Necessity

Introduction

Sometimes a person may intentionally cause damage in order to prevent a greater harm or danger. In such situations, the law may excuse the act if it was done out of necessity.

The defence of necessity allows a person to avoid liability when their action was taken to protect life, property, or public safety in an emergency situation.

Meaning / Definition

The defence of necessity is based on the maxim “Necessitas inducit privilegium quod jura privata”, which means necessity creates a privilege that may override private rights.

It is also supported by the maxim “Salus populi est suprema lex”, meaning the welfare of the people is the supreme law.

Under this defence, a person may intentionally interfere with another person's rights if the act is done to prevent greater damage or danger.

Modes or Types

Necessity to Exercise Legal Authority

Sometimes a person may act out of necessity while exercising authority granted by law.

Example:
A police officer may restrict the movement of a drunken person if that person poses a danger to the public.

Necessity to Avoid Greater Harm

An act may be justified if it is done to prevent a more serious injury or damage.

In such situations, causing minor harm to avoid a greater disaster may be legally justified.

Necessity in Public Interest

Necessity may also apply when an action is taken for the larger interest or safety of the public.

The law recognises that protecting public safety and welfare may sometimes require temporary interference with private rights.

Limits of the Defence

The defence of necessity is not unlimited. It will fail if:

• The act was unreasonable or unnecessary.
• The danger was not real or immediate.
• The defendant created the danger themselves.

For example, placing live electric wires around property to prevent trespass without proper warning would not be justified under necessity because it creates serious risk to others.

Important Case Law

Cope v. Sharpe

A fire broke out on land owned by A. While A’s servants were trying to extinguish the fire, a gamekeeper with shooting rights over the land burned strips of heather to stop the fire from spreading toward nesting birds.

A sued the gamekeeper for trespass. The court held that the gamekeeper was not liable, because the act was done to prevent immediate and greater harm, and therefore the defence of necessity applied.

Practical Example

Suppose a person breaks open a locked door to rescue a child trapped inside a burning house.

Although breaking the door may normally amount to trespass or damage to property, the act would be justified because it was done to save human life, which is a greater interest.

Summary

• Necessity is a defence in tort law where harm is caused to prevent greater harm.
• It is based on the maxim “Salus populi est suprema lex” meaning the welfare of the people is the supreme law.
• The defence applies when an act is done to exercise legal authority, avoid greater harm, or protect public interest.
• The danger must be real and immediate.
• The act must be reasonable and proportionate (not excessive).
• If the act is unnecessary or reckless, the defence of necessity will not apply.