Philosophy of Law

What it asks

A rule is enacted by a recognised procedure, and it is monstrous. Is it law?

The natural law tradition says no, or not fully: a sufficiently unjust rule fails to be law, whatever its pedigree. Legal positivism says yes: whether a rule is law is a matter of social fact, and whether it is just is a separate question that must be kept separate precisely so it can be asked clearly.

Note that positivism is not the view that unjust laws should be obeyed. Its central claim is that calling something law settles nothing about whether to comply, and that running the two together makes moral criticism of law harder rather than easier.

The recurring problems

The separation of law and morals. Whether legal validity depends on moral merit is the field's organising question and it survives every attempt to dissolve it.

Hard cases. When the rules run out, what does a judge do - exercise discretion and make new law, or discover what the law already required? Dworkin's argument that there is a right answer even where the rules are silent, because legal principles run deeper than rules, is the strongest challenge positivism has faced.

What justifies punishment. Deterrence justifies punishing the innocent when it works; retribution justifies suffering that helps nobody. Every theory keeps something essential and licenses something intolerable.

Legal moralism. Whether the law may enforce a society's morality where no one is harmed. The Hart-Devlin exchange in the early 1960s framed the question and remains the reference point.

How it developed

The natural law tradition runs from the Stoics through Aquinas, holding that human law derives its authority from a moral order it can fail to conform to.

Nineteenth-century positivism replaced this with the command theory: law is the command of a sovereign backed by sanction. It was clear, it was influential, and it fits almost no actual legal system, since most law confers powers rather than issuing orders.

Hart's The Concept of Law in 1961 rebuilt positivism on better foundations, with the rule of recognition - the criteria officials actually use to identify law - at its centre. It is the most influential work in the field's history.

The Hart-Fuller debate in 1958 gave the field its defining case, arising from postwar trials of people who had informed under laws since repudiated. Dworkin's sustained attack from the 1960s to Law's Empire in 1986 argued that law includes principles as well as rules and that legal reasoning is inherently interpretive and moral.

The positions within it

Natural law, legal positivism in inclusive and exclusive versions, legal realism, interpretivism, and critical legal studies. All are in the Schools section.

Legal realism's claim that what courts actually do is shaped by far more than the rules is now a background assumption rather than a position, which is what winning looks like.

Where it stands now

The classical dispute continues in a more technical register, and the growth is elsewhere: in constitutional interpretation, in international and transnational law, and in whether legal concepts built for states apply to bodies that are not states.

Automated decision-making has raised the field's oldest question in a new form. If a rule is applied by a system nobody can interrogate, the reasoning that legal legitimacy has always depended on is not available for inspection.