De Specialibus Legibus (lib. i‑iv)

But if any one being compelled to swear, swears by anything whatever in a manner which the law does not forbid, let him exert himself with all his strength and by every means in his power to give effect to his oath, interposing no hindrance to prevent the accomplishment of the matter thus ratified, especially if neither implacable anger or frenzied love, or unrestrained appetites agitate the mind, so that it does not know what is said or done, but if the oath has been taken with sober reason and deliberate purpose.

For what is better than to speak with perfect truth throughout one’s whole life, and to prove this by the evidence of God himself? For an oath is nothing else but the testimony of God invoked in a matter which is a subject of doubt, and to invoke God to witness a statement which is not true is the most impious of all things.

For a man who does this, is all but saying in plain words (even though he hold his peace), "I am using thee as a veil for my iniquity; do thou co-operate with me, who am ashamed to appear openly to be behaving unjustly. Do thou incur the blame instead of me, who am acting unjustly. For though I am doing wrong, I am anxious not to be accounted wicked, but thou canst be indifferent to thy reputation with the multitude, having no regard to being well spoken of." But to say or imagine such things as these is most impious, for not only would God, who is free from all participation in wickedness, but even any father or any stranger, provided he were not utterly devoid of all virtue, would be indignant if he were addressed in such a way as this.

A man, therefore, as I have said, must be sure and give effect to all oaths which are taken for honourable and desirable

for there are some men who swear, if chance so prompts them, to commit theft, or sacrilege, or adultery, or rape, or to inflict wounds or slaughter, or any similar acts of wickedness, and who perform them without any delay, making an excuse that they must keep their oaths, as if it were not better and more acceptable to God to do no iniquity, than to perform such a vow and oath as that. The national laws and ancient ordinances of every people are established for the sake of justice and of every virtue, and what else are laws and ordinances but the sacred words of nature having an authority and power in themselves, so that they differ in no respect from oaths?

And let every man who commits wicked actions because he is so bound by an oath, beware that he is not keeping his oath, but that he is rather violating one which is worthy of great care and attention to preserve it, which sets a seal as it were to what is honourable and just, for he is adding wickedness to wickedness, adding lawless actions to oaths taken on improper occasions, which had better have been buried in silence.

Let such a man, therefore, abstain from committing iniquity, and seek to propitiate God, that he may grant to him the mercy of that humane power which is innate in him, so as to pardon him for the oaths which he took in his folly. For it is incurable madness and insanity to take upon himself twofold evils, when he might put off one half of the burden of them.

But there are some men who, out of the excess of their wicked hatred of their species, being naturally unsociable and inhuman, or else being constrained by anger as by a hard mistress, think to confirm the savageness of their natural . disposition by an oath, swearing that they will not admit this man or that man to sit at the same table with them, or to - come under the same roof; or, again, that they will not give any assistance to such an one, or that they will not receive