Judicial Precedent: How It Operates

Introduction

The previous lesson established the theoretical foundations of judicial precedent — stare decisis, ratio decidendi, obiter dicta, and the court hierarchy. This lesson examines how judicial precedent operates in practice: how courts avoid, modify, or depart from previous decisions.

While stare decisis promotes consistency and certainty, a rigid adherence to precedent would prevent the law from developing. The legal system therefore provides several mechanisms that allow the law to evolve while maintaining the overall framework of precedent. These mechanisms include the Practice Statement 1966, the exceptions established in Young v Bristol Aeroplane Co [1944], and the techniques of distinguishing, overruling, and reversing.

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The Practice Statement 1966

Before 1966, the House of Lords considered itself absolutely bound by its own previous decisions, as established in London Tramways Co v London County Council [1898]. This meant that even if the Lords recognised that a previous decision was wrong or outdated, they could not depart from it — only Parliament could change the law by passing an Act.

On 26 July 1966, Lord Gardiner LC issued the Practice Statement on behalf of the House of Lords:

"Their Lordships regard the use of precedent as an indispensable foundation upon which to decide what is the law and its application to individual cases. It provides at least some degree of certainty upon which individuals can rely in the conduct of their affairs, as well as a basis for orderly development of legal rules.

Their Lordships nevertheless recognise that too rigid adherence to precedent may lead to injustice in a particular case and also unduly restrict the proper development of the law. They propose, therefore, to modify their present practice and, while treating former decisions of this House as normally binding, to depart from a previous decision when it appears right to do so.

In this connection they will bear in mind the danger of disturbing retrospectively the basis on which contracts, settlements of property and fiscal arrangements have been entered into and also the especial need for certainty as to the criminal law."

Key Points About the Practice Statement

1. It only applies to the Supreme Court (formerly the House of Lords) — no other court has this power
2. It is used sparingly — the Lords/Supreme Court are reluctant to depart from their own previous decisions
3. Certainty remains important — particularly in criminal law and commercial law, where people rely on settled legal principles
4. The Practice Statement recognises that the law must be able to develop to avoid injustice

Cases Where the Practice Statement Has Been Used

graph TD
    A["Practice Statement 1966"] --> B["Used Sparingly"]
    B --> C["British Railways Board v<br/>Herrington 1972"]
    B --> D["R v Howe 1987"]
    B --> E["R v Jogee 2016"]
    B --> F["Refused in many cases"]
    F --> G["Jones v Secretary of State 1972<br/>- Too soon to use"]
    F --> H["R v Kansal No 2 2001<br/>- Certainty concerns"]
    style A fill:#8e44ad,color:#fff
    style C fill:#27ae60,color:#fff
    style D fill:#27ae60,color:#fff
    style E fill:#27ae60,color:#fff
    style F fill:#e74c3c,color:#fff

British Railways Board v Herrington [1972]

Previous decision: In Addie v Dumbreck [1929], the House of Lords had held that an occupier of land owed no duty of care to trespassers (only a duty not to intentionally harm them).

Facts in Herrington: A six-year-old boy was electrocuted after climbing through a broken fence onto an electrified railway line. British Railways knew the fence was broken and that children regularly entered the land.

Decision: The House of Lords used the Practice Statement to depart from Addie v Dumbreck. They held that an occupier does owe a duty of care to trespassers in certain circumstances — particularly where the occupier knows of the danger and knows (or ought to know) that trespassers are likely to be present.

Significance: This was the first use of the Practice Statement. It demonstrated that the Lords were willing to update the law to reflect changing social conditions — in particular, the recognition that children should not be denied protection simply because they are technically trespassers.

Note: The law on occupiers' liability to trespassers was subsequently placed on a statutory footing by the Occupiers' Liability Act 1984.

R v Howe [1987]

Previous decision: In DPP for Northern Ireland v Lynch [1975], the House of Lords had held that duress was available as a defence to a secondary party (an accessory) to murder.

Facts in Howe: The defendants participated in murders, claiming they acted under duress (threats from a violent gang leader). One was a principal and one was a secondary party.

Decision: The House of Lords used the Practice Statement to depart from Lynch. They held that duress is not available as a defence to murder, whether the defendant is a principal or a secondary party. The sanctity of human life means that a person should never be excused for taking an innocent life, even under threats.

Significance: This demonstrated the Practice Statement being used in the criminal law — despite the warning in the Practice Statement about the "especial need for certainty" in criminal matters. The Lords felt the moral imperative of protecting the sanctity of life outweighed the concern about certainty.

R v Jogee [2016]

Previous decision: In R v Powell; R v English [1999], the House of Lords had endorsed the principle of parasitic accessorial liability (also known as "joint enterprise"). Under this principle, if two people embarked on a joint criminal enterprise and one committed a further crime that the other foresaw as a possibility, the other was guilty as an accessory — even if they did not intend the further crime.

Facts in Jogee: Jogee and another man went to the victim's house. The other man stabbed and killed the victim. Jogee was convicted of murder on the basis that he foresaw the possibility of the stabbing.

Decision: The Supreme Court used the Practice Statement to depart from Powell and English. The Court held that the law had taken a "wrong turn" over 30 years earlier. The correct test for accessorial liability is intention (that the accessory intended to assist or encourage the crime), not mere foresight (that the accessory foresaw it might happen).

Significance: This was a landmark use of the Practice Statement that affected potentially hundreds of existing convictions. It demonstrated the Supreme Court's willingness to correct what it regarded as a fundamental error of law, even decades after the error was made.

Cases Where the Practice Statement Was NOT Used

The Practice Statement has been refused far more often than it has been applied:

• Jones v Secretary of State for Social Services [1972] — Lord Simon noted that it was too soon after the Practice Statement to start using it extensively; the House should show restraint
• R v Kansal (No. 2) [2001] — The House of Lords declined to use the Practice Statement despite acknowledging that the previous decision (R v Lambert [2001]) was probably wrong, because the issue was due to be resolved by Parliament
• R v Clegg [1995] — The Lords refused to use the Practice Statement to change the law on self-defence and murder, holding that such a change should be made by Parliament

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The Court of Appeal: Young v Bristol Aeroplane Co [1944]

The Court of Appeal does not have the benefit of the Practice Statement. It is generally bound by its own previous decisions. However, the case of Young v Bristol Aeroplane Co Ltd [1944] established three exceptions to this rule:

The Three Exceptions

1. Conflicting decisions — Where two previous Court of Appeal decisions conflict, the Court must choose which to follow and which to overrule. The Court is not bound by the decision it does not follow.