Commentary on the Law of Prize and Booty. Hugo Grotius

damage previously done. For, inasmuch as his act is adapted to the purposes of war, he is not guiltless after aiding the unjust belligerent, however thoughtlessly he may have done so. In other words, his conduct is similar to that of a man who, moved by pity,^a has delivered a debtor from prison, or pointed out means of flight to a criminal, [or caused unjust losses to the side he opposes when acting as]²¹ advocate in a lawsuit;^b for, according [50′ a′] to the opinion invariably expressed by learned authorities, the perpetrator of any of these acts is in every case bound by an obligation to make reparation. This is the purport of the reply given by Amalasuntha to Justinian, to the effect that they who aid the enemy by supplying him with the necessities of war, are to be regarded as enemies.^{c 22} Again, if the commodities supplied should be of a nature not essentially directed to the purposes of war, but nevertheless such as to furnish the unjust party with a means of prolonging the conflict, then the same conclusion will hold true, always provided that the conveyor was in a position where he ought to have been aware of that fact. If he was not in such a position, he should not be held culpable unless the state waging a just war has formally notified him of this very circumstance, appending proof of the justice [of its cause].^d An outstanding argument in support of this distinction can be drawn from the words of Seneca,^e who holds that in the repayment of benefits received from a tyrant moderation should be observed, in accordance with the following rule: “If the benefit bestowed upon the tyrant by me [in return for benefits received], is likely neither to increase his power to do general harm, nor to strengthen the power already possessed by him; and if the benefit in question be one that enables me to repay him without causing public disaster, I shall render that payment.” A little further on, Seneca adds: “I shall not provide money which will serve him as wages to maintain a bodyguard.” And again: “I shall not furnish him with soldiers and arms.” The same author declares that he would send the tyrant pleasure-boats, but would refuse to send him triremes [i.e. warships]. In short, the greater the estimate of the loss, or of the impediment to the process of compelling the enemy to obey the law, that has resulted from such services, the further one may proceed in seizing spoils by way of reparation without resorting to additional judicial measures; for that very attempt to obtain reparations is in a sense one of the consequences of the war.

      Corollary I

      Returning from this digression to our discussion of just forms of warfare against subjects, we find that the observations already assembled on this point, constitute in their entirety an opinion which may be [50′] impressed upon our memory in the following terms: Bodily hurt is justly inflicted upon subjects in so far as they either deserve it because of wrongdoing,^a or impede (albeit in ignorance) the execution [of justice]; but prize or booty is justly taken from all subjects, at any time, up to the full amount of the debt owed. [51]

      Now that we have seen how the laws of the second order [Laws III and IV] may be reconciled with the waging of wars, let us turn our attention to the Third Rule.

      In accordance with this rule, it is our duty to fulfil, regardless of possible harmful consequences to ourselves, whatever promises we have made, in relation of course to matters under our control. This admonition is not incompatible with the Second Law;^b for our own possessions are subject to our own will, and they are dispensed in conformity with that precept which I have called the Third Rule, an assertion that will be more readily intelligible if viewed in the light of the observations made by us at the outset.

      Accordingly, if the law of nations is taken as a criterion rather than some civil precept, faith must be kept with the enemy in every way (as Cicero^a maintains), and even (so Ambrose^b specifies) when one is dealing with a treacherous enemy. It should be understood, however, that the foregoing doctrine is dependent upon the supposition that the enemy has not previously departed from the particular contract^c that is the basis of the required good faith;^d for in such cases it will be evident, inasmuch as the obligation is mutual, that the terms of the promise have lapsed, so to speak. Apart from this one exception, it may be said that,

      He is the best of soldiers who aims first

       And last, ’mid wars, to keep good faith intact.^e

      Neither, then, can fear be accepted as an excuse, since even he who has made a promise in order to escape misfortune cannot deny that he himself chose this course of action in preference to the alternative course. In short, will that is thus coerced nevertheless retains its voluntary character and, once it has been expressed (albeit to an adversary), has binding force. With respect to this point, we should abide by the opinion of the theologians^f rather than by that of the jurists. For the former follow the guidance of natural reason, whereas the latter are guided by civil precepts, which frequently, for the sake of some advantage, permit an act that would not otherwise be permitted.

      New explanation

      Moreover, the will is bound not only by treaties and pacts, but also by agreements tacitly indicated. For example, any person who has placed himself under the protection of another in such a way as to be in the possession and under the power of that protector, makes himself for the time being a part, as it were, of the latter, and by his silence promises clearly enough that he will devise nothing prejudicial to the welfare and sovereign status of the said protector. Thus we abhor traitors and [51′] suborned assassins and—far more intensely—poisoners.^a