necessity. 1.Criminal law. A justification defense for a person who acts in an emergency that he or she did not create and who commits a harm that is less severe than the harm that would have occurred but for the person’s actions. • For example, a mountain climber lost in a blizzard can assert necessity as a defense to theft of food and blankets from another’s cabin. — Also termed choice of evils; duress of circumstances; lesser-evils defense. See lesser-evils defense under DEFENSE(1). [Cases: Criminal Law 38. C.J.S. Criminal Law §§ 49–53.] 2.Torts. A privilege that may relieve a person from liability for trespass or conversion if that person, having no alternative, harms another’s property in an effort to protect life or health.

“In some cases even damage intentionally done may not involve the defendant in liability when he is acting under necessity to prevent a greater evil. The precise limits of the defence are not clear, for it has affinities with certain other defences, such as act of God, self-help, duress, or inevitable accident. It is distinguishable from self-defence on the ground that this presupposes that the plaintiff is prima facie a wrongdoer: the defence of necessity contemplates the infliction of harm on an innocent plaintiff. The defence, if it exists, enables a defendant to escape liability for the intentional interference with the security of another’s person or property on the ground that the acts complained of were necessary to prevent greater damage to the commonwealth or to another or to the defendant himself, or to their or his property. The use of the term necessity serves to conceal the fact that the defendant always has a choice between two evils. This is what distinguishes the defence of necessity from that of impossibility.” R.F.V. Heuston, Salmond on the Law of Torts 493 (17th ed. 1977).

manifest necessity.A sudden and overwhelming emergency, beyond the court’s and parties’ control, that makes conducting a trial or reaching a fair result impossible and that therefore authorizes the granting of a mistrial. • The standard of manifest necessity must be met to preclude a defendant from successfully raising a plea of former jeopardy after a mistrial. [Cases: Double

Jeopardy 99. C.J.S. Criminal Law § 230.] military necessity.See MILITARY NECESSITY.

moral necessity.A necessity arising from a duty incumbent on a person to act in a particular



physical necessity.A necessity involving an actual, tangible force that compels a person to act

in a particular way.

private necessity.Torts. A necessity that involves only the defendant’s personal interest and thus provides only a limited privilege. • For example, if the defendant harms the plaintiff’s dock by keeping a boat moored to the dock during a hurricane, the defendant can assert private necessity but must compensate the plaintiff for the dock’s damage. [Cases: Negligence 510(3). C.J.S.

Negligence §§ 240, 317.]

public necessity.Torts. A necessity that involves the public interest and thus completely excuses the defendant’s liability. • For example, if the defendant destroys the plaintiff’s house to stop the spread of a fire that threatens the town, the defendant can assert public necessity.


[Blacks Law 8th]