The Rights of War and Peace

by Hugo Grotius

From the above arguments it is easy to comprehend what is to be thought of an oath fraudulently obtained. For if it is certain that a person took the oath upon a supposition, which afterwards was proved to have no foundation, and but for the belief of which he would never have taken it, he will not be bound by it. But if it appears that he would have taken it without that supposition; he must abide by his oath, because oaths allow of no evasion.

III. The meaning of an oath should not be stretched beyond the usual acceptation of words. Therefore there was no breach of their oath in those, who, having sworn that they would not give their daughters in marriage to the Benjamites, permitted those that had been carried off to live with them. For there is a difference between giving a thing, and not recovering that which is lost.

IV. To give validity to an oath, the obligation, which it imposes ought to be lawful. Therefore a sworn promise, to commit an illegal act, to do any thing in violation of natural or revealed law, will be of no effect.

V. Indeed if a thing promised upon oath be not actually illegal, but only an obstruction to some greater moral duty, in that case also the oath will not be valid. Because it is a duty which we owe to God not to deprive ourselves of the freedom of doing all the good in our power.

VI. Oaths may differ in form, and yet agree in substance. For they all ought to include an appeal to God, calling upon him to witness the truth, or to punish the falsehood of their assertions, both of which amount to the same thing. For an appeal to the testimony of a superior, who has a right to punish, is the same as requiring him to avenge an act of perfidy. Now the omniscience of God gives him power to punish, as well as to witness every degree of falsehood.

VII. It was a custom with the ancients to swear by persons or beings expressly distinct from the supreme creator, either imprecating the wrath of those by whom they swore, whether it were the sun, the heavens, or the earth; or swearing by their own heads, by their children, their country or their prince, and calling for destruction upon THEM, if there were any falsehood in their oaths.

Nor was this practice confined to Heathen nations only, but, as we are informed by Philo, it prevailed among the Jews. For he says that we ought not, in taking an oath upon every occasion, to have recourse to the maker and father of the universe, but to swear by our parents, by the heavens, the earth, the universe. Thus Joseph is said to have sworn by the life of Pharaoh, according to the received custom of the Egyptians. Nor does our Saviour, in the fifth chapter of St. Matthew's Gospel, intend, as it is supposed by some, to consider these oaths to be less binding than those taken expressly by the name of God. But as the Jews were too much inclined to make use of, and yet disregard them, he shews them that they are real oaths. For, as Ulpian has well observed, he who swears by his own life, seems to swear by God, bearing a respect and reference to his divine power. In the same manner Christ shews that he, who swears by the temple, swears by God who presides in the temple, and that he who swears by Heaven, swears by God, who sits upon the Heavens. But the Jewish teachers of that day thought that men were not bound by oaths made in the name of created beings, unless some penalty were annexed, as if the thing, by which they swore, were consecrated to God. For this is the kind of oath implied in the word κορβᾶν {korban} as BY A GIFT. And it is this error of theirs, which Christ refutes.

VIII. The principal effect of oaths is to cut short disputes. "An oath for confirmation, as the inspired writer of the Epistle to the Hebrews has said, is the end of all strife." So too we find in Diodorus Siculus, that an oath was regarded among the Egyptians as the surest pledge of sincerity that men could give. So that every one, in taking an oath, should express the real purpose of his mind, and render his actions conformable to those expressions. There is a beautiful passage on this subject, in Dionysius of Halicarnassus, who says, "the last pledge among men, whether Greeks or Barbarians, and it is a pledge, which no time can blot out, is that which takes the Gods, as witnesses to oaths and covenants."

IX. The substance of an oath too should be such, and conceived in such words, as to include not only the divine, but the human obligations, which it implies. For it should convey to the person, who receives it, the same security for his right, as he would derive from an express promise or a contract. But if either the words bear no reference to a person so as to confer upon him a right, or if they do refer to him but in such a manner that some opposition may be made to his claim, the force of the oath will, in that case, be such as to give that person no right from it; yet he who has taken it must still submit to the divine obligation, which the oath imposes. An example of which we have in a person, from whom a sworn promise has been extorted by fear. For here the oath conveys no right, but what the receiver ought to relinquish, for it has been obtained to the prejudice of the giver. Thus we find the Hebrew Kings were reproved by the prophets, and punished by God for not observing the oaths, which they had taken to the kings of Babylon.

X. The same rule applies not only to transactions between public enemies, but to those between any individuals whatsoever. For he, to whom the oath is taken, is not the only person to be considered; but a solemn regard must be paid to God, in whose name the oath is taken, and who possesses authority to enforce the obligation. For which reason it is impossible to admit the position of Cicero, that it is no breach of an oath to refuse paying to robbers the sum stipulated for having spared one's life; because such men are not to be ranked in the number of lawful enemies, but treated as the common enemies of all mankind, so that towards them no faith ought to be kept, nor even the sanctity of an oath observed.