Necessity as a defence for tortuous liability


When an action is brought by a plaintiff against the defendant for a specific wrong and satisfies existence of all the essentials for that wrong, the defendant would be held liable for the same. However, the defendant can escape from such a situation by using certain defences which are specific to each wrong. Therefore, General defences are a set of excuses or ways which the defendant may use in order to avoid such liability. Some of the General defences used may be a necessity, Act of God, Volenti non-fit injuria, Plaintiff the wrongdoer, Inevitable accidents, Private defences, Mistake, Statutory authority.


‘Necessity’ as defined by the Black’s Law Dictionary means ‘Controlling force’; ‘an irresistible compulsion’; ‘a power or impulse so great that it admits no choice of conduct’. The general rule is that no person, while exercising his rights, can infringe any other person’s rights or freedoms, except for a situation where the person may be forced to act in such a way that it might result in a legal injury to someone. Thus, the defence of Necessity recognises that if a person, in order to avoid greater harm, may cause damage to other person’s rights and he is excused from any liability for that damage.

This is based on the concept of ‘nessitas inducit previlegium quod jura privata’ from Latin common law. This implies that, because of the private right,’ necessity induces privilege’. Where the danger of harm to a person or community is apparently and fairly greater than the harm to the land, the court will grant this right to trespass. It is important to draw a difference between necessity and private defence. The major difference between the two is that in necessity the damage is caused to an innocent person while on the other hand in private defence the damage is inflicted upon the plaintiff, who himself is the wrongdoer. Necessity is also distinguishable from an inevitable accident in a way that an act in necessity is performed with the backing of full intention while in case of an inevitable accident, the damage occurs in spite of taking best efforts to avoid it.

An instance for Necessity is in the Mouse’s Case [1609] 12 Rep. 63, throwing goods overboard to lighten the ship was allowed in order to save the ship and the people on board from sinking. In the same way, taking down of a house under fire to prevent a further fire spreading; doctor performing surgery to an unconscious person for the sake of saving his life; saving a drowning person are allowed.  Forcible feeding of a hunger strike inmate to save her was deemed a good defence to an action for battery in Leigh v. Gladstone.

In Cope v. Sharpe,5 the defendant entered the plaintiff’s land to prevent the spread of fire to the adjoining land over which the defendant’s master had the shooting rights. Since the defendant’s act was considered to be reasonably necessary to save the game from real and imminent danger, it was held that the defendant was not liable for trespass.


For example, A entered B’s property, seeing that C, the daughter of B, had caught into the fire and was burning. A must break down the fencing to reach the territory. A rescued C, but B lodged an infringement case against A. In the aforementioned case, A would not be held liable for any kind of trespass as he can take the defence of necessity and thus would not be responsible to provide for any damages.


The necessity defence applies to a situation where a person was forced to act in a wrongful manner so as to prevent greater harm that could occur to the person or any other person or any property or to the community at large. However, in order to apply this defence certain essentials are required to be met.

  1. The damage inflicted due to the act of necessity should be less than the damage that could have occurred in original circumstances.
  2. The person performing such act was reasonable in his belief that the act was necessary to avoid greater damages.
  3. No practical alternative should be available to avoid the damage.
  4. The person/ doer were not, in the first place, the cause of all the damages.



Private necessity normally requires trespassing or interfering with a person’s property to protect him or his property. Usually, as long as the emergency is still underway, one has the right to continue trespassing or using the property of the person.

The defence of private necessity is a partial defence available to the defendant, meaning that the defendant who commits any trespass and claims the defence of personal necessity must still pay for the damages caused by his trespass to the plaintiff. For instance, in the case of Vincent v. Lake Erie Transportation Co., the defendant was emptying his cargo from the steamship operated by the defendant at the dock of the plaintiff. The defendant was unable to leave the port safely due to a violent storm, so he bound the ship to the dockyard. A sudden wind threw the ship against the dock, causing the dock to sustain severe damages. It was concluded that a defence of private necessity could require one to take or injure the property of another, but compensation is required. The defendant purposely kept the ship bound to the dock; otherwise, the ship would have been lost, resulting in much greater damage.


Public need means any action taken by public authorities/officials or private persons to prevent a public tragedy that has the potential to affect the general public. This is enforced when an individual commits some trespass to protect a larger group.

Public Necessity is an absolute defence which means that the persons who have trespassed are not required to pay any compensation to the owner of the property. Generally, public employees like firefighters, police, and army personnel claim public necessity.

CHRIST UNIVERSITY 1st year student

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