| 释义 |
necessity
n. A general defence to a criminal offence, usually understood as a justification rather than an excuse, on the grounds that pressure of circumstances compelled the defendant to commit an illegal act. Necessity involves a situation in which the defendant commits an offence as a result of being faced with the choice of two evils; unlike duress, the alternative evil is not a threat from another person but some other circumstance, as when the need to reach a fire leads the driver of a fire-engine to go through a red traffic light. The extent to which English law accepts a defence of necessity to a criminal charge (as opposed to one of duress or self-defence) is unclear. Although this was not in a criminal case, the House of Lords recently ruled that a surgeon may have a defence of necessity if he operates in order to save life (Re A (Children) (conjoined twins; surgical separation) [2001] Fam 147). Necessity is not, however, a defence to charges of theft or murder (e.g. when shipwreck victims kill and eat one of their number: R v Dudley and Stephens (1884) 14 QBD 273) and it is not usually a defence to driving offences. The definitions of some statutory offences incorporate such expressions as “unlawfully” or “without lawful authority or excuse” and so should admit necessity defences. Other statutory provisions (1) authorize police and fire officers, if necessary, to break into premises when a fire has broken out and do everything necessary to extinguish it; and (2) provide qualified exemption from compliance with traffic lights for fire engines, ambulances, and police vehicles. Necessity is in some circumstances a defence to an action in tort, but it is generally limited to action taken to protect life or property in an emergency not caused by the defendant’s negligence. The steps taken in the emergency must be reasonable. An exception is in the case of a permanently incapacitated individual, where necessity covers all activities that are in the person’s best interests. |