LEGAL PRINCIPLE: CRIMINAL LAW – Self-Defence – Conditions for Availability
PRINCIPLE STATEMENT
When a person is unlawfully assaulted and has not provoked the assault, it is lawful for them to use such force to the assailant as is reasonably necessary to make effectual defense against the assault; the force which may be used must not be intended, and should not be such as is likely, to cause death or grievous harm.
RATIO DECIDENDI (SOURCE)
"When a person is unlawfully assaulted, and has not provoked the assault, it is lawful for him to use such force to the assailant as is reasonably necessary to make effectual defence against the assault. The force which may be used, in such circumstances, must not be intended, and should not be such as is likely, to cause death or grievous harm."
EXPLANATION / SCOPE
Self-defense as a complete defense to assault/homicide charges requires: (1) Unlawful assault: The accused was attacked without legal justification; (2) No provocation: The accused didn’t provoke the assault (provoked person cannot claim pure self-defense); (3) Reasonably necessary force: The force used was what a reasonable person would consider necessary for effective defense; (4) Force limitation: The force must not be intended to cause, nor likely to cause, death or grievous harm. Element (4) limits self-defense scope—deadly force cannot be justified under basic self-defense (though it may be under extreme necessity/imminent death situations governed by other provisions). “Reasonably necessary” is assessed objectively: would a reasonable person in the accused’s position use such force? Factors include: nature of attack, disparity in size/strength, availability of retreat, and immediacy of danger. If the accused uses excessive force (particularly deadly force), self-defense fails though provocation might reduce murder to manslaughter. This principle balances protecting victims of assault against preventing disproportionate retaliation.