The Law of War and Peace (1625)

by Hugo Grotius

On Doubtful Causes of War

I.     On the source of the causes of doubt in moral questions.
What Aristotle wrote is perfectly true, that certainty is not to be found in moral questions in the same degree as in mathematical science. This comes from the fact that mathematical science completely separates forms from substance, and that the forms themselves are generally such that between two of them there is no intermediate form,’ just as there is no mean between a straight and a curved line. In moral questions, on the contrary, even trifling circumstances alter the substance, and the forms, which are the subject of inquiry, are wont to have something intermediate, which is of such scope that it approaches now more closely to this, now to that extreme.

Thus it comes about that between what should be done and what it is wrong to do there is a mean, that which is permissible; and this is now closer to the former, now to the latter. Hence there often comes a moment of doubt, just as when day passes into night, or when cold water slowly becomes warm. This is what Aristotle means when he says: ‘Oftentimes it is hard to decide what choice one should make.’ Andronicus of Rhodes states the matter thus: ‘It is hard to distinguish what is truly just from that which appears to be so.’

II.     Nothing is to be done contrary to the dictates of one’s mind, however erroneous they may be.
1.   First of all we must hold to the principle that, even if something is in itself just, when it is done by one who, taking everything into consideration, considers it unjust, the act is vicious. This in fact is what the Apostle Paul meant by saying, ‘Whatsoever is not of faith, is sin,’ where ‘faith’ signifies the judgement of the mind on the matter. For God has given the power of judgement as a guide for human actions, and if this is treated with contempt the mind becomes brutish.

2.   Nevertheless, it often happens that the judgement presents no certainty, but is undecided. If this indecision cannot be dissipated by careful consideration, we must follow the precept of Cicero’ That is a good rule which they lay down who bid you not to do a thing when you are in doubt whether it is right or wrong.’ The, Jewish teachers also say: ‘Hold aloof from a doubtful matter.’

This course, however, cannot be pursued where one really must; do one of two things, and yet is in doubt whether either is right,, In that case he will be allowed to choose that which appears to him; to be less wrong. For always, when a choice cannot be avoided, the lesser evil assumes the aspect of the good. ‘We must take the least, among evils,’ says Aristotle; and Cicero, ‘Of evils one must choose: the least.’ Quintilian writes: ‘In a comparison of evils, the lesser evil takes the place of the good.’

III.     One’s judgement may be influenced in either direction by arguments from facts.
Very often in a doubtful matter, however, after some investigation the mind does not remain neutral but is influenced to this side or that by arguments drawn from the facts, or by the opinion which it gathers from other men who express their view of the matter; For here also is the saying of Hesiod true, that the most excellent thing is to be wise of one’s self; the next best, to be directed by. the help of others.

Arguments from the facts are drawn from causes, effects, and ‘other collateral circumstances.

IV.     One’s judgement may be influenced in either direction by authority.
To consider aright the arguments to which we have made reference, one must have a certain degree of experience and skill. Those who do not have such skill and experience are bound to listen to the counsels of the wise, in order that they may rightly mold their practical judgement. For, on the testimony of Aristotle, ‘things generally admitted,’ or probable things, ‘are those which seem so to all, or to the majority, or at any rate to those who are wise; and again, of the wise, either to all, or to the majority, or to the more eminent.’ This method of judging is especially employed by kings, who hardly have the time to learn or to weigh thoroughly the principles of the branches of knowledge.

      The throng of wise men makes the ruler wise.

Aristides, addressing the Rhodians in his discourse On Concord, said that just as in questions of fact that is held to be true which is supported by the most and especially competent witnesses, so in matters of judgement we must follow the opinions which are supported by the more numerous and most eminent counselors. Thus the ancient Romans used not to make war without consulting the college of the Fetials, organized for this purpose, and the Christian Emperors rarely did so without giving a hearing to the bishops, that they might be advised of anything which might give rise to religious scruples.

