Necessity – public and private

By Shantanu Rathore , Symbiosis Law School, Noida

Editor’s note: There exist several justifications and exceptions for torts, including the defence of necessity, which is usually invoked for the tort of trespass and conversion. Welfare of the people is deemed to be the supreme law, and necessity can either be public or private. This paper analyses the evolution of the doctrine of necessity via landmark judgments and the line of distinction between necessity and private defence.


The law of torts provide many justifications or defences, for preventing any admission of liabilities on the part of tortfeasor, like private defence, volenti non fit injuria, inevitable exercise etc., and one such affirmative defence is necessity. The defence of Necessity is generally available against the intentional torts like that of trespass and conversion. It is based on maxim salus populi suprema lex, i.e. ‘the welfare of the people is the supreme law’. Necessity is primarily of two types:

1). Public Necessity;

2). Private Necessity.

Necessity, nowadays have become more kind of a risky defence, with the advent of strict liability and absolute liability, as the line is very thin between them. The few cases showing the evolution of necessity are (i) Vincent v. Lake Erie Transp. Co.[1], (ii) Ploof v. Putnam[2], we will go through the details of these cases later in this research. It is more than ever confused with self-defence / private defence of self and others as they have many elements in common.


Necessity as a defence is defined under section 81 in Indian Penal Code as:

“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.”

The explanation of the same is that 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. Necessity may justify physical harm caused[3], but cannot be used as a defence when there is human life involved such as if there is incriminating throwing of people to save the sinking boat[4], but if the goods are thrown overboard the same will be justified[5].

Tort been mainly concerned with compensation and necessity justifies the unlawful act and hence, either lessens or mitigate the liability. The defence of necessity requires the defendant to prove on his part that the unlawful act committed by him satisfies the following elements:

  • It was not a result of his own negligence;
  • S/he acted to avoid a significant risk of harm;
  • No other alternative lawful means were available;
  • Harm avoided was greater than the harm which resulted due to his act;
  • The harm was imminent and the act was reasonable.

These elements made it a circumstantial defence and also show the principle it is founded i.e. the greater good of all by saying that the highest value is not adherence to law but to achieve social welfare.

Now the basic difference between necessity and other defences like private defence is mainly the act of plaintiff, unlike private defence, the damage inflicted on the plaintiff was not provoked by any actual or threatened illegal wrong on the plaintiff’s part, and that the defendant’s action may be entirely for the good of other people and not necessarily for the protection of himself or his property. That is the plaintiff is free from any wrong-doing. As said before, there are 2 types necessity they are (a) Public Necessity, and (b) Private Necessity; now we will look into each one of them.

Public Necessity

“Public Necessity” occurs when a defendant takes someone else’s property in order to prevent damage to the community as a whole.  Often, the defendant must be a public official in order to claim the defence of public necessity and serves as an absolute defence. Public Necessity over-shadows private rights[6], but just in order to save a greater harm to society at large. So, it justifies the demolishing of houses on fire to prevent fire from expanding[7], good cast overboard from a ship5.

Private Necessity

Private necessity rather than arising out for general public arises for self interest. S/He (defendant) may interfere with someone’s (plaintiff) property in an emergency to protect an interest of his own. Private necessity does not serve as an absolute defence to liability. If for e.g. A commits a trespass on the property of B and in the same causes some damage to B’s property, A if successfully pleads private necessity will be liable to pay the compensation to restore the harm but not punitive or nominal damages. But if B trying to force out A out of his property commits a tort, while B is claiming private necessity, A will be liable for the torts committed[8].

The principle been “necessitas inducit privilegium quod jura private”, meaning ‘Necessity induces a privilege because of a private right’. The mentioned maxim makes it quite clear that rather been a defence its more kind of a privilege enjoyed by persons. The defence founds its way into the present legal system mainly through Vincent v. Lake Erie Transp. Co.[9], which just evolved the principle that was in a way already established by Ploof v. Putnam[10], but the later didn’t made, who was at fault or in more clear terms who should pay whom, which the Vincent case did.

In Vincent v. Lake Erie Transp. Co., the jest of the matter was that a ship was already tied to a dock, when a storm hit the region, due to which the ship and the deck was continuously colliding and the dock owner filed a suit for compensation against the ship owner’s, in the proceedings that followed, it was held that the defence of private necessity applies but the damage caused to one by the act of the other needs to compensated which was left in Ploof v. Putnam. But, the principle that one, who is under the ambit of private necessity can’t be forced to move out of someone’s property comes from Ploof v. Putnam2, in which the weather conditions were not good and a private sloop tied itself to a private dock, but their ropes were released in the middle of the storm and as a result they were held liable as the sloop was under private necessity. Hence, on a deep analysis of both the cases it comes out necessity in a way involves conflict of interests and hence as said in Olga Tellis v. Bombay Municipal Corporation[11], “necessity is a plausible defence, which enables a person to escape liability………. hence, … a balance has to be struck between competing sets of values”.


Necessity as a defence has been used in several cases, tortuous as well as criminal. Necessity, generally, have not been able to justify criminal acts such as that of murder, even that of stealing food on record of his ultimate hunger as stated in the obiter by Lord Coleridge CJ in the famous case or the founding case of necessity in English law viz. is R v Dudley and Stephens[12] stated:

“Who is to be the judge of this sort of necessity? By what measure is the comparative value of lives to be measured? Is it to be strength, or intellect, or what? It is plain that the principle leaves to him who is to profit by it to determine the necessity which will justify him in deliberately taking another’s life to save his own. In [the present case] the weakest, the youngest, the most unresisting life was chosen. Was it more necessary to kill him than one of the grown men? The answer be, No.”

