1. Anyone who acts in defense of his person or rights, provided that the following circumstances concur;
First. Unlawful aggression.
Second. Reasonable necessity of the means employed to prevent or repel it.
Third. Lack of sufficient provocation on the part of the person defending himself.
2. Anyone who acts in defense of the person or rights of his spouse, ascendants, descendants, or legitimate, natural or adopted brothers or sisters, or his relatives by affinity in the same degrees and those consanguinity within the fourth civil degree, provided that the first and second requisites prescribed in the next preceding circumstance are present, and the further requisite, in case the revocation was given by the person attacked, that the one making defense had no part therein.
3. Anyone who acts in defense of the person or rights of a stranger, provided that the first and second requisites mentioned in the first circumstance of this Art. are present and that the person defending be not induced by revenge, resentment, or other evil motive.
4. Any person who, in order to avoid an evil or injury, does not act which causes damage to another, provided that the following requisites are present; First. That the evil sought to be avoided actually exists; Second. That the injury feared be greater than that done to avoid it; Third. That there be no other practical and less harmful means of preventing it.