LEGITIMATE DEFENSE. — One who, compelled by necessity, defends his own or another’s right concerning personal safety or a valuable possession in his own custody against an actual unjust aggression by wounding or killing the aggressor is said to act in legitimate defense, provided that the defense is proportionate to the offense.
The lawfulness of legitimate defense arises from the natural law itself and is admitted by all positive laws.
I. HISTORICAL NOTES
Already Cicero, speaking of this right, refers it to natural law: “A natura cuique tributum, ut se et corpus suum tueatur declinetque ea, quae ei nocitura sunt” (De Officiis, 1, 1). And Gaius: “naturalis ratio permittit se defendere” (D. 9, 2, 45).In Roman law, however, it was lawful to defend oneself by killing the aggressor only when life, personal integrity, or chastity were at stake; not when it concerned property, unless the personal safety of the victim was endangered by the time and place of the aggression (D. 48, 8, 9), or the thief attacked while beating the victim (D. 43, 16, 36, 9). Nevertheless, it was not lawful to anticipate the aggressor (Cod. 3, 27, 1), nor to defend oneself or one’s relatives in a bloody manner (D. 48, 8, 11).
Little is known with precision about barbarian law in this matter, owing to the diversity of sources and the opinions of interpreters; but it seems that legitimate defense was not regarded as a distinct institution, both because of the objective nature of ancient Germanic law and because of the faculty granted to private individuals to avenge homicide.
Ancient canon law confirmed the lawfulness of bloody defense (c. 7, D. 1; c. 3, X, 5, 39). Innocent III circumscribed the limits of defense “cum moderamine inculpatae tutelae” (c. 18, X, 5, 12; cf. also c. 6, V, 11 in Sext.; cap. unico in Clement., V, 4). Within the scope of the lawfulness of killing in legitimate defense, the defense of property was also included by reference to Ex. 22, 2 (3, X, 5, 12).
Canonist doctrine, long debated by jurists, was further developed by moral theologians under the guidance of ecclesiastical authority, which corrected the too lenient or rigorist opinions of both sides. Thus were condemned the opinions of those who sought to extend the field of lawful legitimate defense to the protection of honor (Denz.-U., 1177, 1180) or of material goods of very slight value or not actually in one’s possession (ibid., 1182 sqq.), or who declared lawful the suppression of a judge who was about to render an unjust sentence, or of a false accuser or false witness (ibid., 1118), of an adulterer or wife caught in flagrante delicto (ibid., 1119), or who granted the exculpating circumstance of legitimate defense even to one who could have otherwise effectively avoided the aggression, for example by flight (ibid., 1180). All these cases fail to meet the condition of necessity; in them the suppression of the adversary is not always the most suitable means of self-protection, or the sense of proportion between values is lacking.
On the other hand, opinions were considered tainted with rigorism which never recognized the lawfulness of killing the aggressor, on the ground that in legitimate defense there is always a disproportion of values in preferring one’s temporal life to the salvation of the aggressor’s soul. Opinions which found echo even among jurists and philosophers who lived more or less on the margins of Christian thought (Grotius, Kant).
In present-day canon law it is established that legitimate defense against an unjust aggressor “si debitum servetur moderamen” excludes the crime and therefore punishability; whereas, if the due moderamen is not observed, it mitigates imputability (can. 2205 § 4).
II. FOUNDATION OF LAWFULNESS
While there is agreement on the lawfulness of legitimate defense within certain well-defined limits, it is more difficult to find the ultimate reason for its lawfulness, given the clash of values and rights—our own and those of others—and the universality of the precept “Thou shalt not kill,” which seems to admit of no exceptions except by special mandate of God.St. Thomas Aquinas (Sum. Theol., 2a-2ae, q. 64, a. 7) appears to apply in this matter the principle of double effect (v. IMPUTABILITY OF EFFECTS).
The act of one who defends himself by killing the aggressor must be considered from a twofold aspect: inasmuch as it is directed to the preservation of his own life, and inasmuch as it results in the killing of the aggressor. Self-defense is entirely lawful, since it is natural for man to preserve his existence as far as possible. The killing of the aggressor, when it is not intended but only permitted for very grave reasons, is not equally imputable to the agent. Yet this much-debated passage of St. Thomas, which has been interpreted in the most obvious sense, has given rise to a whole range of interpretations and opinions from Azpilcueta to Cardinal De Lugo, from St. Antoninus to St. Alphonsus, from Lessius to Cathrein, to Waffenart, to Van Hove—especially because the holy Doctor seems to forbid the defender from directly intending the killing of the aggressor, which to some appears unacceptable, even as an excessively subtle and impractical distinction. Hence, besides the various presentations of St. Thomas’s thought, other explanations, more or less convincing, have been elaborated.
Some, indeed, explain the lawfulness by appealing to a kind of delegation that public authority would grant to one in such circumstances. But it may be objected that the Codes speak only of the exculpating effect of legitimate defense. Others resort to the necessity of safeguarding social order and consequently of promoting the common good; although it might be replied that this at most provides a criterion for manifesting the lawfulness of the act, not its ultimate foundation. Others appeal to the conflict of rights in incompatible cases: which presupposes what it is supposed to prove, namely, the lawfulness of taking the life of the aggressor. Pufendorf finds the ultimate reason in the fact that in the duties of nature no one can demand of another what he himself does not fulfill and indeed transgresses. Whoever unjustly attacks another’s rights loses his own and places himself outside the law. Yet the mutual duties among men ultimately proceed from God and do not cease unless in some way He wills or permits II. Less convincing is the theory of the necessity of law or state authorization (Notstand und Notrecht), according to which the killing of the aggressor is lawful simply because it is necessary for one’s own preservation or permitted by the state (Carrara, Pessina, etc.).
