Hugo Grotius (15831645). The Rights of War and Peace. 1901.
Chapter XXIV: On Tacit Faith
Tacit1 faithExample of in desiring to be taken under the protection of a king or nationImplied in the demand or grant of a conferenceAllowable for the party seeking it to promote his own interest thereby provided he uses no treacheryMeaning of mute signs allowed by custom.
I. BOTH public, private, and mixed, conventions admit of tacit consent, which is allowed by custom. For in whatever manner consent is indicated and accepted it has the power of conveying a right. And, as it has been frequently observed in the course of this treatise, there are other signs of consent besides words and letters: some of them indeed naturally rising out of the action itself.
II. An example of such tacit agreement may be found in the case of a person coming from an enemy, or foreign country, and surrendering himself to the good faith of another king or people. For such a one tacitly binds himself to do nothing injurious or treacherous to that state, where he seeks protection, a point which is beyond all doubt.
III. In the same manner, a person who grants or requests a conference, gives a tacit promise, that he will do nothing prejudicial to the parties, who attend it. Livy pronounces an injury done to an enemy, under the pretext of holding a conference, a violation of the law of nations.
IV. But such a tacit promise, to take no advantage of a parley or conference, is not to be carried farther than what has been said. Provided all injury and injustice are avoided, it is reckoned a lawful stratagem, for any one to avail himself of a parley in order to draw off the enemys attention from his military projects, and to promote his own. The device, by which Asdrubal extricated his army from the Ausetanian forests, was of this kind, and by the same means Scipio Africanus, the elder, gained a perfect knowledge of Syphaxs camp. Both these circumstances are related by Livy.
V. There are certain mute signs, deriving all their force and meaning from custom; such as the fillets, and branches of olive formerly used: among the Macedonians pikes erected, and among the Romans shields placed upon the head, were signs of a suppliant surrender obliging the party to lay down his arms. In the present day a white flag is a sign of suing for a parley. Therefore all these methods have the force of express declarations.