Why Does Legal Precedent Matter?

Author: Tim Platnich

Date: October 3, 2025

I am in the process of writing a book on the history of the English Common Law with a Canadian context in mind. In the course of researching and drafting the book, it struck me how the law has evolved slowly and cautiously over at least 800 years. Principles recognized during the Norman period of English history still operate within our legal system today. William the Conquerer, rather than imposing law from Normandy upon his new subjects, declared that the laws and customs as they existed in Anglo-Saxon England would continue unless and until modified by him. In other words, he respected the Anglo-Saxon law as it had developed over the previous centuries.

The common law started with custom. Legal scholars,  if I may call them that, going back at least to Alfred the Great, reviewed and collected existing customs and codified them. Codified is probably too strong a word. The customs, as identified, informed rulers, and their councillors, of the rules to govern the people. Various Anglo-Saxon kings, then Norman and Angevin kings, up to and including Edward I, and their advisors, including Glanville and Bracton, documented the laws and customs as they existed at various points in time.

Custom was always the underlying and driving force of the law. Following the establishment of the King's Courts, judges, when deciding a case, always had regard to custom as they understood it. The works of Glanville and Bracton were resources as they compiled what those customs were and how they were applied in the King's Courts.

This reliance on custom gave the law stability. The laws changed slowly over time. In the early days of what came to be known as statutory law, those laws always purported to be declarations of existing laws. Kings were loath to suggest they were creating new laws. Judicial decisions and early statutory law only incrementally changed as influenced by changing customs.

The idea of binding legal precedent unfolded over the course of centuries. Judges steeped their decisions in custom, including judicial custom, as it were.

The common law thus evolved incrementally and organically. It reflected settled wisdom and was rarely innovative. It changed slowly as customs changed. Common law was the result of a process of trial and error. What worked continued; what did not work slowly withered and disappeared. It was the legal version of Darwin's natural selection.

Many of our legal principles today have survived the test of time.

Judges who feel unrestricted by the common law are apt to error. They place their perceived intelligence above learned experience developed over centuries. They know better than the hundreds or thousands of judges who fashioned the law before them.

No greater example of this hubris can be demonstrated than the apparent view of Chief Justice Wagner of the Supreme Court of Canada that precedents older than a few decades have no legal value. See here.

A judiciary unbridled from legal precedent is more likely to trample rights than to honour them. Rights become arbitrary. The law becomes arbitrary. The ancient common law right of freedom of expression, enshrined in the Charter, gets trampled by new ideologies peddled by activists, accepted by progressive judges, branding any dissenters as deniers and haters.

Some will argue, not without merit, that sometimes the law must change quickly. In this circumstance, however, is it the role of the courts in a democracy to abandon precedent and change the law?

Attempts to change the law radically have historically led to violent clashes, even revolutions. It may be argued that these conflicts were the result of laws falling out of step with changing culture. The French Revolution may be cited as an example. On the other hand, the Stuart kings violently refused to accept the evolution of the law over centuries which saw parliament as an increasing curb to royal prerogative resulting in a civil war and the temporary formation of a commonwealth government.

Increasing judicial activism, if it falls out of step with democratic sympathies and custom, may lead to a revolution of sorts: a temptation on the part of popular governments to ignore judicial decisions. Governments that have popular support, would win this battle as the judiciary relies upon government to respect and enforce judicial decisions.

The history of the common law is evidence that incremental changes in the law are a more stable platform than are abrupt, ideological driven changes. Let's keep historical and legal precedents in mind before we radically try to change the law.