We began our review of Stephen A. Sachs’s paper “Finding Law” in our previous post. In brief, Professor Sach’s argues that “positive law” or man-made law is not the only source of law, for some laws are unwritten, much like the rules of language, the conventions of fashion, and the precepts of etiquette. In addition, Sachs states the source of this body of unwritten law is usage and social practice. We also made an additional observation in our previous post: whether by design or by accident, Sach’s unwritten law looks a lot like traditional natural law, except that Sach’s version of natural law can change over time as usages and social practices change. But Sachs’s unwritten natural law thesis poses two deeper problems: (1) discovery and (2) demarcation. That is, how do we go about discovering this body of law? And secondly, how do we distinguish this body of law from these other law-like domains, i.e. language, fashion, and etiquette?
According to Professor Sachs (p. 19), both the process of discovery and the line of demarcation revolve around “practice-plus-obligation.” (Again, all page references are to the version of the paper posted on SSRN.) Sachs cites two classic Blackstonian criteria in support of this practice-plus-obligation formulation (p. 15, quoting Sir William Blackstone (pictured below), the author of the treatise “Commentaries on the Laws of England”): “we might well identify unwritten legal rules largely as Blackstone did: by their ‘long and immemorial usage, and by their universal reception.’” But, in fact, Sachs’s rejects the “universal reception” requirement. What matters for Sachs is what such legal elites as trained lawyers and actual judges believe the law to be (p. 18): “… legal customs of elites [are] the legal customs of their society. So long as we can pick out the experts, and the experts can pick out the rules, the rules still belong to us all.”
There are two potential problems with Professor Sachs’s practice-plus-obligation formulation, however. One weakness in Sachs’ argument is the problem of disagreement. Specifically, what happens when the relevant group of people disagree about what the relevant social practice is? By definition, if people agreed on the content of the law (i.e. on the content of the relevant social practice), they would not be in court arguing over the law! In reality, the scope and meaning of the law is often a contested domain, even when the law is written down.
But let’s put aside the problem of disagreement for the sake of argument. Let’s assume people actually agree on what the law is in any given case. There is still a more serious problem with Sachs’s practice-plus-obligation formulation: circularity. (As an aside, the circularity problem also bedevils the H.L.A. Hart’s “internal point of view” theory.) It is circular since a social practice would not exist unless people felt obligated to follow it! To see why, ask yourself the following question: why do people follow a social practice? If the answer is “because they feel obligated to follow the social practice”, now ask yourself the next logical follow-up question: why do people feel obligated to follow the social practice? If the answer is “because it is a social practice”, the circularity of the practice-plus-obligation formulation becomes obvious.
Nevertheless, although we are skeptical of Sachs’s discovery and demarcation criteria, we do agree with Sachs’s thesis about the existence of an unwritten natural law. Without such a natural law, how could we criticize the old transatlantic slave trade (before it was made illegal) or the atrocities committed by Nazi Germany (before the Germans lost the war)? In our next post, we shall posit a different solution to the problems of disagreement and circularity: Oliver Wendell Holmes’s prediction theory of law. Just as we can use Holmes’s prediction theory to figure out which laws will be enforced, we can also apply this theory to the domain of natural law.