Philosophy of Law Spring 2024

Fuller on Law and Morality


Hart thinks that whether something counts as part of the law or not depends on how the rule of recognition is applied. For example, suppose a rule of recognition is “a bill passed by majorities in Congress and signed by the President is law.”

There is nothing about the substance or content of the bill in this condition. It is just a matter of being recognized under the rules.

Fuller thinks that is wrong and that there are substantive constraints on the law. He calls this the “inner morality” of the law.

He makes his point by discussing eight ways that the unfortunate ruler Rex fails to make law. Each failure points up a necessary feature that laws must have, according to Fuller.

What would Hart say?

Hart thinks that law consists of the union of primary and secondary rules. If Fuller can show that Rex’s efforts consist in the union of primary and secondary rules, then he will have an objection to Hart’s theory. The objection would be that Hart’s theory mistakenly holds that Rex is making law when he is, in fact, failing to make law.

Do we have secondary rules in Rex’s system? Primary rules? Are they unified? Is it obvious that Rex is failing to make law? Those would be the relevant questions.

Fuller’s argument from obligation

Fuller’s chief argument for the conclusion that law must have the eight features he identifies is that those features are necessary conditions for anyone’s being morally obliged to obey the law. This is what he says.

A total failure in any one of these eight directions does not simply result in a bad system of law; it results in something that is not properly called a legal system at all …. Certainly there can be no rational ground for asserting that a man can have a moral obligation to obey a legal rule that does not exist, or is kep secret from him, or that came into existence only after he had acted, or was unintelligible, or was contradicted by another rule of the same system, or commanded the impossible, or changed every minute. (Fuller 1969, 39)

As I understand it, this is the argument.

  1. Rex’s state has real laws only if his subjects are morally obliged to obey what he calls laws.
  2. Rex’s subjects are not morally obliged to obey what he calls laws.
  3. Therefore, Rex’s state does not have real laws.

The problem with this argument, in my opinion, is that the first premise is false. A state can have laws even if no one is morally obliged to obey them. There can be immoral laws, in my opinion. We will have a fuller, er, more complete, discussion of this next week when we read Hart on the connection between law and morality.

How important is morality here?

Suppose I am trying to direct my evil henchmen to do great evil. Wouldn’t I need to follow Fuller’s lessons when I give my orders? If so, why think they reflect a morality?

I also wonder whether Fuller’s point is more about the law than it is about connections between the law and morality. I think he is on solid ground in saying that the rule of law depends on following those eight conditions. If so, my complaints about the argument involving obligation might not matter. It appears to me that he can make his basic point without them.


Fuller, Lon L. 1969. The Morality of Law. Revised edition. New Haven: Yale University Press.