There is a palpable contradiction between the laws and the natural sentiments of mankind in the case of oaths, which are administered to a criminal to make him speak the truth, when the contrary is his greatest interest; as if a man could think himself obliged to contribute to his own destruction, and as if, when interest speaks, religion was not generally silent, religion, which in all ages hath, of all other things, been most commonly abused: and indeed, upon what motive should it be respected by the wicked, when it has been thus violated by those who were esteemed the wisest of men? The motives which religion opposes to the fear of impending evil and the love of life are too weak, as they are too distant, to make any impression on the senses. The affairs of the other world are regulated by laws entirely different from those by which human affairs are directed; why then should you endeavour to compromise matters between them? Why should a man be reduced to the terrible alternative, either of offending God, or of contributing to his own immediate destruction? The laws which require an oath in such a case leave him only the choice of becoming a bad Christian or a martyr. For this reason, oaths become, by degrees, a mere formality, and all sentiments of religion, perhaps the only motive of honesty in the greatest part of mankind, are destroyed. Experience proves their inutility: I appeal to every judge, whether he has ever known that an oath alone has brought truth from the lips of a criminal; and reason tells us, it must be so; for all laws are useless, and in consequence destructive, which contradict the natural feelings of mankind. Such laws are like a dike, opposed directly to the course of a torrent; it is either immediately overwhelmed, or, by a whirlpool formed by itself, it is gradually undermined and destroyed.
Back to: Of pecuniary Punishments. [Chapter 17, Of Crimes and Punishments]