Necessity: Wikis


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From Wikipedia, the free encyclopedia

In U.S. criminal law, necessity may be either a possible justification or an exculpation for breaking the law. Except for a few statutory exemptions and in some medical cases [1] there is no corresponding defense in English law.[2] Defendants seeking to rely on this defense argue that they should not be held liable for their actions as a crime because their conduct was necessary to prevent some greater harm and when that conduct is not excused under some other more specific provision of law such as self defense.

For example, a drunk driver might contend that he drove his car to get away from a kidnap (cf. North by Northwest). Most common law and civil law jurisdictions recognize this defense, but only under limited circumstances. Generally, the defendant must affirmatively show (i.e., introduce some evidence) that (a) the harm he sought to avoid outweighs the danger of the prohibited conduct he is charged with; (b) he had no reasonable alternative; (c) he ceased to engage in the prohibited conduct as soon as the danger passed; and (d) he did not himself create the danger he sought to avoid. Thus, with the "drunk driver" example cited above, the necessity defense will not be recognized if the defendant drove further than was reasonably necessary to get away from the kidnapper, or if some other reasonable alternative was available to him. However case law suggests necessity is narrowed to medical cases.


General discussion

As a matter of political expediency, states usually allow some classes of person to be excused from liability when they are engaged in socially useful functions but intentionally cause injury, loss or damage. For example, the fire services and other civil defence organizations have a general duty to keep the community safe from harm. If a fire or flood is threatening to spread out of control, it may be reasonably necessary to destroy other property to form a fire break, or to trespass on land to throw up mounds of earth to prevent the water from spreading. These examples have the common feature of individuals intentionally breaking the law because they believe it to be urgently necessary to protect others from harm, but some states distinguish between a response to a crisis arising from an entirely natural cause (an inanimate force of nature), e.g. a fire from a lightning strike or rain from a storm, and a response to an entirely human crisis. Thus, parents who lack the financial means to feed their children cannot use necessity as a defense if they steal food. The existence of welfare benefits and strategies other than self-help defeat the claim of an urgent necessity that cannot be avoided in any way other than by breaking the law. Further, some states apply a test of proportionality. So the defense would only be allowed where the degree of harm actually caused was a reasonably proportionate response to the degree of harm threatened. This is a legal form of Cost-benefit analysis.

Specific jurisdictions



In English law, the defence of necessity recognises that there may be situations of such an overwhelming urgency, that a person must be allowed to respond by breaking the law. There have been very few cases in which the defence has succeeded but the Crown Prosecution Service tends to exercise a discretion not to prosecute those cases where it believes that the potential defendants have acted reasonably in all the circumstances.


Canadian criminal law allows for a common law defence of necessity. The leading case for the defence is Perka v. The Queen [1984] 2 S.C.R. 232 in which Dickson J. described the rationale for the defence as a recognition that:

a liberal and humane criminal law cannot hold people to the strict obedience of laws in emergency situations where normal human instincts, whether of self-preservation or of altruism, overwhelmingly impel disobedience.

However, it must be "strictly controlled and scrupulously limited." and can only be applied in the strictest of situations where true "involuntariness" is found. Three elements are required for a successful defence :

  1. the accused must be in imminent peril or danger
  2. the accused must have had no reasonable legal alternative to the course of action he or she undertook
  3. the harm inflicted by the accused must be proportional to the harm avoided by the accused

Each element must be proven on an objective standard. The peril or danger must be more than just foreseeable or likely. It must be near and unavoidable.

At a minimum the situation must be so emergent and the peril must be so pressing that normal human instincts cry out for action and make a counsel of patience unreasonable.

With regard to the second element, if there was a realistic or objectively reasonable legal alternative to breaking the law, then there can be no finding of necessity. Regarding the third element requiring proportionality, the harm avoided must be at least comparable to the harm inflicted.

In R. v. Latimer (2001), the Supreme Court of Canada affirmed that the defense of necessity is not available to a defendant when (1)the killing occurred when there was no imminent danger to either the defendant or the victim, (2) reasonable legal alternatives are available besides killing, and (3) the harm inflicted is not in proportion to the harm avoided.

