According to Hart, judges decide cases in one of two ways:
Dworkin believes that judges settle cases in at least one of these two ways:
The primary goal of Dworkin’s article is to show two things.
If he can do that, he will have shown that Hart’s theory is incomplete.
Here are some examples of principles.
Principles thus range over the topics of justice, the role of judicial precedents, and good policy.
In addition to examples, Dworkin gives us two abstract differences between principles and rules. Rules are all or nothing while principles are not and principles are assessed by their weight or importance while rules are not.
We had some questions about both points. Dworkin illustrated the first point with examples of cases where the principles applied but did not determine a decision: adverse possession and failure to perform one’s contract. In both kinds of case, courts allow people to keep the profits they got from doing wrong. However, Justin and Sophia were not sure that these really involved wrongdoing. If so, they don’t illustrate the point.
Helena asked why it was obvious that rules do not have weight or importance. Surely some rules are more important than others! That’s a good point. My best guess is that Dworkin thinks that in a rule-based system, a hierarchy among rules would be found in another rule. It would not be determined by whether one rule was more important than the other. But that’s a guess on my part.
Dworkin tried to show that Hart faces a dilemma. He has to choose between saying that principles are part of the law and saying that they are not part of the law. Neither alternative is palatable for Hart and there is no third option.
We were quick with the first option, that principles are not part of the law. We did that because we know Hart thought the other option was better. He had drafted a response to Dworkin that was published in the postscript of the second edition of The Concept of Law (Hart  1994). While Hart’s remarks were incomplete, his comments all concerned the second option, so that’s where we concentrated our attention.
Dworkin’s charge here is that there could not be a rule of recognition that would enable us to distinguish between the principles that are part of the law and those that are not. There could be a rule about a statute: we recognize it as law if it was passed by the legislature and signed by the executive. But what feature of principles would we single out in a rule, such that we could use the rule to say “these principles are part of the law and those are not”?
It seems to me that Hart’s best answer would be to say that we can use the familiar rules of recognition such as “if a principle is in the Constitution, it is part of the law” or “if the Courts routinely use a principle, it is part of the law,” and so on. If a principle cannot meet any of those tests, it’s not part of the law.
At the end of the day, Dworkin and Hart approach principles from two different directions. Dworkin thinks that the origins of principles are irrelevant; it’s their substance, specifically their appropriateness, that matters. For Hart, it’s the other way around: laws are determined by their origins. For Hart, a law is a rule that comes from a source that can make laws, no matter how stupid the rule is. For Dworkin, a principle has to make sense, no matter what its source is or even if it has no identifiable source at all.
I’m not sure what I think. Some years I think that Dworkin has the advantage. Other years, I think Hart is coming out ahead or, at least, not behind.
I brought up two questions at the end.
One concerns what looks to me to be a mismatch between cases like the one about the vehicles in the park and principles as a solution. Is there a principle that tells us what the right answer to the vehicles case is? Maybe if we take “principle” to mean “policy consideration” there is. But I wonder if there are always clear social advantages from deciding a case one way or the other. If not, bringing principles into the law won’t be enough to show that there is no need for judges to legislate in at least some cases.
My second point was about ex post facto legislation. (Here Daisy beat me to the punch.) Judicial legislation is bad because it means someone gets fined or punished for doing something that was not clearly against the law when it was done.
Would adding principles to the law help? I’m not sure. Since it is hard to tell how principles are weighed against one another, according to Dworkin, how can we expect an average citizen to know the answer? But if you can’t figure out what the law is, how could it be fair to punish you for violating it? Isn’t that the real problem with ex post facto laws?
I am left with the disconcerting feeling that this is a problem that simply cannot be solved. We are always going to be liable for prosecution for violating laws that we could not have known about.
Hart, H. L. A. (1961) 1994. The Concept of Law. 2nd ed. Oxford: Clarendon Press.