V.     If in a weighty matter there is doubt on both sides, and one of two courses must be chosen, that which is the safer is to be adopted.
1.   In many controversies it may happen that strong arguments are forthcoming in support of both sides, whether drawn from the facts in the case or supported by the authority of others. When this occurs, if the matters which are in question are of slight moment the choice may evidently be free from harm, no matter on which side it may fall. But if the question is one of great importance, such as the infliction of capital punishment, in that case, because of the great difference between the courses to be chosen, the safer is to be preferred,’ as is commonly said:

      Nevertheless ’tis better on this side to err.

And so it is better to acquit one who is guilty than to condemn one who is innocent.

2.   The author of the Problems which are attributed to Aristotle says: ‘Each of us would prefer to acquit a guilty man on the ground that he had not done wrong than to condemn an innocent man for having done wrong’ (in this passage mh adikountoV is commonly read for adikountoV, and conversely). Shortly after he adds the reason, which we have already given: ‘For, whenever anyone is in doubt, he must choose that in which there is less wrong.’ Antiphon declares: ‘If it is necessary to err in any way, it is more in accordance with right to set free without justification than wrongfully to condemn. For in the one case a mistake is made, but the condemnation of an innocent person is a crime.’

VI.     Whence it follows that in case of doubt we must refrain from war.
Now war is of the utmost importance, seeing that in consequence of war a great many sufferings usually fall upon even innocent persons, Therefore in the midst of divergent opinions we must lean towards peace. Silius Italicus praises Fabius, for:

      With cautious mind the future did he scan,
      Nor took delight
      To stir up war for causes
      Slight and doubtful.

There are, moreover, three methods by which disputes may be prevented from breaking out into wars.

VII.     First, war may be obviated by a conference.
1.   The first method is by a conference. Says Cicero: ‘Since there are two methods of settling a difference, the one by argument, the other by force, and since the former is characteristic of men, the latter of beasts, we should have recourse to the second only when it is not permitted to use the first.’ And Terence has this:

      The wise man should try all things before arms;
      How know you if my bidding she will do
      Without constraint?

Apollonius Rhodius said:

      Not at once with force ere with words we try to win him;

and Euripides:

      With words shall I try to win; if that fails, then with force.

The same author in his Suppliants thus rebukes the states which have failed to try this method:

      You too, O cities, that by slaughter prefer
      To decide what words might settle.

Again, in the Iphigenia in Aulis, Achilles says:

    If he obeys the right, no need have you of aid
    From me; in this alone is there enough of safety.
    At once a friend’s good will shall I retain,
    And from my whole array less censure have,
    If this by reason, not by strife, I settle.

Also, in his Phoenician Maidens, we read this:

      For parley will accomplish all
      That foemen’s steel would e’er effect.

The same thought is more fully expressed in Livy by Phaeneas: ‘To avoid the necessity of fighting, men voluntarily relinquish many things which they could not be compelled to give up by war and force.’ In Book VII of Herodotus, Mardonius criticizes the Greeks in this regard: ‘They ought, speaking the same tongue, to settle their controversies by the use of heralds and envoys rather than by battle.’

2.   In Dionysius of Halicarnassus Coriolanus declares: ‘Not to desire the things of others, but to demand the things that are one’s own and, if these are not obtained, to fight for them, all would agree is fair.’ In the same Dionysius King Tullus says: ‘The things that cannot be settled by words are decided by arms.’ In Tacitus Vologeses uses these words: ‘What my ancestors had won I should have preferred to retain by justice rather than blood, by reason rather than arms.’ Says King Theodoric: ‘Then only is it expedient to resort to arms when justice cannot find a place among our adversaries.’

VIII.     Second, war may be obviated by arbitration; with a discussion of the duty of Christian kings in regard to warring parties.
1.   The second method is by agreement to arbitrate.’ This is applicable among those who have no common judicial authority. ‘It is not lawful,’ says Thucydides,’ to proceed against one who offers arbitration, just as against a wrong-doer.’ Thus, as Diodorus relates, Adrastus and Amphiaraus entrusted to Eriphyle the decision regarding the kingdom of Argos. Concerning Salamis three Lacedaemonians were chosen to judge between the Athenians and the Megareans. In Thucydides, who was just now quoted, the Corcyreans notify the Corinthians that they are ready to adjust their disputes before cities of the Peloponnesus upon which they shall mutually agree. Aristides praises Pericles because, to avoid war, he desired ‘to reach an agreement before a tribunal regarding their differences.’ Isocrates [Aeschines], in his speech Against Ctesiphon, commends Philip of Macedon for being ready’ to entrust to some fair and impartial city’ the settlement of the differences which he had with the Athenians.