United States

Model Penal Code

The Model Penal Code of the American Law Institute adopts a belief-based "choice-of-evils" theory of necessity in Section 3.02 - "Justification Generally: Choice of Evils":

§ 3.02 (1) Conduct which the actor believes to be necessary to avoid a harm or evil to himself or another is justifiable . . . .

The use of the defense is subject to certain limitations, notably: that the harm to be prevented be greater than that caused (§ 3.02(1)(a)); that it not be excluded by the law (§ 3.02(1)(b)) or a plain legislative purpose (§ 3.02(1)(c)); and that the actor not have recklessly or negligently have created the emergency, where the crime charged requires recklessness or negligence (§ 3.02(2)).

Note that the Model Penal Code is not the law of any state, though many states have adopted some of its rationale or provisions.

New York State

The Penal Law of the State of New York collapses justification and necessity into a single article. Article 35 - "Defense of Justification" comprises sections 35.05 through 35.30 of the Penal Law. The general provision relating to necessity, section 35.05, provides:

§ 35.05 Justification; generally. Unless otherwise limited by the ensuing provisions of this article defining justifiable use of physical force, conduct which would otherwise constitute an offense is justifiable and not criminal when: 1. Such conduct is required or authorized by law or by a judicial decree, or is performed by a public servant in the reasonable exercise of his official powers, duties or functions; or

2. Such conduct is necessary as an emergency measure to avoid an imminent public or private injury which is about to occur by reason of a situation occasioned or developed through no fault of the actor, and which is of such gravity that, according to ordinary standards of intelligence and morality, the desirability and urgency of avoiding such injury clearly outweigh the desirability of avoiding the injury sought to be prevented by the statute defining the offense in issue. The necessity and justifiability of such conduct may not rest upon considerations pertaining only to the morality and advisability of the statute, either in its general application or with respect to its application to a particular class of cases arising thereunder. Whenever evidence relating to the defense of justification under this subdivision is offered by the defendant, the court shall rule as a matter of law whether the claimed facts and circumstances would, if established, constitute a defense.

Under the "choice-of-evils" theory of section 35.05, it is a question of fact for the criminal jury whether the conduct was justified under the circumstances. See People of the State of New York v. Maher, 79 N.Y.2d 978 (1992). As discussed in People of the State of New York v. Gray, 150 Misc. 2d 852 (N.Y. Co. 1991), the defendant is generally held to a "reasonableness" standard--the question is whether a reasonable person in the defendant's position would have reached the conclusion that the relevant conduct was necessary. It is not necessary that the defendant actually avert a greater harm, just that his belief be reasonable. As the court observed:

To apply a strict liability standard in evaluating the other elements of this defense, however, and to find that only those actors who have actually averted a greater harm may avail themselves of the defense, is inconsistent with the law of justification in New York, as well as necessity's basic purpose to promote societal interests.

However, the defendant is subject to strict liability as to which harm is greater. For example, a defendant cannot choose to value property over life.

Similarly, when using physical force in defense of a person, the focus of the defense is not on whether the actor was in fact correct that his conduct was necessary to prevent harm, but whether that belief was reasonable. Section 35.15 (1) provides in relevant part:

1. A person may, subject to the provisions of subdivision two, use physical force upon another person when and to the extent he reasonably believes such to be necessary to defend himself or a third person from what he reasonably believes to be the use or imminent use of unlawful physical force by such other person . . . .

Thus, with respect to the example given above, the actor would, provided his belief was reasonable, be entitled to have a defense of justification presented to a jury.

It is important to distinguish between the defense of justification/necessity under Article 35 and the law of citizen's arrest. In general, to use physical force a private citizen must in fact be correct that a person has committed an offence, while a police officer must only have a reasonable belief.


