Home  »  The Rights of War and Peace  »  Chapter IV: On the Right of Killing an Enemy in Lawful War, and Committing Other Acts of Hostility

Hugo Grotius (1583–1645). The Rights of War and Peace. 1901.

Book III

Chapter IV: On the Right of Killing an Enemy in Lawful War, and Committing Other Acts of Hostility

  • General explanation of the effects of formal war—Distinction between lawful and innocent impunity—Merit of the latter—Examples added to explain it—General effects of former war considered with respect to lawful impunity—The reason of their introduction—Historical testimonies—By the right all persons, found within an enemy’s territory, objects of hostility—Also all going thither before the war—The subjects of an enemy liable to be seized everywhere, except protected by the laws of a neutral territory—Case of women and children—Case of prisoners—Of those whose voluntary offer of surrender is rejected—Unconditional surrender—Retaliation—Obstinate defence—Hostages.

  • I. SERVIUS in his comment on the passage of Virgil, where that poet says that war “will authorise mutual acts of destruction and rapine,” in tracing the fecial or herald’s law to Ancus Martius, and even beyond him to a still more remote period, remarks that, “if ever the persons or property of subjects, belonging to the Roman state, were seized and carried off by any other nation, the principal Herald, or King at arms went out with the sacred ministers, who presided at the making of solemn treaties, and proceedings to the verge of the territories of the offending nation, declared with a loud voice the cause of the war, and the refusal of that nation either to restore what had been seized, or to deliver up the aggressors to justice. After this he threw a spear to indicate that war and all its consequences were from that moment begun.”

    The commentator had previously observed that the ancients gave the name of rapine to every act of hostility even where there was no act of plunder committed; and they likewise called every kind of restitution a satisfaction.

    By this explanation we learn that whenever war is proclaimed between two states or sovereigns, it is accompanied with certain rights or consequences, which do not NECESSARILY belong to war itself. And this is perfectly conformable to the examples from the Roman Lawyers, which have been before produced.

    II. But it will be proper to consider how far the lawfulness, which Virgil speaks of, extends. For the term lawful sometimes implies whatever is just and pious in all respects, although the pursuit of a different course may perhaps be more laudable: according to the expression of St. Paul, who says, “all things are lawful to me, but all things are not expedient.” Ulpian is speaking of a seller, who, at the expiration of a certain period, is not answerable for the safety of goods, which a buyer has neglected to take away, says he, will yet think himself bound in EQUITY to preserve them with all imaginable care. On some occasions when it is said, that men may LAWFULLY do a thing, the expression only means that doing such act will not subject them to human and legal penalties, but it by no means indicates that the action is strictly conformable to the rule of religion and morality. Thus among the Lacedaemonians and Egyptians stealing was allowed: an indulgence that by no means took away the GUILT of theft.

    Cicero in the fifth of his Tusculan questions, speaking of Cinna, beautifully and justly points out this abuse of the word, LAWFUL. “He seems to me, says he, a wretched man indeed for having done those acts, and for having been in a situation, where they might be thought lawful. It can never be lawful for any man to do wrong: but we fall into a great mistake in the use of that word: for we consider a thing to be lawful, which any one may do with impunity.” This is the meaning, in which the term is generally understood, as the same orator, in addressing the judges in behalf of Rabirius Posthumus, observes, “it behoves you to consider, what is becoming your character, and not what the rigour of the law allows you to inflict. For if you consult the full extent of your authority, you may make away with any citizen you please.”

    In the same manner legislators, as it was proved in a former book of this treatise, are not accountable, in their legislative capacity, to any human tribunal, for the laws, which they make, yet they cannot, in a moral point of view, avail themselves of this transcendent power to enact a thing that is evidently unjust. In this sense we often meet with a distinction made between what is proper or right, and what is lawful. Thus Cicero, in his speech for Milo, makes the LAW OF NATURE the standard of what is RIGHT, and LEGAL AUTHORITY, the standard of what is lawful.

