Such a killing is permissible under the law and cannot be equated with murder, a Bench of Justices Dalveer Bhandari and Asok Kumar Ganguly said.
"The law does not require a law-abiding citizen to behave like a coward when confronted with an imminent unlawful aggression. As repeatedly observed by this court there is nothing more degrading to the human spirit than to run away in face of danger.
"The right of private defence is thus designed to serve a social purpose and deserves to be fostered within the prescribed limits," the Bench said a judgement.
The apex court passed the judgement while acquitting a convict, Darshan Singh, of the murder of his uncle Gurcharan Singh on July 15, 1991 in Punjab's Ludhiana district over a land dispute.
Darshan Singh shot dead Gurcharan Singh after the latter attacked the accused's father Bakthawar Singh with a lethal weapon on the head and then proceeded to attack him. In the scuffle that ensued Darshan Singh shot dead Gurcharan Singh.
The sessions court had acquitted him on the ground that Darshan Singh had exercised his right of self defence provided under Sections 96-106 of the IPC.
However, on an appeal from the state, the acquittal was reversed and the High Court sentenced the accused to life imprisonment following which he appealed in the apex court.Interpreting Section 96-106 of the IPC which justifies the killing of an assailant, the apex court said, the provision can be invoked where a person has a genuine apprehension that his adversary is going to attack him and reasonably believes that the attack will result in a grievous hurt.
"In that event, he can go to the extent of causing the latter's death in the exercise of the right of private defence even though the latter may not have inflicted any blow or injury on him.
"The question whether the apprehension was reasonable or not is a question of fact depending upon the facts and circumstances of each case and no straitjacket formula can be prescribed in this regard.
"The weapon used, the manner and nature of assault and other surrounding circumstances should be taken into account while evaluating whether the apprehension was justified or not," the Bench held.
According to the apex court, while enacting sections 96 to 106 of the Indian Penal Code, "the Legislature clearly intended to arouse and encourage the manly spirit of self defence amongst the citizens, when faced with grave danger".
The apex court said the right to protect one's own person and property against the unlawful aggressions of others is a right inherent in man.
"The duty of protecting the person and property of others is a duty which man owes to society of which he is a member and the preservation of which is both his interest and duty. It is, indeed, a duty which flows from human sympathy, the Bench observed.
However, the Bench cautioned that such protection must not be extended beyond the necessities of the case, otherwise it will encourage a spirit or lawlessness and disorder. The right, therefore, has been restricted to offences against the human body and those relating to aggression on property, it said.
"A mere reasonable apprehension is enough to put the right of self defence into operation, but it is also settled position of law that a right of self defence is only right to defend oneself and not to retaliate. It is not a right to take revenge.
"The citizens, as a general rule, are neither expected to run away for safety when faced with grave and imminent danger to their person or property as a result of unlawful aggression," the Bench said, while directing Darshan Singh's acquitt