Note: Thus far, I have reviewed the first three chapters of Tom Bingham’s classic Rule of Law. (See here, here, and here.) Today, I will review Chapter 4.

Judge Bingham draws a key distinction between “judgment” and “discretion” in Chapter 4 of his book. In brief, for Bingham, the rule of law requires that “questions of legal right and liability should [he really means must] … be resolved by application of the law [i.e. “judgment”] and not the exercise of discretion.” But does this string of words/rule of thumb make any sense in the real world? As it happens, there is a big problem with Bingham’s formulation: the problem of hard cases, a problem made famous in scholarly circles by the late Ronald Dworkin. (See here, for example.)

To the point, the problem with Bingham’s purported distinction between “judgment” and “discretion” is that the exercise of discretion is unavoidable whenever we are dealing with hard cases. Moreover, every case that makes it to the Supreme Court is a hard case. Why? Because, by definition, there are plausible and good-faith arguments on both sides of the legal issue in question. (Otherwise, the case wouldn’t have gone up to the Supreme Court in the first place!) So, what is a “hard case”? Simply put, a hard case is a legal controversy in which a question of law or question of fact is open to multiple — and competing — interpretations.

Is a fish, for example, a “tangible object” under the Sarbanes-Oxley Act? That was the novel legal question posed in the case of Yates v. United States. Do murdering heirs forfeit their inheritance rights? That was the question in Riggs v. Palmer. What about a simple municipal ordinance that prohibits “motor vehicles” in city parks? Does the term “motor vehicle” apply to drones or other unmanned aerial vehicles (UAVs)? That is a variation of a famous hypothetical posed by the legal philosopher H.L.A. Hart, a simple hypothetical from the 1950s that continues to generate tons of scholarly literature to this day. (See here, here, and here, for example.) I could go on and on: the only limit to finding hard cases is one’s imagination!

Is there any way of shutting the lid to this legal Pandora’s box. One possible solution is the doctrine of stare decisis, i.e. binding precedent. Alas, this celebrated common law rule doesn’t always solve the problem of hard cases. Instead, it poses a new problem: the problem of argument by analogy. Simply put, for stare decisis to work, we must agree when two different cases are sufficiently alike so as to merit the same outcome. The problem, however, as every first-year law student learns during the first week of law school, is that there are no universally-accepted rules for deciding when two cases are sufficiently similar. Argument by analogy is often a judgment call!