Self-Defense in Criminal Law: Justification Principles

Causes of Justification: Self-Defense Principles

Self-Defense: A Justification Principle

Self-defense shares with a state of necessity the factual existence of a conflict between two legal rights, where the legal system may sacrifice one to preserve the other. However, self-defense is distinguished by the fact that the conflict arises between the legal right of the attacker and that of the attacked. This gives it a greater scope of action compared to a state of necessity, where the subject acts to prevent harm for which "nobody is at fault."

Basis for Exemption from Punishment in Self-Defense

Self-defense is credited with a dual basis or function: self-governance and the protection of the law. Those who act in self-defense do not perform acts contrary to law, even if they damage one right to save another. In any case, to the extent that, by definition, a defensive act operates outside ordinary legal channels, exemption from punishment is granted only in rare instances, as reflected in the restrictive legal requirements for its appreciation.

Concept of Self-Defense

Self-defense is a justification that allows exemption from criminal responsibility for those who perform the typical behavior necessary to prevent an unlawful attack on their own or another's legal rights.

Objective Criteria: Unlawful Aggression

Unlawful aggression is the main differentiator between self-defense and a state of necessity. Unlike self-defense, a state of necessity applies to cases where danger emanates from lawful conduct or objective hazard sources (e.g., natural disasters). This distinction has important consequences for defining justified acts in each case. Thus, while one who is the subject of unlawful aggression is entitled to do whatever is reasonably necessary to defend themselves – as it is the offender who places themselves outside the law and must bear the consequences of their actions – one who acts to prevent harm for which no one is "to blame" can only claim a justification (of necessity) where the harm caused is not greater than the harm avoided.