    III. Thus qualified, the annoyance of an enemy, either in his person or property, is lawful. This right extends not only to the power engaged in a just war, and who in her hostilities confines herself within the practice established by the law of nature, but each side without distinction has a right to employ the same means of annoyance. So that any one taken in arms, even in another’s territory, cannot be treated as a robber, malefactor, or murderer, nor can even that neutral power, in whose territory he is taken, treat him as an enemy, for being found in arms.

    IV. This principle was established by nations to prevent others from interfering in their disputes, or giving the law to them respecting the rights of war. Besides, if this were not the case, neutral powers would frequently be involved in the wars of others. A reason which the people of Marseilles urged in the dispute between Caesar and Pompey. They alleged that they had neither sufficient judgment to determine on which side justice lay, nor, if they could determine, had they strength to give effect to their decisions.

    A spectator indeed is but ill qualified to judge, how far, even in the most just war, self-defence, the attainment of indemnity, or the punishment of an aggressor, may be carried. These are points, which, on many, if not most, occasions must be left to the conscience and discretion of the belligerents themselves: a mode far preferable to that of appealing to the mediation, and decision of disinterested and neutral powers. Livy has given an address of the Achaeans to the senate, in which they ask, “how their availing themselves of the rights of war can ever be fairly called in question, or made a subject of discussion?”

    Besides the impunity attending certain actions done in war, the acquisition of territory by the right of conquest is another topic of consideration, which will hereafter be examined.

    V. The lawfulness of injuring or destroying the person of a public enemy is supported by the testimony of many of the best writers, both poets, moralists, and historians. In one of the tragedies of Euripides, there is a proverb, which says, that “to kill a public enemy, or an enemy in war is no murder.” Therefore the custom of the ancient Greeks, which rendered it unlawful and impious to use the same bath, or to partake of the same festivities and sacred rites with a person who had killed another in time of peace, did not extend to any one who had killed a public enemy in war. Killing an enemy is indeed everywhere called a right of war. “The rights of war, says Marcellus in Livy, support me in all that I have done against the enemy.” And the same historian gives the address of Alcon to the Saguntines, where he says, “You ought to bear these hardships, rather than suffer your own bodies to be mangled, and your wives and children to be seized and dragged away before your eyes.” Cicero in his speech in defence of Marcellus passes a high encomium upon the clemency of Caesar, who, “by the laws of war and the rights of victory, might have put to death all, whom he had spared and protected.” And Caesar observes to the Eduans, that “it was an act of kindness in HIM, to spare those whom the laws of war would have authorised him to put to death.”

    But the rights of war, for which these writers plead, could not PERFECTLY JUSTIFY the putting prisoners to death, but could only grant IMPUNITY to those who availed themselves of the barbarous custom. There is a wide difference however between actions like these, and destroying an enemy by proper means of hostility. For, as Tacitus says, “in the leisure hours of peace the merits and demerits of every case may be examined and weighed, but, in the tumult and confusion of war, the innocent must fall with the guilty”: and the same writer, in another place, observes, that “there are many actions, which the principles of humanity cannot ENTIRELY approve, but which the policy of war requires.” And it is in this, and no other sense that Lucan has said, “the complexion of right may be assigned to what is wrong.”

    VI. This right of making lawful what is done in war is of great extent. For in the first place it comprises, in the number of enemies, not only those who actually bear arms, or who are immediately subjects of the belligerent power, but even all who are within the hostile territories, as appears from the form given by Livy, who says, that “war is declared against the sovereign, and all within his jurisdiction.” For which a very good reason may be assigned; because danger is to be apprehended even from THEM, which, in a continued and regular war, established the right now under discussion.

    Reprisals do not come exactly under the same rule. For like taxes, they were introduced for the discharge of public debts, for no part of which temporary residents, or foreigners are answerable. Therefore Baldus is right in his observation, that, after war is actually begun, much greater latitude is allowed, than in the bare right of making reprisals. So that what is said of foreigners, who enter into an enemy’s country, and reside there, after war is avowedly declared and begun, is undoubtedly true.

