Philosophy of Law Spring 2018

Hart on Judges


Hart’s primary aim is to defend what he calls the separation of law and morality: the question “is this the law?” is one thing while the question “is it a morally good law?” is another thing. Hart agrees with Bentham, Austin, and Holmes that the two questions should be kept separate.

The article considers two challenges to this position.

One turns on the fact that statutes and past court decisions sometimes do not have an exact, determinate application to particular cases. Critics of the separation of law and morality think that the solution to the problem of indeterminacy lies in including considerations of how the law ought to be as a part of the law. If so, then answering question “what is the law?” sometimes requires answering the question “what ought the law be?,” contrary to Hart’s view that the two questions are completely separate.

The other challenge comes from the experience of a society with immoral laws: Nazi Germany. Critics such as Gustav Radbruch allege that a belief in the separation of law and morality led to failures to criticize Nazi law on moral grounds. The post-war courts in Germany seem to have taken this lesson to heart by refusing to recognize the validity of a law passed during the Nazi period that they deem to have been immoral.


Sophia is a judge hearing a case brought by Niyati against Miriam’s rickshaw business. Miriam is pulling her rickshaw through the park and Niyati claims that this violates the law prohibiting vehicles in the park. The statute does not say what counts as a vehicle and the past cases have all involved cars. How does Judge Sophia determine what the law is in this case?

Critics of the attempt to separate the questions “what is the law?” and “what ought the law be?” think that it has produced bad decisions by judges who find it convincing. As they see it, judges who take this distinction seriously try to wall their decisions off from any consideration of what would make sense. Instead, they grab the statutes and past court decisions and look for any reason to make a decision, no matter how mindless it is. Thus, for instance, they could see that all past cases have been about things that are normally used on land, capable of carrying a person, and capable of being self-propelled and use these as criteria for determining what a vehicle is. Thus neither helicopters nor rickshaws would count as vehicles while large, battery-powered toy cars would. Allowing helicopter landings in the park and banning children’s toys doesn’t make much sense, but, the critics say, that’s what you can get if you insist on a separation of the way the law is and the way it ought to be.

Hart has two chief things to say about this line of thinking (Hart 1958, 614–15).1

First, he says that it would be clearer to simply admit that judges are making law when they decide cases on the basis of indeterminate statutes and precedents. As Hart sees it, what the critics are doing is pointing out that there are methods judges could use to make law that are bad. That is easily expressed using the distinction between law and morality. By contrast, the alleged merger of law and morality is, in his opinion, murky.

Second, he takes a shot at the realists for exaggerating the extent to which statutes and precedents are indeterminate. Even is some applications of a law are unclear or “in the penumbra,” it does not follow that this is generally true. Most laws have quite clear application which is why it is pretty easy for us to follow them. This strikes me as a fine point, but I have to confess that I am not sure about how it bears on the question of whether it is desirable to separate law and morality or not. It shows that you can get by with the separation of law and morality in most cases. But the critics said you can’t do so for some cases, namely, the indeterminate ones.

I said that while I appreciate the clarity of Hart’s position, I would feel better about it if he had said more about the kinds of considerations that judges can use. Can a judge decide a case one way because it would help her family? I hope not! I suppose Hart would say that it depends on the rules of the legal system. In a very corrupt legal system, a judge might be allowed to do that whie in ours a judge cannot. So in the first case, even a corrupt decision would change the law while in the second it would not. In any event, that is the kind of thing I would like to hear more about.

Conflicts between law and morality

If law and morality are completely separate, then there can be valid laws that are morally bad and should not be obeyed. Hart agrees with Austin and Bentham’s opinion that if laws reach “a certain degree of iniquity then there would be a plain moral obligation to resist them and to withhold obedience” (Hart 1958, 616–17).

However, critics maintain that the belief in a separation of law and morality has the opposite effect because it leads them to think that moral criticisms of the law are inappropriate. The fourth section of Hart’s article contains a discussion of the views of a German scholar who repudiated his former endorsement of the spearation of law and morality: Gustav Radbruch. Specifically, Hart discusses a case in which a court rejected a defense of having acted according to the law during the Nazi period on the grounds that the law in question was immoral and so not a genuine law.

Hart thinks this was a mistake. The Nazi law was bad law, but it was still valid law. So the only alternatives were either to accept the woman’s defense or to punish her under a retrospective or ex post facto law.

Hart makes it clear that he thinks there would be a significant cost to punishment under retrospective law. How can it be fair to punish people on the basis of laws made after they did the things for which they are punished? His point is only that this is what the court was doing, in fact, and that it would have been better to acknowledge this explicitly.

However, there is a significant problem for Hart here too. If judges make law when they decide penumbral cases, aren’t they punishing people on the basis of retrospective law too? If Sophia finds Miriam guilty of driving a vehicle in the park, she is going to be fined for behavior that was not clearly illegal at the time she engaged in it. Rickshaws will be definitively classified as vehicles for the purpose of the law only when Sophia makes her decision, after all.

More generally, I think there are significant questions Hart leaves unanswered about how judges are supposed to approach cases where law and morality conflict. Say I am a judge who is asked to apply a grossly immoral law. I could say “this is the law, but it is grossly immoral so I am going to follow Austin and Bentham’s advice and resist applying it.” Or I could say “this is grossly immoral, but it is the law so I am going to do something grossly immoral and apply it as it stands.” Neither option sounds very good.

I think that is part of the appeal of some sort of merger between law and morality. If law and morality were not separate, a judge would have a third option: “this statute is too grossly immoral to be part of the law so I am not going to apply it.”

Something like that seems to have been going on in the case I described on the first day: the court refused to enforce the provision of the will that would have allowed the man collect an inheritance from the estate of the grandfather he murdered on the grounds that no one should profit from his own wrongdoing. That was not part of the statute of wills; it was a moral principle that the court applied to the case. Our next author, Ronald Dworkin, will argue that cases like this show there is a significant flaw in Hart’s theory.

Main points

These are the things you should know or have an opinion about from today’s class.

  1. What are the advantages of separating law as it is from law as it ought to be?
  2. How does the vehicles in the park case suggest that laws are indeterminate?
  3. What happens in the Nazi law case.
  4. Why ex post facto laws are bad.
  5. Why the merger of law and morality seems to avoid the problem of ex post facto laws.


Hart, H. L. A. 1958. “Positivism and the Separation of Law and Morals.” Harvard Law Review 71 (4): 593–629.

  1. These points follow a digression about how the question “how ought the law be?” is not necessarily the same thing as “what would a morally good law be?” This is because you could use “ought” in a variety of non-moral ways. Thus, for example, the failed thief might say “I ought to have disabled the alarm system first” (Hart 1958, 612–14). Camilla asked about this but I did not got back to it in class. It’s a valid point, but probably not worth the time Hart spent on it.