The (scientific) development of common-law precedent

Please note that this post is from 2011. Evaluate with care and in light of later events.

One of the defining characteristics of common law (as opposed to civil law) is the binding nature of precedent, sometimes referred to by its Latin name of stare decisis. But before the seventeenth century, the defining characteristic of English common law was not this one, but rather that common law reflected universal and customary law, and as such the goal was for judges to utilize previous decisions as merely guides to help them get closer to the true (unwritten) laws of England, not as binding in themselves.

For this reason, Bracton’s thirteenth-century treatise On the Laws and Customs of England “reflected the canonist [i.e., the civil law] rule … that ‘one must judge not by examples but by reasons'” (see “The Transformation of English Legal Science” by Harold Berman and Charles Reid, Jr., ):

Cases, that is, judicial decisions, could be used to illustrate legal principles, but were not themselves an authoritative source of law. … If a judge did not approve of a previous decisions, or even of a previous custom of the court, he might say it was wrong and disregard it. (445)

In the seventeenth century, this began to change. Edward Coke began some of the first modern compendiums of judicial decisions, connecting the reasoning for new cases to the authority granted by previous decisions. But this was still not binding precedent, and Coke “would reach out for anything said by a judge in an earlier case if it seemed to him to reflect a true legal principle” (447). In other words, Coke made precedent more authoritative, but the ultimate search was still for universal principles. 

The eighteenth century jurist Matthew Hale saw prior decisions as evidence of the true principle or rule (448). But judicial decisions themselves “did not make a Law properly so-called, (for that only the King and Parliament can do)” (448). In other words, judges “do not ‘make’ laws, but ‘find’ them in the received legal tradition, and ‘declare’ them” (448). Modern judicial precedent–strict stare decisis, requiring lower courts to follow previous decisions (but not dictum)–did not emerge until the nineteenth century. Before this, it was a “line of cases” that mattered, not a particular holding. Judicial custom matters because it involves multiple decisions over time. Thus, in 1762, Lord Mansfield still maintained that “[t]he reason and spirit of cases make law; not the letter of particular precedents” (449).

Berman and Reid summarize the development of precedent as follows:

1. common lawyers had always discussed cases and opinions, and did not simply look to written statutes;
2. but prior to the sixteenth century, they had “no doctrine of precedent,” and only in the seventeenth century developed a version of persuasive authority largely confined to procedure and custom;
3. Coke and others challenged the King by using pre-Tudor precedents, and thus brought precedent forward as an important part of common-law decisions;
4. but common-law courts avoided binding precedent still, and looked to prior decisions to extract the principles of judicial custom, but began to apply precedent to both procedural and substantive matters;
5. at the end of the seventeenth century, common-law courts continued to develop doctrines involving precedent, especially distinguishing dicta from holdings to extract principles that could apply to the past and the future: “the principle of precedent was a dynamic and not a static one” (450).

Berman and Reid further tie the development of precedent to scientific and empirical developments of the Enlightenment as well. Even as Robert Boyle and Isaac Newtown emphasized reason and evidence in their scientific pursuits, so too did English jurists seek the “professional verification and acceptance of empirical observation” (450). Thus, repeated applications of similar approaches became good empirical evidence for the validity of a rule, “just as the repeated confirmation of the results of scientific experiments by physicists and chemists was treated as proof of the probable truth of their findings” (451).