Another solution is proposed on the following grounds. In homicide there is a twofold injury: against God, the true master of our life; and against one’s neighbor, who by the very fact of existing has a right to life. But the aggressor is aware that he provokes a reaction, and thus is responsible for the consequences and removes from the bloody reaction its formal character of injury; according to the maxim: “volenti non fit iniuria.” That this bloody self-defense is not contrary to the ethical order, which has its source in God, may in part be seen from the instinct of self-defense inherent in animals and in man, who by a spontaneous impulse tends to oppose the aggressor in any way: the voice of nature seems to be the voice of the Creator.
Moreover, coercibility—that is, the moral faculty of defending one’s right even by force under certain conditions—is a quality of right itself, even if not essential, and as such derives from God, the author of things and rights. Now the right to life is a supreme good: its coercibility must therefore extend to the utmost; otherwise it would be illusory and ineffective if it did not reach the point of bloody defense.
No further elements are found in Sacred Scripture that manifest the divine will to us. There is a passage in the Old Testament (Ex. 22:2–3) that seems to allow bloody defense against a nocturnal thief, but it is uncertain whether this refers to a positive legal provision or to natural law. On the other hand, it cannot be demonstrated from Scripture that the illegality of legitimate defense is in any way established, because the passages in Mt. 5:38–39; 26:52; Rom. 12:18–19, which might seem to present some difficulty, are commonly interpreted as forbidding only the craving for revenge.
Another source of the Church’s teaching is the ecclesiastical magisterium, which has spoken in the sense indicated above.
Therefore, legitimate defense is lawful first of all against one who is a formally unjust aggressor. It is also lawful against one who is an unjust aggressor only materially, because in practice such an examination is almost always impossible, and moreover the argument drawn from the coercibility of the right applies against any type of unjust aggressor.
III. CONDITIONS FOR THE LAWFULNESS OF LEGITIMATE DEFENSE — The faculty of resorting to physical force for the protection of a right can never be unlimited; otherwise it would be arbitrary and would disrupt rather than protect the moral and juridical order.
This also holds true in the case of legitimate defense. After what has been said, it is easy to define these limits, which moralists summarize in the formula taken from the Justinian Code: “inculpatae tutelae moderatio” (Cod. 8, 4, 1).
In simpler terms, the constitutive elements of moderatio are: unjust aggression, proportional reaction, and the necessity of defense.
1. Unjust aggression
For the exculpating moderation to apply, the agent must act to repel violence directed against himself or others, violence that is unjust either in its substance or in its manner, and violence that is in act. From the danger arises a bond of universal brotherhood, by which the reaction and protection receive the stamp of legitimacy when exercised by anyone and in favor of anyone: from the selfish and personal form of self-defense and defense of one’s own, one rises to the altruistic and impersonal form of defense of the right.Violence is unjust when it is inflicted without right; and it is sufficient that the violence be unjust in itself, without needing to refer it to the responsibility of the aggressor. Even if the aggressor were a madman or a drunkard, if his act has given rise to the necessity of a prompt reaction, the reaction is justified. Nevertheless, for it to have an exculpating effect, it is necessary that the violence, that is, the evil or danger against which one reacts, be actual, at least morally.
A mere threat, not accompanied by an act or circumstances that induce in the threatened person the fear of imminent execution, would not suffice to remove the imputability of the reaction; but on the other hand, the fear of imminent execution may suffice, in accordance with the ancient maxim of law and common sense, that “one is less bound to wait until he is struck.”
If the attack has been repelled, and without reasonable cause to fear that the aggressor will persist and return to hostility, the aggressor proceeds to further violence against him, the justification of moderation cannot be invoked for these subsequent acts. In all such cases one must rather speak of vengeance, and at most, according to the various circumstances and the sentiment that drove the subject to act, one may have the figure of an excess of defense or of provocation.
2. Proportional reaction
One cannot take away from another a maximum good for a minimum good or for one that can be defended in another way. For this requirement, legitimate defense must be restricted to attacks on life, personal integrity, freedom, and attacks on modesty that are such as to place the victim in a condition of having to defend himself. The moderation for an attack on goods must be regulated morally in proportion to the intrinsic value of the contested good, the condition of the one threatened, and the possibility of otherwise reclaiming II. For these reasons, it is not easy to translate this into figures, though some have attempted II. It certainly cannot be less than the relatively grave matter of theft (cf. Denz.-U., 1181).3. Necessity of defense
This must be examined and understood both in relation to the proportions between the reaction and the violence against which one reacts, and in relation to the possibility of avoiding it otherwise.The proportion between the violence and the reaction must not be understood in a merely material sense, but regard must also be had to the means available to the agent at the moment of aggression, to the possibility for him of coping with the imminent danger in another way, and to his state of mind.
As for the inevitability of the danger, it must be such that it cannot be avoided by prayer, shouting, or flight. The obligation, however, to flee cannot be affirmed for one who has been assigned to remain at his post or who cannot do so without seriously compromising his own dignity. In evaluating all this, one must take into account the disturbance of mind produced in the agent by the fear of violence or danger.
These constitutive elements of moderatio, besides being found in natural law, are more or less taken into account also in positive law. Even penal codes usually consider legitimate defense as a circumstance that excludes the crime (though some penal codes take it into account only for certain crimes).
The current Italian Penal Code excludes punishability when one has committed an act that would constitute a crime, having been compelled by the necessity of defending a right of one’s own or another’s against an actual danger of unjust offense, provided that the defense is proportionate to the offense (art. 52). If, however, the limits imposed by necessity are exceeded negligently, the act is punishable as a negligent crime (v. culpa), provided a penalty is prescribed.