The Kansas Supreme Court has ruled that the necessity defense may not be used when the harm the defendant claims to be avoiding through his actions was legal, while the action undertaken to prevent it was illegal.[3] This question became an issue in the 2010 trial of Scott Roeder for the murder of abortion provider George Tiller.[4] Judge Warren Wilbert refused to allow the defense to present a plea of necessity, but did allow them to present a case for voluntary manslaughter on the grounds that the defendant sincerely believed that he was comitting a crime to prevent a greater evil.[5]


  • Christie, The Defense of Necessity Considered from the Legal and Moral Points of View, (1999) Vol. 48 Duke Law Journal, 975.
  • Fuller, Lon L. The Case of the Speluncean Explorers, (1949) Vol. 62, No. 4 Harvard Law Review [1] and The Case of the Speluncean Explorers: A Fiftieth Anniversary Symposium, (1999) 12 Harvard Law Review 1834.
  • Herman, United States v. Oakland Cannabis Buyer's Cooperative. Whatever Happened to Federalism? (2002) Vol. 95, No. 1 The Journal of Criminal Law and Criminology, 121.
  • Travis, M. The Compulsion Element in a Defence of Necessity (2000) [2]
  1. ^ See Re A (Conjoined Twins: Surgical Separation) [2001] Fam 147
  2. ^ See R v Dudley and Stephens [1884] 14 QBD 273 and R v Howe [1987] 1 AC 417
  3. ^ Anti-abortion activist can't use 'necessity defense' in slaying .
  4. ^ Allowing a manslaughter defence brings risk of anarchy , The Independent, Jan. 13, 2010.
  5. ^ Allowing a manslaughter defence brings risk of anarchy , The Independent, Jan. 13, 2010.


Up to date as of January 14, 2010

From Wikiquote

Necessity is stronger far than art. ~ Aeschylus

This page is for quotations on the theme of Necessity, and "the Necessary".


It is not necessary for the public to know whether I am joking or whether I am serious, just as it is not necessary for me to know it myself. ~ Salvador Dalí
  • Necessity is stronger far than art.
  • Wherever it is impossible for us to recognize the law of necessity, we believe we are free.
    • Wo wir unfähig sind, die Gesetze der Notwendigkeit zu erkennen, da glauben wir, frei zu sein.
    • Ludwig Börne
  • It is not necessary for the public to know whether I am joking or whether I am serious, just as it is not necessary for me to know it myself.
  • Necessity is the last and strongest weapon.
    • Necessitas ultimum et maximum telum est.
    • Livy
  • Not even the gods fight against necessity.
  • Necessity knows no laws.
    • English proverb

External links

Wikipedia has an article about:
Look up necessity in Wiktionary, the free dictionary

1911 encyclopedia

Up to date as of January 14, 2010

From LoveToKnow 1911

NECESSITY (Lat. necessitas), a term used technically in philosophy for the quality of inevitable happening; for example, hot air necessarily tends to rise. Thus it corresponds in the sphere of action to certainty in the sphere of knowledge. That the sun will rise to-morrow is a necessary event; and men anticipate the rising with certainty. In ordinary language the conception of necessity is rendered meaningless by being referred to the present or even to the past. A current definition of necessity is "the state which cannot be otherwise than it is." Such a definition tells us nothing. How can any state be otherwise than it is? Necessity can have meaning only in reference to the future: it means absence of spontaneous power in that which acts necessarily. For the origin of the conception we must look to our inward personal experience of constraint. When we are acting under physical or mathematical or logical or moral necessity we are so far precluded from spontaneous action - in common phrase, we can do no otherwise - though the causes of constraint may be of very different kinds. In ethics the term necessitarianism is applied to that view of human action which regards all action as dictated by external causes (cf. Determinism). The sense in which, if at all, the human mind can cognize necessity, i.e. causal connexion between events or states, has been the subject of vigorous discussion among philosophers. By sceptics and empiricists it is held that a law is merely a crystallized summary of observed phenomena. Thus J. S. Mill denies that a general proposition is more than an enumeration of particulars, and hence that syllogistic reasoning cannot amplify knowledge (see Syllogism). It is clear that the senses cannot apprehend causal connexion, and this impossibility gives rise to a prior conception according to which the conception of necessity is purely intellectual (see Metaphysics).

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