asks | Can an unjust rule really be law? | What makes a rule a valid rule of law? | How do judges really decide? |
| Main criticism | Critics say it blurs the difference between what the law is and what it ought to be, that people disagree about what morality requires, and that calling an unjust rule 'not law' makes it harder to describe unjust legal systems honestly. | Natural lawyers say it cannot explain why law claims authority or how to treat monstrous regimes. Dworkin says it ignores legal principles. Others say law is not only rules. | Hart and others said the prediction theory ignores the point of view of people who accept rules as reasons for action, and that realists overstate how unpredictable law is. |
| Legacy today | Human rights law, the Nuremberg principles, the claim to unalienable rights in the American Declaration of Independence, and arguments about conscience and unjust laws. | The way most courts and law schools speak about sources of law, and the clarity of 'law as a social fact' in comparative law. | Empirical study of judges, the Uniform Commercial Code, law and the social sciences, and later movements such as law and economics and critical legal studies. |
| Key thinkers | Aristotle, Cicero, Thomas Aquinas, Hugo Grotius, John Locke, Lon Fuller, John Finnis, Gustav Radbruch | Jeremy Bentham, John Austin, Hans Kelsen, H.L.A. Hart, Joseph Raz | Oliver Wendell Holmes Jr., Karl Llewellyn, Jerome Frank, Benjamin Cardozo, Felix Cohen |
| Key works | Cicero, On the Laws; Aquinas, Summa Theologiae (Treatise on Law); Grotius, On the Law of War and Peace (1625); Fuller, The Morality of Law (1964); Finnis, Natural Law and Natural Rights (1980) | Bentham, Of Laws in General (written c. 1782); Austin, The Province of Jurisprudence Determined (1832); Kelsen, Pure Theory of Law (1934, 1960); Hart, The Concept of Law (1961) | Holmes, The Path of the Law (1897); Llewellyn, The Bramble Bush (1930); Frank, Law and the Modern Mind (1930) |
Read this first
This is a first map of a large subject. Each school is a family of views, and its thinkers often disagree with one another, so every summary simplifies. We describe each school in terms its own followers would accept and give the strongest criticism beside it. Read the original works before you cite anyone, and check your own course's reading list. This is general information, not legal advice.
The 17 schools
Classical and early modern
- Natural Law Theory
Law gets its force from morality: a gravely unjust rule is not truly law, or not fully law.
Ancient Greece and Rome to today
- The Historical School
Law grows out of a people's history and spirit, and cannot be invented from above.
Early 19th century
- Legal Formalism and Conceptualism
Law is a logical system of rules and concepts from which a judge can reason to the answer.
19th century
Modern analytical and empirical
- Legal Positivism
Law is what the proper authorities have laid down, whatever its moral merit.
Late 18th century to today
- American Legal Realism
Law is what courts actually do; judges are people, and their reasons are not only the rules.
1920s and 1930s, with roots in Holmes
- Scandinavian Legal Realism
Rights and duties are useful ways of speaking, with no hidden existence of their own.
1910s to 1960s
- Sociological Jurisprudence
Study law in society: what it does, whom it serves, and how living practice differs from the books.
Late 19th to mid 20th century
- Law as Integrity (Interpretivism)
Law includes the moral principles that best justify a community's legal practice.
1960s to 2010s
- Law and Economics
Judge legal rules by their effects on incentives and efficiency.
1960s to today
Critical and social movements
- Critical Legal Studies
Legal reasoning is not neutral: it is unsettled by its own contradictions and tends to support existing power.
1970s to 1990s
- Feminist Legal Theory
Law has often been written from a male standpoint: ask how it treats women, and change it.
1970s to today
- Critical Race Theory
Race and racism are built into legal institutions: examine how neutral-looking law keeps inequality in place.
1980s to today
- Marxist Legal Theory
Law belongs to a superstructure that reflects who owns the means of production.
19th and 20th centuries
- Legal Pluralism
Many normative orders besides the state's law exist side by side.
20th century to today
Outside the Western tradition
- Islamic Jurisprudence (Usul al-Fiqh)
Law is derived by qualified scholars from the revealed sources, using reasoned methods.
8th century to today
- Chinese Legalism and Confucianism
Order through strict public law, or through virtue and ritual?
6th to 3rd century BC, and after
- Classical Indian Dharma Law (Dharmashastra)
Law as dharma: duty, order and right conduct, set out by sages and upheld by kings.
c. 500 BC onward
Five famous debates
The Hart–Fuller debate (1958)
Legal positivism v natural law
After the Second World War, courts in Germany had to decide whether Nazi-era statutes were still law. Hart defended the separation of law and morality; Fuller argued that law has an inner morality, so a system that breaks basic principles of legality is not fully law.
The Hart–Dworkin debate
Legal positivism v interpretivism
Dworkin argued that judges rely on principles as well as rules, and that a judge's duty is to find the best moral reading of the law. Hart replied that principles can be identified as law by the rule of recognition, and that judges do have discretion in hard cases.
Savigny v Thibaut (1814)
Historical school v codification
Thibaut urged one German civil code to unify the states; Savigny answered that law must grow from a people's history and that Germany was not ready. The debate shaped German private law until the Civil Code of 1900.
Formalism v realism
Logic v behaviour
Formalists said judges apply rules by logic; realists answered that rules underdetermine results and that decisions are explained by judges' social experience, policy and the facts of the case.
Law v virtue in China
Legalism v Confucianism
Should a ruler keep order by strict, public law or by moral example? The two answers were fused in imperial law, but the question stays alive in modern debates on rule of law.
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