Whether It Is Lawful to Kill a Man in Self-defense?
Objection 1: It would seem that nobody may lawfully kill a man in
self-defense. For Augustine says to Publicola (Ep. xlvii): "I do not
agree with the opinion that one may kill a man lest one be killed by
him; unless one be a soldier, exercise a public office, so that one
does it not for oneself but for others, having the power to do so,
provided it be in keeping with one's person." Now he who kills a man
in self-defense, kills him lest he be killed by him. Therefore this
would seem to be unlawful.
Obj. 2: Further, he says (De Lib. Arb. i, 5): "How are they free from
sin in sight of Divine providence, who are guilty of taking a man's
life for the sake of these contemptible things?" Now among
contemptible things he reckons "those which men may forfeit
unwillingly," as appears from the context (De Lib. Arb. i, 5): and
the chief of these is the life of the body. Therefore it is unlawful
for any man to take another's life for the sake of the life of his
own body.
Obj. 3: Further, Pope Nicolas [*Nicolas I, Dist. 1, can. De his
clericis] says in the Decretals: "Concerning the clerics about whom
you have consulted Us, those, namely, who have killed a pagan in
self-defense, as to whether, after making amends by repenting, they
may return to their former state, or rise to a higher degree; know
that in no case is it lawful for them to kill any man under any
circumstances whatever." Now clerics and laymen are alike bound to
observe the moral precepts. Therefore neither is it lawful for laymen
to kill anyone in self-defense.
Obj. 4: Further, murder is a more grievous sin than fornication or
adultery. Now nobody may lawfully commit simple fornication or
adultery or any other mortal sin in order to save his own life; since
the spiritual life is to be preferred to the life of the body.
Therefore no man may lawfully take another's life in self-defense in
order to save his own life.
Obj. 5: Further, if the tree be evil, so is the fruit, according to
Matt. 7:17. Now self-defense itself seems to be unlawful, according
to Rom. 12:19: "Not defending [Douay: 'revenging'] yourselves, my
dearly beloved." Therefore its result, which is the slaying of a man,
is also unlawful.
_On the contrary,_ It is written (Ex. 22:2): "If a thief be found
breaking into a house or undermining it, and be wounded so as to die;
he that slew him shall not be guilty of blood." Now it is much more
lawful to defend one's life than one's house. Therefore neither is a
man guilty of murder if he kill another in defense of his own life.
_I answer that,_ Nothing hinders one act from having two effects,
only one of which is intended, while the other is beside the
intention. Now moral acts take their species according to what is
intended, and not according to what is beside the intention, since
this is accidental as explained above (Q. 43, A. 3; I-II, Q. 12, A.
1). Accordingly the act of self-defense may have two effects, one is
the saving of one's life, the other is the slaying of the aggressor.
Therefore this act, since one's intention is to save one's own life,
is not unlawful, seeing that it is natural to everything to keep
itself in _being,_ as far as possible. And yet, though proceeding
from a good intention, an act may be rendered unlawful, if it be out
of proportion to the end. Wherefore if a man, in self-defense, uses
more than necessary violence, it will be unlawful: whereas if he
repel force with moderation his defense will be lawful, because
according to the jurists [*Cap. Significasti, De Homicid. volunt. vel
casual.], "it is lawful to repel force by force, provided one does
not exceed the limits of a blameless defense." Nor is it necessary
for salvation that a man omit the act of moderate self-defense in
order to avoid killing the other man, since one is bound to take more
care of one's own life than of another's. But as it is unlawful to
take a man's life, except for the public authority acting for the
common good, as stated above (A. 3), it is not lawful for a man to
intend killing a man in self-defense, except for such as have public
authority, who while intending to kill a man in self-defense, refer
this to the public good, as in the case of a soldier fighting against
the foe, and in the minister of the judge struggling with robbers,
although even these sin if they be moved by private animosity.
Reply Obj. 1: The words quoted from Augustine refer to the case when
one man intends to kill another to save himself from death. The
passage quoted in the Second Objection is to be understood in the
same sense. Hence he says pointedly, "for the sake of these things,"
whereby he indicates the intention. This suffices for the Reply to
the Second Objection.
Reply Obj. 3: Irregularity results from the act though sinless of
taking a man's life, as appears in the case of a judge who justly
condemns a man to death. For this reason a cleric, though he kill a
man in self-defense, is irregular, albeit he intends not to kill him,
but to defend himself.
Reply Obj. 4: The act of fornication or adultery is not necessarily
directed to the preservation of one's own life, as is the act whence
sometimes results the taking of a man's life.
Reply Obj. 5: The defense forbidden in this passage is that which
comes from revengeful spite. Hence a gloss says: "Not defending
yourselves--that is, not striking your enemy back."
_______________________