2.   In like manner in former times the people of Ardea and Aricia, and afterwards the Neapolitans and the inhabitants of Nola, submitted their disputes to the judgement of the Roman people. The Samnites in a controversy with the Romans appealed to mutual friends. Cyrus brings in the king of India as an arbiter between himself and the king of Assyria. The Carthaginians in their quarrel with Masinissa appealed to legal tribunals in order to escape war.

In Livy the Romans themselves in the case of a controversy with the Samnites appeal to common allies. Philip of Macedon in his dispute with the Greeks says that he will accept the decision of peoples with whom both parties may be at peace. At the request of the Parthians and Armenians Pompey appointed arbitrators to fix their boundaries. Plutarch says that this was the chief duty of the Roman Fetiales, ‘not to permit military operations before all hope of a judicial settlement was cut off.’ Regarding the Druids in Gaul Strabo says: ‘Formerly they both served as arbitrators between those at war and often separated those who were about to engage in battle.’ The same author bears witness that in Spain the priests discharged the same function.

3.   Especially, however, Christian kings and states are bound to pursue this method of avoiding wars.’ For if certain arbiters were established both by Jews and by Christians in order that the sentences of strange judges might be avoided by those of the true faith, and this was prescribed by Paul, how much more should this be done to avoid a far greater disadvantage, that is, war? Thus Tertullian argues somewhere that the Christian must not serve as a soldier, seeing that he is not even permitted to go to law; but this argument, in accordance with what we have said in another place, is to be interpreted with a certain degree of moderation.

4.   Both for this and for other reasons it would be advantageous, indeed in a degree necessary, to hold certain conferences of Christian powers, where those who have no interest at stake may settle the disputes of others, and where, in fact, steps may be taken to compel parties to accept peace on fair terms. Diodorus and Strabo relate that this was the function of the Druids among the Gauls. We read also that the kings of the Franks entrusted the decision on the division of their kingdom to their leading men.

IX. Third, war may be obviated even by lot.
The third method is by lot. The use of the lot for this purpose was recommended by Dio Chrysostom in his second speech Against Fortune, and much earlier by Solomon (Proverbs 18:18).

X. Whether single combat may be permitted as a means of avoiding war.
1.   Something akin to the lot, furthermore, is single combat. Resort to single combat it does not seem necessary altogether to reject ‘if two persons, whose disputes would otherwise afflict whole peoples with very serious evils,’ are ready to settle their dispute by arms, as in olden times Hyllus and Echemus for the Peloponnesus, Hyperochus,, and Phemius for the country adjacent to the Inachus, Pyraechma at Aetolian and Degmenus the Epean for Elis, and Corbis and Orsua for Iba. In fact it seems clear that, if the combatants should themselves not act aright, assuredly the decision might be accepted by their states as the lesser evil. According to Livy, Metius addressed Tullus as follows:

Let us Follow some course by which it may be decided which people shall rule the other, without a great disaster and without much bloodshed of either people.

Strabo says that this was the ancient custom of the Greeks; and in Virgil Aeneas says that it was right that the dispute between himself and Turnus should be decided in this way.

2.   This, among other customs of the ancient Franks, is strongly commended by Agathias in his first book, and I shall cite his own words because they are notable

But if it should happen that any disputes arise between their kings, then all form a line of battle for the purpose of waging war and reaching a decision by force of arms, and they march to meet one another. But when the armies on either side behold each other, straightway they cast aside their anger and change to friendship, and they bid their kings to settle their disputes rather by arbitration. If these are unwilling to do this, they bid their kings to fight in single combat and incur danger in their own persons, on the ground that it is not just and right, nor in accord with the practices of their forefathers, that because of their private enmity they should weaken or destroy the common good.