    VII. But persons, who had gone to reside there before the war was begun, seem by the law of nations to be included in the number of enemies, unless within a reasonable time they chuse to withdraw. So that the Corcyraeans, when going to besiege Epidamnus, gave leave to all strangers to withdraw, denouncing that they would otherwise be treated as enemies.

    VIII. But the persons of natural-born subjects, who owe permanent allegiance to a hostile power may, according to the law of nations, be attacked, or seized, wherever they are found. For whenever, as it was said before, war is declared against any power, it is at the same time declared against all the subjects of that power. And the law of nations authorises us to attack an enemy in every place: An opinion supported by most legal authorities: thus Marcian says “that deserters may be killed in the same manner as enemies, wherever they are found.” They may be lawfully killed there, or in their own country, in the enemy’s country, in a country belonging to no one, or on the sea. But as to the unlawfulness of killing, or violently molesting them in a neutral territory, this protection does not result from any personal privileges of THEIR OWN, but from the rights of the SOVEREIGN of that country. For all civil societies had an undoubted right to establish it as a standing maxim that no violence should be offered to any person within their territories, nor any punishment inflicted but by due process of law. For where tribunals retain their authority in full vigour, to try the merits of every offence, and, after impartial inquiry, to acquit the innocent, or condemn the guilty, the power of the sword must be restrained from inflicting promiscuous death.

    Livy mentions the circumstance of seven Carthaginian gallies riding at anchor in a port belonging to Syphax, who was then at peace with the Carthaginians and Romans, Scipio arrived at that time, with two gallies, which might have been attacked and sunk by the Carthaginians, before they could enter the port: a brisk wind rising carried them in, before the Carthaginians could weight anchor; but out of respect to the king’s authority they durst not attack the Romans in his harbour.

    IX. But to return to the subject, which is, to decide how far the power of lawfully destroying an enemy, and all that belong to him, extends. An extent of which we may form some conception from the very circumstance, that even women and children are frequently subject to the calamities and disasters of war. There is no occasion to allege in this place, as an example, the conduct of the Hebrews, who slew the women and children of the Heshbonites, and who were commanded to execute vengeance upon the Canaanites, and upon all, who were involved in the same guilt. Those examples, where God MANIFESTLY interposes his commands, are not to be drawn into a precedent for authorising actions of the SAME kind on DIFFERENT occasions. For the supreme and disposing power of God can never properly be compared with that, which men are allowed to exercise over each other. The Psalmist’s expression of the Babylonian children being dashed against the stones is a much stronger proof of the custom commonly prevailing among nations, in the use of victory, to which the language of Homer bears a close resemblance, where the poet says, that “in the cruel rage of war, even the bodies of infant-children were dashed against the ground.” Thucydides relates, that when Mycalessus was captured by the Thracians, they put all, even women and children to the sword. Arrian relates the same of the Macedonians, when they took the city of Thebes. And Germanicus Caesar, according to the account of Tacitus, laid waste whole cantons of the Marsians, a people of Germany, with fire and sword, to which the historian adds, “without sparing either age or sex.” The Jewish women and children too were exposed by Titus, to be torn to pieces by wild beasts at a public spectacle. Yet neither of those generals were thought deficient in humanity, so much had custom reconciled the minds of men to this barbarous usage. So that the massacre of the aged, like that of Priam by Pyrrhus, is no way surprising.

    X. The right of putting prisoners of war to death, was so generally received a maxim, that the Roman Satirist has founded an adage upon it, and said, “that when you can sell a prisoner for a slave, it would be absurd to kill him.” Words which imply the full power of doing so, if the captor thought proper. The commentators indeed assign the act of saving, as the derivation of the Latin word, servus, a slave. Thus Thucydides speaks of the prisoners taken at Epidamnus, and killed by the Corcyraeans, and Hannibal is reported to have massacred five thousand prisoners at once. Nor was this power limited by the law of nations to any particular time, though it was controuled by greater restrictions in some places, than in others.

