Judicial Precedent: The Doctrine

Introduction

Judicial precedent (also known as case law or judge-made law) is one of the most important sources of law in the English legal system. The doctrine of judicial precedent is based on the principle of stare decisis — a Latin phrase meaning "to stand by things decided." Under this doctrine, judges are bound to follow the legal principles established in previous decisions of higher courts.

Judicial precedent operates alongside statutory interpretation and legislation. While Parliament makes new law through Acts, the courts develop, refine, and apply legal principles through their decisions in individual cases. Over centuries, judicial precedent has created vast areas of law, including much of contract law, tort law, and criminal law.

This lesson examines the key concepts underpinning the doctrine of judicial precedent: stare decisis, ratio decidendi, obiter dicta, the court hierarchy, and the distinction between binding and persuasive precedent.

---

Stare Decisis

Stare decisis means "to stand by things decided" or, more fully, "stare decisis et non quieta movere" — "to stand by decisions and not disturb the undisturbed." It is the foundational principle of judicial precedent.

Under stare decisis:

• Lower courts must follow the legal principles established by higher courts in the same hierarchy
• Courts at the same level generally follow their own previous decisions (though there are exceptions)
• The legal principle from a previous case is binding on future courts if the material facts are sufficiently similar

Stare decisis promotes:

• Consistency — similar cases are decided similarly
• Certainty — people can predict the legal consequences of their actions
• Fairness — treating like cases alike
• Efficiency — judges do not need to reconsider established principles from scratch

---

Ratio Decidendi and Obiter Dicta

When a judge delivers a judgment, not every word carries the force of precedent. The doctrine of judicial precedent distinguishes between two elements of a judgment:

Ratio Decidendi

The ratio decidendi (plural: rationes decidendi) — meaning "the reason for the decision" — is the legal principle upon which the case was decided. It is the ratio that forms the binding precedent that future courts must follow.

Identifying the ratio decidendi is often difficult because:

• Judges do not always explicitly state the ratio
• Different judges in the same case may give different reasons for the same decision
• The ratio may only become clear in light of later cases that apply or distinguish it
• Academic commentators may disagree about the ratio of a particular case

Example: In Donoghue v Stevenson [1932], the ratio decidendi was the "neighbour principle" — that a manufacturer owes a duty of care to the ultimate consumer of their product. This became a binding precedent that transformed the law of negligence.

Obiter Dicta

Obiter dicta (singular: obiter dictum) — meaning "things said by the way" — are statements of law made by judges that are not strictly necessary for the decision in the case. Obiter dicta are not binding on future courts but are persuasive — future courts may choose to follow them but are not obliged to.

Obiter dicta may include:

• Hypothetical scenarios — a judge may discuss what the law would be if the facts were different
• Dissenting judgments — the reasoning of judges who disagree with the majority
• Observations on wider legal principles — comments that go beyond the specific issue in the case

Example: In R v Howe [1987], the House of Lords held that duress is not a defence to murder. The Lords also stated, obiter, that duress should not be a defence to attempted murder. This obiter dictum was later applied in R v Gotts [1992], where the court followed the obiter statement and held that duress is indeed not available for attempted murder.

Example: In Donoghue v Stevenson [1932], Lord Atkin's broader "neighbour principle" (that you must take reasonable care to avoid acts or omissions which you can reasonably foresee would be likely to injure your neighbour) went beyond the specific issue of manufacturer's liability and became an immensely influential obiter dictum that shaped the entire law of negligence.

graph TD
    A["Judgment of the Court"] --> B["Ratio Decidendi"]
    A --> C["Obiter Dicta"]
    B --> D["The legal reason for the decision"]
    B --> E["BINDING on lower courts"]
    C --> F["Statements made 'by the way'"]
    C --> G["PERSUASIVE only — not binding"]
    C --> H["Hypothetical scenarios"]
    C --> I["Dissenting judgments"]
    style B fill:#27ae60,color:#fff
    style C fill:#f39c12,color:#fff

---

Original Precedent

An original precedent is created when a court decides a point of law for the first time — where there is no existing precedent to follow. The judge must reason by analogy, consider policy arguments, and establish a new legal principle.

Original precedents are relatively rare in modern times because most legal issues have been considered in previous cases. However, new technologies, social changes, and novel legal arguments can create situations where original precedent is needed.

Example: Hunter v Canary Wharf Ltd [1997] — The House of Lords had to decide whether interference with television reception by a large building could constitute a private nuisance. This was an original precedent because no previous case had addressed this issue. The Lords held that it could not.

---

Binding vs Persuasive Precedent

The distinction between binding and persuasive precedent is fundamental to the doctrine of judicial precedent.

Binding Precedent

A binding precedent is a legal principle that a court must follow, regardless of whether the judge agrees with it. A precedent is binding when:

1. The legal principle (ratio decidendi) was established by a higher court in the same hierarchy
2. The material facts of the current case are sufficiently similar to those of the earlier case
3. The earlier decision has not been overruled by a higher court or distinguished on the facts

Persuasive Precedent

A persuasive precedent is a legal principle that a court may follow but is not obliged to follow. Sources of persuasive precedent include:

Source	Example
Obiter dicta of higher courts	Lord Atkin's "neighbour principle" in Donoghue v Stevenson
Decisions of lower courts	A High Court decision considered by the Court of Appeal
Decisions of courts in other jurisdictions	Australian, Canadian, or New Zealand court decisions
Decisions of the Privy Council	The Privy Council's decisions are persuasive in English courts
Dissenting judgments	A dissent in an earlier case may be adopted in a later case
Academic writings	Textbooks and journal articles by legal scholars