According to the accepted teaching of theologians, it is lawful, in the defense of life or limb, of property of some importance, and of chastity, to repel violence with violence, even to the extent of killing an unjust assailant. This is admitted to be true with the reservation included in the phrase "servato moderamine inculpatae rutelae." That is, only that degree of violence may be employed which is necessary adequately to protect one from the attack. For example, if it were enough in the circumstances to maim an enemy it would be unlawful to kill him. It is likewise lawful to aid another to the same extent and within the same limits as are permissible for self-defense. (See HOMICIDE.)
GURY, Comp. Theol. Moral. (Prato, 1901) I, 381; LIGUORI, n. 380.
APA citation. (1907). Unjust Aggressor. In The Catholic Encyclopedia. New York: Robert Appleton Company. http://www.newadvent.org/cathen/01210a.htm
MLA citation. "Unjust Aggressor." The Catholic Encyclopedia. Vol. 1. New York: Robert Appleton Company, 1907. <http://www.newadvent.org/cathen/01210a.htm>.
Ecclesiastical approbation. Nihil Obstat. March 1, 1907. Remy Lafort, S.T.D., Censor. Imprimatur. +John Cardinal Farley, Archbishop of New York.
Contact information. The editor of New Advent is Kevin Knight. My email address is feedback732 at newadvent.org. (To help fight spam, this address might change occasionally.) Regrettably, I can't reply to every letter, but I greatly appreciate your feedback — especially notifications about typographical errors and inappropriate ads.