Immediately, therefore, they disband their armies; with the restoration of peace they enjoy intercourse with one another in safety, since the causes of the troubles have been removed. So great among their subjects is the zeal for justice and the love of country; and, on the other hand, the spirit of their rulers is mild and easily persuadable by their subjects.

XI.     Where the doubt on either side is equal, he who is in possession has the more advantageous position.
Although when the cause involves doubt each party is bound to try to find conditions under which war may be avoided, nevertheless the party who asserts claims is under greater obligation to do this than the party who is in possession.’ For it is in accordance not only with the civil but also with the law of nature, that when each party; has a cause equally just the case of the party having possession is the better. The reason for this we have adduced elsewhere from the, Problems which are attributed to Aristotle.

At this point we must add that war cannot permissibly be waged by him who knows that he has a just cause but has not adequate proofs to convince the possessor of the injustice of his possession; the reason is that he does not have the right to compel the other to surrender possession.

XII.     When the doubt on either side is equal, if neither party is in possession the thing under dispute should be divided.
In cases in which the right is in doubt, and neither party is in possession, or each holds possession in an equal measure, he is to be considered in the wrong who rejects a proposed division of the thing under dispute.

XIII.     The question whether a war may be just from the view point of both parties is discussed, with many qualifications.
1.   From what we have said it is possible to reach a decision ‘regarding the question, which has been discussed by many, whether, if we take into consideration the prime movers, a war may be considered just from the point of view of each of the opposing sides.

We must distinguish various interpretations of the word ‘just.’;Now a thing is called just either from its cause, or because of its effects; and again, if from its cause, either ‘in the particular ‘sense of justice, or in the general sense in which all right conduct comes under this name. Further, the particular sense may cover either that which concerns the deed, or that which concerns the doer; for sometimes the doer himself is said to act justly so long as he does not act unjustly, even if that which he does is not just. This distinction between ‘acting wrongly’ (to adikein) and ‘doing that which is unjust’ (to adikon prattein) is rightly made by Aristotle.

2.   In the particular sense and with reference to the thing itself, a war cannot be just on both sides, just as a legal claim cannot; the reason is that by the very nature of the case a moral quality cannot be given to opposites as to doing and restraining. Yet it may actually happen that neither of the warring parties does wrong. No one acts unjustly without knowing that he is doing an unjust thing, but in this “respect many are ignorant. Thus either party may justly, that is in good faith, plead his case. For both in law and in fact many things out of which a right arises ordinarily escape the notice of men.

3.   In the general sense that is usually called just which is free from all blame on the part of the doer. However, many things are done without right and yet without guilt, because of unavoidable ignorance. An example of this is the case of those who fail to observe a law of which they are ignorant through no fault of their own, after the law itself has been promulgated and a sufficient time has elapsed” for them to know of it. So it may happen in the case of legal claims also, that each party is guiltless, not only of injustice, but also of any other fault; this is especially true where each party, or even one of the two, pleads not in his own name but in the name of another, for example because of his duty as a guardian, which cannot abandon a right even if it is uncertain.

In this sense Aristotle declares that in suits concerning a disputed’ right neither party is dishonorable or, as he says,’ wicked.’ In agreement therewith Quintilian says that it may happen that an orator, that is a good man, may speak on either side. Furthermore Aristotle also says that a judge is said to judge justly in a twofold sense, for this means that he judges either’ as he ought,’ without any ignorance, or; ‘in accordance with his own judgement.’ And in another place he says: ‘If a judge has rendered judgement through ignorance, he is not unjust.’

4.   In the case of war, however, it is scarcely possible that rashness and lack of kindly feeling should not play some part, because of the seriousness of the business. The seriousness of war is in all respects such that, not satisfied with merely acceptable causes, it demands causes that are perfectly evident.

5.   If we interpret the word ‘just’ in relation to certain legal effects, in this sense surely it may be admitted that a war may be just from the point of view of either side; this will appear from what we shall have to say later regarding a formal public war. So, in fact, a judgement not rendered according to law, and possession without right, have certain legal effects.