Lon Fuller: the morality of law, and the argument with Hart

Lon Fuller held the most prestigious post in American legal philosophy, and became the best known American advocate of natural law in the twentieth century. His exchange with H.L.A. Hart in the Harvard Law Review in 1958 — his contribution being a reply to Professor Hart on positivism and fidelity to law — is the standing modern statement of the quarrel between positivism and natural law.

The positivist says that whether a rule is law is one question and whether it is a good rule is another. Fuller's answer is not that law must be morally good in its content. It is subtler, and it is the reason he is worth learning: a system of rules must satisfy certain conditions before it is capable of being a legal system at all, and those conditions are themselves moral.

In The Morality of Law, Fuller distinguishes two moralities:

| | What it is | |---|---| | The internal morality of law | An application of the principles of social order to the legal process. It is represented by his exploration of the principles of legality — described as the morality that makes law possible. | | The external morality of law | The goodness, or lack of it, of the substantive law. |

Fuller stated eight canons of the internal morality of law. What is notable, and what the critics fastened on, is the imbalance in his work: the internal or procedural aspects are extensively developed, while substantive natural law is not. The yearning for justice remains important to him, but its specific content receives short shrift.

Natural law that is really positive law. One of Fuller's first points is that much of what claims to be natural law is in reality only a competing form of positive law. He made the point in the 1958 reply to Hart, against claims then current about duties asserted on religious authority. The observation matters because it removes the easiest objection to natural law — that it is somebody's morality dressed up as law — from the natural lawyer's own side of the argument.

Managerial direction and the limits of justice. Fuller's analysis of managerial direction shows that only five of the eight canons can apply to it. Managerial direction requires a rule-free response to changing conditions: decisions about who should perform a particular task and when, or who will get how much of what, call for the exercise of discretion — a discretionary power of distributive justice not suitable for governance by general rule. The conclusion is severe and examinable: judgments of justice can be made only where there are general rules which can actually be applied to situations, and the absence of rules implies an inability to make judgments of justice.

Aristotle. Both Hart and Fuller considered Aristotle the person who had something important to say about justice; Hart begins his chapter on justice in The Concept of Law by drawing a distinction he takes from Aristotle. The common ancestor is worth naming in an answer, because it shows that the disagreement between the two is narrower than it is usually made out to be.

• The natural lawyers were disappointed. They had waited a long time for the second book and found in it nothing they recognised as natural law, because they were looking for a substantive content of justice. There were a number of disappointed reviews; one reviewer called Fuller's natural law technological, another accused him of a limitation upon the scope of jurisprudence, and a third found his substantive natural law very disappointing.
• The neglect of substantive natural law was not casual — Fuller had thought about the subject long and deeply, and it would be inaccurate to call him a sceptic about the possibility of substantive justice. An answer that treats the omission as an oversight has misread him.

• The debate question. Discuss the relationship between law and morality with reference to the Hart and Fuller debate. State the positivist separation, then Fuller's move: the conditions of legality are themselves moral, so the separation cannot be as clean as the positivist supposes.
• The trap. Do not attribute to Fuller the claim that an unjust rule is not law. His argument is about the internal morality — the conditions under which a system of rules can function as law at all — and he says comparatively little about the substantive justice of any particular rule.