Necessity as a Defence under Law of Torts

Introduction and Meaning of Necessity

Necessity, as defined by the Oxford English Dictionary, refers to something essential or unavoidable. In legal terms, necessity serves as a defence to protect individuals who commit an act that would otherwise be considered a tort, but is justified due to urgent and unavoidable circumstances. This doctrine has its origins in justifying the invasion of property during emergencies, such as saving properties from fire during wartime.

Necessity is primarily used as a defence in cases of trespass, but it must be for the greater public good or public interest. Private necessity generally does not qualify as a valid defence, except in certain exceptional cases. A defendant who uses reasonable force against an innocent person or property to avert imminent danger for the public good may invoke the defence of necessity.

For example, in Leigh v. Gladstone, a woman on a hunger strike was forcibly fed by authorities. The court upheld the defence of necessity against a claim of battery. Similarly, in Cope v. Sharpe, the defendant entered the plaintiff’s land to prevent a fire from spreading, and the defence of necessity was accepted as the act was to avert a greater harm.

Difference Between Self-Defence and Necessity

While self-defence and necessity may seem similar, they differ significantly. In self-defence, the individual acts to protect themselves from a direct threat, often harming the wrongdoer. In contrast, necessity involves harming an innocent party to prevent a greater harm.

For instance, in Ploof v. Putnam, the plaintiff tied his boat to the defendant’s dock to escape a storm. When the defendant’s servant untied the boat, causing it to be destroyed, the court ruled in favor of the plaintiff, recognizing that the trespass was necessary. Here, the plaintiff did not intend to harm the defendant, unlike in self-defence cases, where the harm is directed at a perceived aggressor.

In People v. La Voie, the defendant shot a man who aggressively approached him after a minor car collision. The court upheld the defendant’s action as self-defence, as he believed he was in imminent danger. This contrasts with necessity, where the person causing harm knows the other party is innocent but acts to prevent a larger danger. Additionally, necessity generally involves less force than self-defence, making it the "lesser of two evils."

Contrast Between Inevitable Accident and Necessity

The defence of inevitable accident also intersects with necessity, but the key difference lies in intent. In cases of necessity, the harm is intentional and justified by the circumstances, while in inevitable accidents, the harm occurs despite efforts to prevent it.

For example, in Stanley v. Powell, the defendant unintentionally injured the plaintiff when a shot ricocheted off a tree during a pheasant shoot. The court ruled this as an inevitable accident, as there was no intention to cause harm. In contrast, necessity requires a deliberate action, justified by the need to prevent a greater harm.

Necessity in Medicine

Necessity also plays a significant role in medical law. Courts have ruled that medical treatment provided to an incapable person can be justified under the defence of necessity if it prevents a greater harm, even if it might otherwise be considered a tort.

In Re A (Children) (Conjoined Twins: Surgical Separation), the court allowed the separation of conjoined twins, even though it meant that the weaker twin would likely die. The surgery was necessary to save at least one of the twins, and had this case been under tort law, the defence of necessity would still apply.

Conclusion

The defence of necessity under tort law is essential for justice. Without it, individuals who act under duress to prevent greater harm could be unfairly held liable. The doctrine of necessity ensures that the law remains just and flexible, allowing courts to account for the complexities of real-world situations. It underscores the primary function of the legal system: to administer justice based on the specific circumstances of each case.