Z, under the influence of madness attempts to kill A, Z is guilty of no offence. But A has the same right of private defence which he would have if Z were sane.
The right of private defence may be exercised against acts done in a state of unsoundness of mind, intoxication, immature understanding or under a mistake of fact. In short, it is available both against acts—whether punishable or not—effect the safety of person or property.
This is the law contained in Section 98. The right of private defence can, however, be exercised only within certain limits which are prescribed in Section 99. Under Section 99, there is no right of private defence against the following acts: —
(i) An act which does not reasonably cause the apprehension of death or grievous hurt if done or attempted to be done (a) by a public servant, or (b) under the direction of a public servant acting in good faith under the colour of his office, though that act may not be strictly justifiable by law;
(ii) In cases in which there is time to have recourse to public authorities.
A person is not deprived of the right of private defence against acts of or acts done by the direction of a public servant unless he knows or has reason to believe that the person doing the act is a public servant or the person doing the act by the direction of a public servant is acting by such direction and if such person has authority in writing unless he produces such authority.
The right of private defence in no case extends to the inflicting of more harm than is necessary.
The right of private defence may extend even to the voluntarily causing of death in the following cases only:
(1) Assault causing reasonable apprehension of death, grievous hurt, rape or other immoral offences; (2) kidnapping or abducting; (3) wrongful confinement under circumstances causing reasonable apprehension that the defender will be unable to have recourse to public authorities for his release (Section 100); (4) robbery; (5) house-breaking by night; (6) mischief by fire to building, tent or vessel used as a human dwelling or for the custody of property; (7) theft, mischief, or house-trespass reasonably causing the apprehension of death or grievous hurt (Section 103).
The right of private defence extends to any harm, short of death in other cases (Sections 101, 102). Every man’s house is his castle and he has a right to defend both his person and property. He who preserves his own life at the expense of another man’s is excusable through unavoidable necessity.
If in an assault causing apprehension of death the defender is so situated that he cannot exercise the right of private defence without risk of harm to an innocent person he may even run that risk (Section 106). A is attacked by a mob who attempts to murder him.
He cannot effectively exercise the right of private defence without firing on the mob and he cannot fire without risk of harming young children who are mingled with the mob. A commits no offence if by so firing he harms any of the children.