    XI. Besides many examples occur of suppliants, being killed. Both ancient poets and historians relate such actions, as ordinary practices, authorised by the laws of war. Augustin commends the Goths for sparing suppliants, who had fled to churches for refuge, and adds by way of comment, that “they deemed it unlawful to avail themselves of the power, which had usually been allowed by the laws of war.”

    Nor did those who offered to surrender always experience the lenity and mercy, which they sought thereby. Tacitus relates, that when the city of Uspes was invested, the besieged sent a deputation with offers of an immediate surrender, and of no less than ten thousand slaves, on condition that the free-born should remain unhurt. The terms were rejected—A proof that such a rejection was thought conformable to the rights of war.

    XII. But even after an unconditional surrender, we find that those, who had capitulated were sometimes put to the sword. In this manner the princes of Pometia were treated by the Romans, the Samnites by Sylla, the Numidians and Vercingetorix by Caesar. It was almost a standing practice with the Romans to crown their triumphs with the death of an enemy’s generals, whether made prisoners actually in the field, or by capitulation. Cicero notices this custom in his fifth speech against Verres. Livy may be consulted on this point in many parts of his history, particularly in the twenty-eighth book: and Tacitus also in the 12th book of his Annals. The latter writer, in the first book of his HISTORY, relates that Galba ordered every tenth man of those, whom he had, upon their earnest supplication, admitted to surrender, to be beheaded: and Caecina, after the capitulation of Aventicum, punished Julius Alpinus, one of the leading men, with death, as a chief promoter of the war, leaving the rest to the mercy or cruelty of Vitellius.

    XIII. Historians sometimes account for this right of putting enemies to death, especially prisoners, or suppliants, either on the score of retaliation, or for obstinate resistance. These may sometimes be the real, but cannot be the JUSTIFIABLE motives of such proceedings. For the law of retaliation, strictly and properly so called, must be directly enforced upon the person of the delinquent himself. Whereas, in war, what is called retaliation frequently redounds to the ruin of those, who are no way implicated in the blame. The general consequences of war are thus described by Diodorus Siculus, “they could not be ignorant, says he, having learnt from experience, that all being involved in the common fortune of war, they are liable on both sides in defeat, to suffer the same calamities, which they themselves would have inflicted upon the conquered party.”

    But as the Neapolitans reply to Belisarius, in Procopius, no one can he thought deserving of punishment for a resolute adherence to the side on which he is engaged, especially when actuated by natural and just motives in his choice of that side. So far from incurring guilt by such a resolution, it is on the other hand more criminal for any one to desert his post: and so it was judged by the military laws of ancient Rome. Livy says, it was a capital offence, for which no fear of danger could be pleaded as an excuse. So that in the rigid application of this right, OWING TO ITS IMPORTANCE, every one is left to use his own discretion, and there may be times and circumstances, in which the law of nations will justify its full exertion.

    XIV. The same right was exercised upon hostages also, not only upon those who had bound themselves, as it were, by convention, but even upon those, who had been delivered up by others. Two hundred and fifty hostages were once massacred by the Thessalians, and the Volsci Aurunci to the amount of three hundred by the Romans. It is to be observed that children were sometimes given, as hostages, which we find was done by the Parthians, and by Simon, who was one of the Maccabees. And in the times of Porsena it was usual to deliver women, as hostages: a practice, which, as Tacitus informs us, was followed by the Germans.

    XV. As the law of nations permits many things, in the manner above explained, which are not permitted by the law of nature, so it prohibits some things which the law of nature allows. Thus spies, if discovered and taken, are usually treated with the utmost severity. Yet there is no doubt, but the law of nations allows any one to send spies, as Moses did to the land of promise, of whom Joshua was one.

    Persons of that description may sometimes be LAWFULLY employed by those, who are engaged in an EVIDENTLY just war. Others too, who have not such evident proofs of the justice of their cause, may plead the rights of war as a vindication for employing such persons.

    But if any are to be found, who disdain to avail themselves of such a privilege, or opportunity, no argument either FOR, or AGAINST the LAWFULNESS of employing spies can be drawn from their conduct, which proceeds rather from a nobleness of mind, and a confidence in open strength, than from any decided opinion upon the subject.