This article has been written by Tanya Gupta, a student pursuing BA LLB from Ideal Institute of Management and Technology and School of Law, affiliated to Guru Gobind Singh Indraprastha University, Delhi. This article focuses on the principle of necessity and related case laws.


Is every act done with the knowledge considered as an offence? An act done with the knowledge but without any criminal intention is not considered as an offence. If the person, doing an act in good faith to prevent or avoid greater harm, then it is not said to be an offence. There are various General defences available to the person.

Necessity: As a Defence

  • Necessity in legal context involves the judgement that the evil of obeying the letter of the law is socially greater in the particular circumstances than the evil of breaking it. As a defence law permits the use of reasonable force to protect one person or property but when there is a situation when the person has to choose between to save the life of a person or to save the property of the person then definitely the person chooses to protect the life of a person first. If the person uses the force which is unnecessary to self -defence then the private defence is not available to that person. This exception is based on the maxim ”salus populi suprema lex”, means that the welfare of the people is the supreme law. If a person chooses between the welfare of the community and individual welfare, then he must first choose the welfare of the community. As in order to prevent a greater harm, slight harm is permitted.

Let’s discuss the concept with an illustration, 

The motorman came to know that there was a problem in a train because it became uncontrollable and there were two tracks before him, the first track on which there were two persons standing on a track and on the second track there were so many people standing on it. Then he chooses, the first track to move the train further. He is not guilty of this because the principle of necessity would be applied. As the action of the motorman prevents the greater ham and he chooses first track instead of second.

Necessity: In Indian Penal Code, 1860

As we all know, that necessity is criminal as well as a civil offence. But in reality, it is not an offence it is considered as a defense. In order to prevent greater harmless harm is permitted. Section 81, Indian Penal Code, 1860 discusses the principle of necessity under Chapter IV, General Exceptions.

Act likely to cause harm, but done without criminal intent, and to prevent other harm.—Nothing is an offence merely by reason of its being done with the knowledge that it is likely to cause harm, if it be done without any criminal intention to cause harm, and in good faith for the purpose of preventing or avoiding other harm to person or property.

 Explanation—It is a question of fact in such a case whether the harm to be prevented or avoided was of such a nature and so imminent as to justify or excuse the risk of doing the act with the knowledge that it was likely to cause harm.

  • It embodies the principle that where the accused chooses lesser evil, in order to avert the bigger. The genesis of this principle emanates from two maxims: “quod necessitas non habet legem” (necessity knows no law) and “necessitas vincit legem (necessity overcome the law).

Let’s discuss this concept with an illustration,

A, in a great fire, pulls down houses in order to prevent the conflagration from spreading. He does this with the intention in good faith of saving human life or property. Here, if it is found that the harm to be prevented was of such a nature and so imminent as to excuse A’s act, A is not guilty of an offence.

In the above illustration, pulling down a house to prevent the fire from spreading, where pulling down a house is an offence per se. But when it is not done with the intention of destroying the neighbour house but only to prevent a greater harm, then the principle of necessity would be applied.

Essentials: Necessity

  1. The damage caused was less than that would have occurred otherwise. 
  2. the person reasonably believed that his actions were necessary to prevent imminent harm. 
  3.  there was no practical alternative available for avoiding the harm.
  4.  the person died not to cause the threat of harm in the first place

Restrictions: Necessity

 There are some limitations of necessity following as:

  1. In the first place, the defence will not succeed if the necessity is arising out of the negligence act of the defendant himself. 
  2.  there must be a real or imminent danger to the person or property.
  3.   Distinction is maintained between the safety of human life and the safety of property for obvious reasons.

Case Laws: Necessity

Carter v. Thomas, 1976

FACTS: fire accident occurred in the premises of plaintiff where the fire workmen reached and tried to extinguish the fire and at the same time defendant also entered into the plaintiff’s premises in order to extinguish the fire by pouring the water by bucket and at last the fire extinguished.

The plaintiff filed a suit against the defendant that he entered into the premises of the plaintiff without his permission and made a contention that he was liable for trespass.

The defendant took the defence of necessity because it was necessary to extinguish the fire.

OBSERVATION AND HELD: Court observed that in the plaintiff’s premises the fire workmen were already reached and extinguish the fire. So, there was no need for the defendant and he was also entered into the plaintiff ’s premises without his permission. Court held the defendant liable for trespass. 

Olga Tellis v. Bombay Municipal Corporation, 1985 SCC 545 

The Apex Court held that ”under the law of torts necessity is a plausible defence, which enables a person to escape liability on the ground that the act complained of is necessary to prevent a greater harm, inter alia, to himself. So, the trespass on some property cannot be justified always on the basis of necessity.

The defence is available if the act complained of was reasonably demanded by the danger or emergency.”

Dhania Daji, (1868) 5 BHC (CrC) 59

FACTS: a person placed poison in his toddy pots, knowing that if taken by a human being it would cause injury, but with the intention of thereby detecting an unknown thief who was in the habit of stealing the toddy from his pots. The toddy was drunk and caused injury to some soldiers who purchased it from an unknown vendor.

 HELD: It was held by the Court that the person was guilty under section 328 of Indian penal code, 1860(causing hurt by means of poison or any, intoxicating or unwholesome drug or other thing with intent to commit an offence) and that section 81 did not apply.


This defence is based on the maxim “salus populi suprema lex’’ which means, the welfare of people is the supreme law. By this maxim, injury to some person is possible for the welfare of the majority of the society. For this, there should be the welfare of the maximum person and injury to the minimum person. It is pertinent to note that the principle of necessity does not specifically discuss the ‘greater evil’ or ‘lesser evil’, it in effect deals with the case of ‘lesser evil’.

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