De Specialibus Legibus (lib. i‑iv)

In the treatise preceding this one we have discussed with accuracy two articles of the ten commandments, that which relates to not thinking that any other beings are absolute gods, except God himself; and the other which enjoins us not to worship as God any object made with hands. And we also spoke of the laws which relate specially to each of these points. But we will now proceed to discuss the three which come next in the regular order, again adapting suitable special laws to each.

And the first of these other commandments is not to take the name of God in vain; for the word of the virtuous man, says the law, shall be his oath, firm, unchangeable, which cannot lie, founded steadfastly on truth. And even if particular necessities shall compel him to swear, then he should make the witness to his oath the health or happy old age of his father or mother, if they are alive; or their memory, if they are dead.

One person is recorded in the law, one of the patriarchs of the race, and one of those most especially admired for his wisdom, "as swearing by the face of his father," for the benefit, I imagine, of all those who might live afterwards, and with the object of giving necessary instruction, so that posterity might honour their parents in the proper manner, loving them as benefactors and respecting them as rulers appointed by nature, and might therefore not rashly invoke the name of God.

And these men also deserve to be praised who, when they are compelled to swear, by their slowness, and delay, and evasion, cause fear not only to those who see them, but to those also who invite them to take an oath; for when they do pronounce the oath they are accustomed to say only thus much, "By the—;" or, "No, by the—;" without any further addition, giving an emphasis to these words by the mutilation of the usual form, but without uttering the express oath.

However, if a man must swear and is so inclined, let him add, if he pleases, not indeed the highest name of all, and the most important cause of all things, but the earth, the sun, the stars, the heaven, the universal world; for these things are all most worthy of being named, and are more ancient than our own birth, and, moreover, they never grow old, lasting for ever and ever, in accordance with the will of their Creator.

And some men display such easiness and indifference on the subject, that, passing over all created things, they dare in their ordinary conversation to rise up to the Creator and Father of the universe, without stopping to consider the place in which they are, whether it be profane or sacred; or the time, whether it be suitable; or themselves, whether they are pure in body and soul; or the business, whether it be important; or the occasion, whether it is necessary; but (as the proverb says), they pollute everything with unwashed feet, as if it were decent, since nature has bestowed a tongue upon them, for them to let it loose unrestrained and unbridled to approach objects which it is impious to approach.

When they ought rather to employ that most excellent of all the organs by which voice and speech (the most useful things in human life, and the causes of all communion among men)

But now, out of their excessive impiety, they use the most awful names in speaking of the most unimportant matters, and heaping one appellation upon another in a perfect crowd they feel no shame, thinking that by the frequency and number of their uninterrupted oaths they will attain to the object which they desire, being very foolish to think so; for a great number of oaths is no proof of credibility, but rather of a man’s not deserving to be believed in the opinion of men of sense and wisdom.