the defence of necessity

The controversial defence in the law of tort: What is necessity?

Talk of necessity, in law reminds one of jurisprudence, a subject in law school. While studying the philosophy of law, a hypothetical case that discusses the defence of necessity among other things is discussed. In that case, a group of men on an adventure were stuck in a cave after it caved in on them. For many days, they stayed without food and decided to eat one of them. They cast lots and it fell on one of them. He would be eaten. Indeed, they slaughtered him, and at him. A few days later, they were rescued. When it was known that they had eaten a member of their group, they were prosecuted for murder.

In their defence, they pleaded necessity. They said they would have starved if they hadn’t eaten their colleague. The bench had diverse opinions on whether the defence was sustainable. Some agreed, others did not.

Presently, there is no defence of necessity to a murder charge. Neither is it there for a charge of cannibalism. Morals seem to be the basis for such a standard.

Necessity is different from self-defence. In self-defence, the accused avers that the victim would have harmed him if he didn’t harm in. Necessity is also different from defence of personal property. In defence of personal property, the accused avers that the victim would have destroyed his property if he didn’t inflict harm on him.

The line that cuts across in the three defences is that the magnitude must be proportional. For example, when Agrace is attacked with a broom, she cannot in self-defence attack her assailant with an axe or a machete. If Agrace catches someone trying to steal her yams, she may not scare the thief away by setting him on fire.

Necessity is a defence in the law of tort. It is used to defend oneself from trespass and conversion. Trespass is an unlawful intrusion that interferes with one’s person or property. Conversion is any unauthorized act that deprives an owner of personal property without his or her consent.

The defence of necessity is used to concede that the defendant had to take or use property belonging to the plaintiff to prevent greater harm to the defendant, the community, or the defendant’s property. The defence is also used after the plaintiff brings a case that the defendant damaged or destroyed their property while using it, and the plaintiff seeks compensation in the form of damages for the loss of her property.

For a defence of necessity to be sustainable, the damage to the property the defendant temporarily took without authorisation must be less than the damage that would have occurred if the defendant had not used the property. If the amount of damage is roughly equal, then the necessity of defence may not apply.

Necessity is typically divided into two categories: public necessity and private necessity.

Public Necessity

“Public necessity” occurs when a defendant takes someone else’s property to prevent damage to the community.  Often, the defendant must be a public official to claim the defence of public necessity.

One example of public necessity appears in Surocco V Geary, a California case decided in 1853. Before the case was decided, wild fires had swept through San Francisco and had destroyed a lot property. Surocco lived in a house which stood in the path of fire, and on that fateful day, he was running to his house to save some of his possessions before the fire could consume everything. Before he got to his house, and before he could save anything, Geary, the mayor of San Francisco ordered the fire department to demolish Surocco’s house so that the fire does not spread to other properties in the neighbourhood. Using dynamite, Surocco’s house was levelled.  Surocco sued Geary, claiming that if Geary had not ordered the fire department to blow up his house, Surocco could have saved more of his personal possessions. The court, however, found that the public necessity defence applied because the damage to the city would have been far worse if Geary had not given the order to have Surocco’s house demolished.

Public necessity is usually an absolute defence. This means that if the court buys it, then the defendant is not liable to the plaintiff for any damages.

Private Necessity

The defence of “private necessity” applies when a defendant takes the plaintiff’s property and uses it to prevent greater harm to their own private property. Although causing less damage to someone else’s property to prevent greater damage to one’s own property is often the wisest course of action, defendants who demonstrate that private necessity existed must pay actual damages to cover the damage caused by their use of the plaintiff’s property. However, in such cases, defendants are not liable for punitive damages or nominal damages.

This defence was applied in the 1910 case of Vincent V Lake Erie Transportation Company. In that case, employees were unloading a steam ship owned by Lake Erie which was tied to Vincent’s dock. While unloading, a storm came up and instead of cutting the steam ship free, the employees tied and fastened it further onto Vincent’s dock. The storm hit the ship causing it to ram into the dock this causing. If the employees had cut the ship loose, it would have sunk in the storm.

On hearing the case, court held that the defence of private necessity applied. However, Lake Erie was found to be liable to Vincent in damages to repair his dock.

A successful plea of private necessity earns a defendant a right to damages if they suffer damage from the plaintiff. For example, a sky diver who lands in a farmer’s garden of tomatoes instead of landing in a turbulent river nearby is liable to the farmer for the damage caused to the farmer’s garden. However, if the farmer hit the sky diver with his hoe for trampling on his tomatoes, then the farmer may also be liable in damages to the sky diver for the battery. This however does not preclude the farmer from pleading the defence of defence of personal property. Such are the complexities of civil litigation.

From different facts, different defences can be adopted. Call us or text us or email us any time, any day and we shall advise you, subject to your facts.


This article appears in our law newsletter Vol 1 Issue 2 of January 19th  2018. To receive The Deuteronomy in real time, click HERE

The law permits sharing.

Leave a Reply

Your email address will not be published. Required fields are marked *