This case made necessity to come as a good rather an evil to justify everyone’s lust and prevented a chaotic state that could have prevailed if this would not have been the case. The same was said by Lord Denning MR in slightly different words but inferring the same in Southwark LBC v Williams[13] and many have even called necessity a mask for anarchy. Same opinions have been framed by various Indian judges and scholars as stated in Olga Tellis v. Bombay Municipal Corporation11. On the question of economic necessity the Honourable Supreme Court of India (SC) in various cases have justified the use of pavement to be used as a trade place but have quashed any right such as to occupy a particular place[14]. However, in a case of removal of hutment dwellers SC held that who were already there before the cut off date fixed by the court cannot be removed until provided alternative site for re-settlement[15]. In both the judgements, the background of the decisions was the necessity of them, as their livelihood depends on the same, but this argument can’t be made if the person after committing theft or any offence for that matter pleads necessity for livelihood, as it will lead to chaos and unruliness, which the law is required to keep in check.

Public Necessity is said to be an absolute defence but it from the eyes of justice and equality don’t seems fair that a person bears damage but he cannot recover any compensation under law of torts, which was the prime motive of torts i.e. to provide relief to the suffered. In Surocco v. Geary7, the main motive of torts is left out and Surocco suffers damage and the court instead of awarding any damages held that there was no wrong committed as it was a matter of public necessity and private individual good sometimes needs to be sacrificed for greater social good, but then in Wegner v. Milwaukee Mutual Ins. Co.[16], the court held that if an individual suffers loss for the benefit of the public than it is the duty (reciprocative) of the public through taxes to compensate his losses, not a burden on the individual for his sacrifice. Now, the decision of providing damages is now a matter of public policy and generally, nowadays compensation is awarded.

R v. Dudley and Stephens[17]

The discussion of private necessity cannot be completed without this case of English, belonging to Victorian Era Britain. The facts of the case are as follows:

  • The defendants and a cabin boy were cast adrift in a boat following a shipwreck.
  • The defendants agreed that as the cabin boy was already weak, and looked likely to die soon, they would kill him and eat him for as long as they could,
  • In the hope that they would be rescued before they themselves died of starvation.
  • A few days after the killing they were rescued and then charged with murder.

The defendants plead the defence of necessity and customs of sea. They plead that it was necessary for them to kill the cabin boy and eat him in order to survive of them. They plead necessity on the grounds that they saved a greater harm i.e. that of all of them by doing a smaller harm i.e. killing of the weak cabin boy and eating him, in order to survive, but the same cannot be made a ground for necessity; otherwise it would just lead to lawlessness, barbarianism and anarchy.

The case makes the defence of necessity a narrow one and also a good one from social as well as ethical point of view, even from been of Victorian Era, it still holds true.


Necessity embodies elasticity to law and punishments, and a humane touch; it provides a safe-valve for citizens to break the law, in circumstances of extreme need and the breaking of law in such a situation is legalised, so that such an act is penalised. Necessity as a defence is new and evolving, in relation to other defences like act of god etc, which have been fully debated and evolved over period of time. Necessity needs to be debated and its complexities sorted out. Been a new defence, it has many flaws and dimensions unexplored. Necessity is a defence which involve case by case analysis and hence, does not have a strict rule of application and depends on circumstances. It’s in the womb of future, how necessity would be evolved in upcoming time, in between the matters of strict liability and absolute liability.

Edited by Neerja Gurnani

[1] Vincent v. Lake Erie Transp. Co., 109 Minn. 456, 124 N.W. 221 (1910).

[2] Ploof v. Putnam, 71A. 188 (Vt. 1908).

[3] Gopal Naidu v. Emperor (AIR 1923 Mad FB 523).

[4] United States v. Holmes [1842]  (Fc 360, No 15383, CC- Pennsylvania, US).

[5] South Port Corporation v. Esso Petroleum Co., (1952) 2 All ER 1204 (QBD) affirmed 1956 AC 218 (HL).

[6] Mc Phail v. Persons Unknown, (1973) 3 All ER 393 (CA).

[7] Surocco v. Geary, 3 Cal. 69, 1853 Cal.

[8] Gilbert v. Stone, 8 Eng. Rep. 539 ( K.B.) 1648)

[9] Vincent v. Lake Erie Transp. Co., 109 Minn. 456, 124 N.W. 221 (1910).

[10] Ploof v. Putnam, 71A. 188 (Vt. 1908).

[11] Olga Tellis v. Bombay Municipal Corporation,  (1985) 3 SCC 545,

[12] R v. Dudley and Stephens (1884) 14 QBD 273.

[13] London Borough of Southwark v. Williams (1971) 2 All ER 175 (191) 2 WLR 467.

[14] AIR 1989 SC 1988, p. 1996.

[15] AIR 1989 SC 1988, p. 1997.

[16] Wegner v. Milwaukee Mutual Ins. Co., 479 N.W. 2d 38 (Minn 991).

[17] R v Dudley and Stephens (1884) 14 QBD 273.

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